SPIN-COATABLE METAL DOPED SILICON-CONTAINING FILM-FORMING COMPOSITIONS AND PROCESSES OF USING THEM FOR DEPOSITION
20250223704 · 2025-07-10
Assignee
Inventors
Cpc classification
C23C18/1204
CHEMISTRY; METALLURGY
C23C18/1295
CHEMISTRY; METALLURGY
International classification
Abstract
A metal doped silicon-containing film-forming composition for forming a metal doped silicon-containing film comprises: 1) at least one silicon-containing precursor, 2) a metal precursor, and 3) a solvent, wherein the metal precursor is selected from an alkyl metal, alkyl metalloxane or polymetalloxane, wherein the metal doped silicon-containing film-forming composition is capable of forming the metal doped silicon-containing film.
Claims
1. A metal doped silicon-containing film-forming composition for forming a metal doped silicon-containing film, the composition comprising: i) at least one silicon-containing precursor; ii) a metal precursor; and iii) a solvent, wherein the metal precursor is selected from an alkyl metal, alkyl metalloxane or polymetalloxane; wherein the metal doped silicon-containing film-forming composition is capable of forming the metal doped silicon-containing film.
2. The composition of claim 1, wherein the at least one silicon precursor is a compound comprising an aminosilane having the formula:
[(R.sup.1).sub.2-mNH.sub.m].sub.nSi(R.sup.2).sub.4-n, wherein each R.sup.1 is independently selected from alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from hydrogen, alkyl, vinyl, allyl, and phenyl; and n=1-4, m=0 or 1; a compound comprising an aminopolysilane with a repeating unit having the formula: [(R.sup.1.sub.2-mNH.sub.m).sub.nSi.sub.p(R.sup.2).sub.q], where each R.sup.1 is independently selected from alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0-2, m=0 or 1, p2, q=0-2; and a terminal group having the formula: [(R.sup.1.sub.2-mNH.sub.m).sub.n(R.sup.2).sub.3-nSi], wherein each R.sup.1 is independently selected from alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0-3, m=0 or 1; a compound comprising an alkoxysilane having the formula: [R.sup.1O].sub.nSi(R.sup.2).sub.4-n, wherein each R.sup.1 is independently selected from alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from hydrogen, alkyl, vinyl, allyl, and phenyl; and n=1-4; a compound comprising an alkoxypolysilane with a repeating unit having the formula: [(R.sup.1O).sub.nSi.sub.p(R.sup.2).sub.q], wherein each R.sup.1 is independently selected from alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0-2, p2, q=0-2; and a terminal group having the formula: [(R.sup.1O).sub.n(R.sup.2).sub.3-nSi], wherein each R.sup.1 is independently selected from alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from the group consisting of hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0-3; a compound comprising NH and silicon-containing molecules, including polysilazane, with a repeating unit selected from the general formulae (1a), (1b), (1c), and a terminal group of the formula NH.sub.2 or SiH.sub.3. ##STR00005## a compound comprising a polysilane with a repeating unit having the formula: [SiR.sup.1.sub.n], wherein each R.sup.1 is independently selected from the group consisting of hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0-2; and a terminal group of SiH.sub.3. a compound comprising a polysilazane with a repeating unit selected from the general formulae (2a), (2b), (2c), (2d), (2e), and (2f) and a terminal group of SiH.sub.3: ##STR00006## a compound having a polysiloxane with a repeating unit of the formula: [O(R.sup.1O).sub.nSi(R.sup.2).sub.2-n], where each R.sup.1 is selected from the group consisting of hydrogen or alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from the group consisting of hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0, 1 or 2, and a terminal group of the formula: [(R.sup.1O).sub.n(R.sup.2).sub.3-nSi], where each R.sup.1 is independently selected from the group consisting of hydrogen or alkyl groups of Cito C.sub.6; each R.sup.2 is independently selected from the group consisting of hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0, 1, 2 or 3.
3. The composition of claim 1, wherein the at least one silicon precursor contains nitrogen, oxygen, or a combination of nitrogen and oxygen.
4. The composition of claim 1, wherein the at least one silicon precursor are selected from the group consisting of polysilanes, polysilazanes, aminosilanes, aminopolysilanes, alkoxysilanes, and alkoxypolysilanes.
5. The composition of claim 1, wherein the at least one silicon precursor are selected from tetrakis(dimethylamino) silane, tris(dimethylamino) silane, poly(1,1-dimethylsilazane), polyvinylsilazane, trimethoxysilane, triisopropylsilane, ethoxy-nonamethyltetrasilane, methoxy octamethyltetrasilane, perhydropolysilazane, polymethylsilane, poly(methylphenyl) silane, polymethylhydroxosiloxane, polydimethylsiloxane, poly(ethyl methyl) siloxane, or polymethylhydrosiloxane.
6. The composition of claim 1, wherein the amount of the metal precursor ranges between approximately 0.5% w/w and approximately 99.5% w/w.
7. The composition of claim 1, wherein the amount of the at least one silicon-containing precursor ranges from about 0.005 to 60 mol % based on the mole of the metal precursor present.
8. The composition of claim 1, wherein a metal in the metal precursor is selected from Al, Ti, Zr, Sn, Ni, W, Hf, Ta, B, Ga, Cr, Ge, or In.
9. The compositions of claim 10, wherein the amount of the metal in the metal precursor ranges from about 0.01% wt/wt to 80% wt/wt.
10. The composition of claim 1, wherein the metal precursor is an aluminium precursor selected from an alkyl aluminium selected from trimethylaluminum, triethylaluminum, trioctylaluminum, or tri(Isobutyl)aluminium, or an alkyl aluminiumloxanes or polyalkyl aluminiumloxanes selected from polymethylaluminoxane, methylaluminoxane, modified methylaluminoxane, Isobutylaluminoxane, or tetraisobutyldialuminoxane.
11. The composition of claim 1, wherein the solvent is a solvent mixture, each solvent has different boiling points in order to adjust the composition viscosity or deposited film thickness.
12. The composition of claim 1, further comprising a crosslinking catalyst, wherein the crosslinking catalyst is present in an amount of 0.01 to 10 parts by weight, based on 100 parts by weight of the metal precursor.
13. A process for forming a metal doped silicon-containing film, the process comprising: treating the surface of a substrate to reduce the surface energy of the substrate; applying a metal doped silicon-containing film-forming composition onto the substrate to form a deposited film thereon through a deposition method; and heating the substrate with the deposited film in an oxygen- or nitrogen-containing atmosphere at temperatures characterized as sufficient to remove an organic part of the deposited film to form the metal doped silicon-containing film, wherein the metal doped silicon-containing film-forming composition comprising: i) at least one silicon-containing precursor; ii) a metal precursor; and iii) a solvent, wherein the metal precursor is selected from an alkyl metal, alkyl metalloxane or polymetalloxane; wherein the metal doped silicon-containing film-forming composition is capable of forming the metal doped silicon-containing film.
14. The process of claim 13, wherein the temperatures range from approximately 40 C. to approximately 1500 C.
15. The process of claim 13, wherein the deposition method includes a spin coating, spray coating, dip coating, or slit coating technique.
16. The process of claim 13, further comprising the steps of pre-baking the deposited film under N.sub.2 atmosphere at a temperature ranging from approximately 40 C. to 400 C.; and subsequently hardbaking the deposited by a heat-induced radical reaction or a UV-Vis photo induced radical reaction in an atmosphere of O.sub.2, O.sub.3, H.sub.2O, H.sub.2O.sub.2, N.sub.2O, or NO, air, compressed air, or combinations thereof at a temperature range of 200-1500 C. to convert the deposited film to the metal doped silicon-containing film.
17. The process of claim 13, wherein the metal doped silicon-containing film is a SiMO.sub.x, SiMO.sub.xN.sub.y, SiMO.sub.xC.sub.y, SiMN.sub.x, or SiMO.sub.xC.sub.yN.sub.z film, wherein M is selected from Al, Ti, Zr, Sn, Ni, W, Hf, Ta, B, Ga, Cr, Ge, or In, and x, y and z are integers.
18. The process of claim 13, further comprising the step of adding a reactive gas to the composition, wherein the reactive gas is selected from a reduced agent H.sub.2, an N-source selected from NH.sub.3 or hydrazines, or an oxidizing agent selected from O.sub.2, O.sub.3, ambient air, compressed dry air, humid air, H.sub.2O, H.sub.2O.sub.2, organic peroxides, NO, N.sub.2O, NO.sub.2, CO, CO.sub.2, SO.sub.2 or combinations thereof.
19. A metal doped silicon-containing film comprising an etch rate selectivity to a silicon oxide film or silicon nitride film greater than 5; and a film shrinkage ranging from approximately 0% to approximately 40%.
20. The metal doped silicon-containing film of claim 19 being a metal doped silicon-containing filing gap, wherein a gap to be filled has an aspect ratio ranging from approximately 1:1 to approximately 200:1, and a critical dimension ranging from approximately 1 nanometer to approximately 10 micrometers.
21. The composition of claim 13, wherein the at least one silicon precursor is a compound comprising an aminosilane having the formula:
[(R.sup.1).sub.2-mNH.sub.m].sub.nSi(R.sup.2).sub.4-n, wherein each R.sup.1 is independently selected from alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from hydrogen, alkyl, vinyl, allyl, and phenyl; and n=1-4, m=0 or 1; a compound comprising an aminopolysilane with a repeating unit having the formula: [(R.sup.1.sub.2-mNH.sub.m).sub.nSi.sub.p(R.sup.2).sub.q], where each R.sup.1 is independently selected from alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0-2, m=0 or 1, p2, q=0-2; and a terminal group having the formula: [(R.sup.1.sub.2-mNH.sub.m).sub.n(R.sup.2).sub.3-nSi], wherein each R.sup.1 is independently selected from alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0-3, m=0 or 1; a compound comprising an alkoxysilane having the formula: [R.sup.1O].sub.nSi(R.sup.2).sub.4-n, wherein each R.sup.1 is independently selected from alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from hydrogen, alkyl, vinyl, allyl, and phenyl; and n=1-4; a compound comprising an alkoxypolysilane with a repeating unit having the formula: [(R.sup.1O).sub.nSi.sub.p(R.sup.2).sub.q], wherein each R.sup.1 is independently selected from alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0-2, p2, q=0-2; and a terminal group having the formula: [(R.sup.1O).sub.n(R.sup.2).sub.3-n Si], wherein each R.sup.1 is independently selected from alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from the group consisting of hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0-3; a compound comprising NH and silicon-containing molecules, including polysilazane, with a repeating unit selected from the general formulae (1a), (1b), (1c), and a terminal group of the formula NH.sub.2 or SiH.sub.3. ##STR00007## a compound comprising a polysilane with a repeating unit having the formula: [SiR.sup.1.sub.n], wherein each R.sup.1 is independently selected from the group consisting of hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0-2; and a terminal group of SiH.sub.3. a compound comprising a polysilazane with a repeating unit selected from the general formulae (2a), (2b), (2c), (2d), (2e), and (2f) and a terminal group of SiH.sub.3: ##STR00008## a compound having a polysiloxane with a repeating unit of the formula: [O(R.sup.1O).sub.nSi(R.sup.2).sub.2-n], where each R.sup.1 is selected from the group consisting of hydrogen or alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from the group consisting of hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0, 1 or 2, and a terminal group of the formula: [(R.sup.1O).sub.n(R.sup.2).sub.3-n Si], where each R.sup.1 is independently selected from the group consisting of hydrogen or alkyl groups of Cito C.sub.6; each R.sup.2 is independently selected from the group consisting of hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0, 1, 2 or 3.
22. The composition of claim 13, wherein the at least one silicon precursor contains nitrogen, oxygen, or a combination of nitrogen and oxygen.
23. The composition of claim 13, wherein the at least one silicon precursor are selected from the group consisting of polysilanes, polysilazanes, aminosilanes, aminopolysilanes, alkoxysilanes, and alkoxypolysilanes.
24. The composition of claim 13, wherein the at least one silicon precursor are selected from tetrakis(dimethylamino) silane, tris(dimethylamino) silane, poly(1,1-dimethylsilazane), polyvinylsilazane, trimethoxysilane, triisopropylsilane, ethoxy-nonamethyltetrasilane, methoxy octamethyltetrasilane, perhydropolysilazane, polymethylsilane, poly(methylphenyl) silane, polymethylhydroxosiloxane, polydimethylsiloxane, poly(ethyl methyl) siloxane, or polymethylhydrosiloxane.
25. The composition of claim 13, wherein a metal in the metal precursor is selected from Al, Ti, Zr, Sn, Ni, W, Hf, Ta, B, Ga, Cr, Ge, or In.
26. The compositions of claim 13, wherein the amount of the metal in the metal precursor ranges from about 0.01% wt/wt to 80% wt/wt.
27. The composition of claim 13, wherein the metal precursor is an aluminium precursor selected from an alkyl aluminium selected from trimethylaluminum, triethylaluminum, trioctylaluminum, or tri(Isobutyl)aluminium, or an alkyl aluminiumloxanes or polyalkyl aluminiumloxanes selected from polymethylaluminoxane, methylaluminoxane, modified methylaluminoxane, Isobutylaluminoxane, or tetraisobutyldialuminoxane.
28. The composition of claim 13, wherein the amount of the metal precursor ranges between approximately 0.5% w/w and approximately 99.5% w/w.
29. The composition of claim 13, wherein the amount of the at least one silicon-containing precursor ranges from about 0.005 to 60 mol % based on the mole of the metal precursor present.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0099] For a further understanding of the nature and objects of the present invention, reference should be made to the following detailed description, taken in conjunction with the accompanying drawings, in which like elements are given the same or analogous reference numbers and wherein:
[0100]
DESCRIPTION OF PREFERRED EMBODIMENTS
[0101] Disclosed are spin-coatable metal-containing silicon-containing film-forming compositions and processes of using them. More specifically, the disclosed are spin-on metal doped silicon-containing film-forming compositions or metal doped silicon-containing film-forming compositions for forming metal doped silicon-containing films. The metal doped silicon-containing film may a SiMO.sub.x, SiMO.sub.xN.sub.y, SiMO.sub.xC.sub.y, SiMN.sub.x, or SiMO.sub.xC.sub.yN.sub.z film used for photolithographic processes and direct patternable layer, for via or trench filling, for anti-reflective coatings, optical and multi-color pattern etch applications, in which M is selected form Al, Ti, Zr, Sn, Ni, W, Hf, Ta, B, Ga, Cr, Ge, In, or the like and x, y and z each are an integer. The disclosed includes preparation of the spin-coatable metal doped silicon-containing film-forming compositions from alkyl metal, alkyl metalloxane or polymetalloxane solutions in presence of a silicon precursor to form a film, which has high metal-oxide and/or metal-nitride content. Specifically, SiMO.sub.x films form good quality films when applied from a solvent onto a substrate demonstrating good dry etch resistance in fluoride-containing plasmas. The SiMO.sub.x materials may be easily removed using standard wet chemicals such as SC1 and diluted HF. The SiMO.sub.x materials may be used as gap fill materials to fill particular openings in a given relief pattern, enabling gap-free or void-free filling. The SiMO.sub.x materials may be used as hardmasks or hasmask layers as well. The SiMO.sub.x materials are soluble in organic solvents and may act as via and trench filling materials for photoresist substrate or under layer materials.
[0102] The disclosed metal doped silicon-containing film-forming composition contains a novel spin-on metal doped silicon oxide precursor to generate SiMO.sub.x (M is selected form Al, Ti, Zr, Sn, Ni, W, Hf, Ta, B, Ga, Cr, Ge, In, or the like) films that possess good etch selectivity and may be removed by standard wet chemistries. The disclosed novel spin-on metal doped silicon dioxide precursor may be a monomer, oligomer or polymer.
[0103] To achieve the foregoing and other objects, as embodied and broadly described herein, the disclosed provides a process of forming a metal doped silicon oxide film, which comprises applying a solution of the metal doped silicon-containing film-forming composition onto a substrate, the metal doped silicon-containing film-forming composition may contain an alkyl metal or alkyl metalloxane polymer modified with one or more silicon-containing precursors; forming a deposited layer or a metal-containing layer or a silicon- and metal-containing layer on the substrate, the deposited layer contains inorganic and organic components; and heating the substrate in an oxygen- or nitrogen-containing atmosphere for a sufficient length of time at temperatures characterized as sufficient to remove the organic component from the deposited layer and form a metal doped silicon oxide film thereon. The metal may be selected form Al, Ti, Zr, Sn, Ni, W, Hf, Ta, B, Ga, Cr, Ge, In, or the like. Prior to applying the solution of the metal doped silicon-containing film-forming composition onto the surface, the surface of the substrate is treated to reduce its surface energy, e.g. by plasma, wet chemistry treatment, surface pre-wet, UV/O.sub.3 cleaning treatment, or the surface of the substrate contacts an adhesion promoter to increase the surface energy of the substrate.
[0104] The disclosed further provides a process of forming an aluminum doped silicon oxide film by applying a solution of an aluminum-containing film-forming composition onto a substrate, the aluminum-containing film-forming composition contains an alkyl aluminum or alkyl aluminumoxane polymer modified with one or more silicon-containing precursors; forming an aluminum-containing deposited layer on the substrate, the aluminium-containing deposited layer contains inorganic and organic components; and heating the substrate for a sufficient length of time at temperatures characterized as sufficient to remove the organic components from the aluminum-containing deposited layer and form the aluminum doped silicon oxide film. Prior to applying the solution of the aluminum-containing film-forming composition onto the surface, the surface of the substrate is treated to reduce its surface energy, e.g. by plasma, wet chemistry treatment, surface pre-wet, UV/O.sub.3 cleaning treatment, or the surface of the substrate contacts an adhesion promoter to increase the surface energy of the substrate.
[0105] The disclosed further provides a process of forming a metal doped silicon nitride or metal doped silicon oxynitride film by applying a solution of the spin-on metal-containing silicon-containing film-forming composition onto a substrate, the spin-on metal-containing silicon-containing film-forming composition includes an alkyl metal or alkyl metalloxane polymer modified with one or more silicon-containing precursors in which the one or more silicon-containing precursors contain nitrogen from an N-source listed below; forming a metal nitride or metal oxynitride deposited layer thereon, the metal nitride or metal oxynitride layer contains inorganic and organic poertions, and heating the substrate for a sufficient length of time at temperatures characterized as sufficient to remove the organic portion from the metal nitride or metal oxynitride deposited layer and form the metal doped silicon nitride film SiMN.sub.x or metal doped silicon oxynitride film SiMNxOy (x and y are integers). The metal may be selected form Al, Ti, Zr, Sn, Ni, W, Hf, Ta, B, Ga, Cr, Ge, In, or the like. Prior to applying the solution of the metal doped silicon-containing film-forming composition onto the surface, the surface of the substrate is treated to reduce its surface energy, e.g. by plasma, wet chemistry treatment, surface pre-wet, UV/O.sub.3 cleaning treatment, or the surface of the substrate contacts an adhesion promoter to increase the surface energy of the substrate.
[0106] The treating process described above includes cleaning the substrate with UV-ozone and/or HF, baking the substrate, and/or adding an adhesion layer to the substrate, etc. The adhesion layer may be formed with silane coupling reagents that may enhance adhesion of the composition or material to the substrate. In addition, aminofunctional trialkoxysilanes such as hexamethyldisilazane (HMDS), aminopropyltriethoxysilane (APTES), aminopropyltrimethoxysilane (APTMS) and (3-trimethoxysilylpropyl) diethylenetriamine (DETAS) may be employed as a surface modification molecule for generating monolayer modification on the surface of the substrate.
[0107] The disclosed relates to metal doped silicon-containing film-forming compositions or spin-on metal doped silicon-containing film-forming compositions are formed from alkyl metal, alkyl metalloxane or polymetalloxane solutions in presence of silicon precursors to form a film, which has high metal-oxide and/or metal-nitride content. The disclosed relates to a novel metal doped silicon-containing film-forming composition comprising i) at least one silicon precursor, ii) a metal precursor; and iii) a solvent. The metal precursor may be an alkyl metal, alkyl metalloxane or polyalkylmetalloxane.
[0108] The disclosed metal doped silicon-containing film-forming composition contains between approximately 0.5% w/w to approximately 99.5% w/w of the metal precursor, preferably between approximately 10% w/w to approximately 90% w/w of the metal precursor.
[0109] The disclosed at least one silicon precursor may contains nitrogen and/or oxygen.
[0110] The disclosed at least one silicon precursor may be a monomer, oligomer or polymer.
[0111] The disclosed at least one silicon precursor may be polysilanes, polysilazanes, aminosilanes, aminopolysilanes, alkoxysilanes, alkoxypolysilanes, or the like.
[0112] The disclosed at least one silicon precursor may be selected from the following compounds.
[0113] 1) A compound comprising an aminosilane having the formula:
[(R.sup.1).sub.2-mNH.sub.m].sub.nSi(R.sup.2).sub.4-n,
wherein each R.sup.1 is independently selected from alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from the group consisting of hydrogen, alkyl, vinyl, allyl, and phenyl; and n=1-4, m=0 or 1.
[0114] Exemplary compounds include Tetrakis(dimethylamino) silane and tris(dimethylamino) silane.
[0115] 2) A compound comprising an aminopolysilane with a repeating unit having the formula:
[((R.sup.1).sub.2-mNH.sub.m).sub.nSi.sub.p(R.sup.2).sub.q], [0116] wherein each R.sup.1 is independently selected from alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from the group consisting of hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0-2, m=0 or 1, p2, q=0-2; and [0117] a terminal group having the formula: [((R.sup.1).sub.2-mNH.sub.m).sub.n(R.sup.2).sub.3-nSi], wherein each R.sup.1 is independently selected from alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from the group consisting of hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0-3, m=0 or 1.
[0118] Exemplary compounds include poly(1,1-dimethylsilazane) and polyvinylsilazane.
3) A compound comprising an alkoxysilane having the formula:
[R.sup.1O].sub.nSi(R.sup.2).sub.4-n, [0119] wherein R.sup.1 is independently selected from alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from the group consisting of hydrogen, alkyl, vinyl, allyl, and phenyl; and n=1-4. Exemplary compounds include trimethoxysilane and Triisopropylsilane.
[0120] 4) A compound comprising an alkoxypolysilane with a repeating unit having the formula:
[(R.sup.1O).sub.nSi.sub.p(R.sup.2).sub.q], [0121] wherein R.sup.1 is independently selected from alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0-2, p2, q=0-2; and [0122] a terminal group having the formula: [(R.sup.1O).sub.n(R.sup.2).sub.3-nSi], [0123] wherein R.sup.1 is independently selected from alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0-3.
[0124] Exemplary compounds include ethoxy-nonamethyltetrasilane and methoxy octamethyltetrasilane.
[0125] 5) A compound comprising NH and silicon-containing molecules, including polysilazane, with a repeating unit selected from the general formulae (1a), (1b) and (1c), below and a terminal group of the formula NH.sub.2 or SiH.sub.3. Exemplary compound includes perhydropolysilazane.
##STR00003##
[0126] 6) A compound comprising a polysilane with a repeating unit having the formula:
[SiR.sup.1.sub.n], [0127] wherein each R.sup.1 is independently selected from hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0-2; and [0128] a terminal group of SiH.sub.3.
[0129] Exemplary compounds include polymethylsilane and poly(methylphenyl) silane.
[0130] 7) A compound comprising a polysilazane with a repeating unit selected from the general formulae (2a), (2b), (2c), (2d), (2e), or (2f) below and a terminal group of SiH.sub.3:
##STR00004##
[0131] U.S. Pat. No. 10,647,578B2 is related to this type of compounds. To our knowledge, this type of compounds has not been commercially available up to now.
[0132] 8) A compound comprising a polysiloxane with a repeating unit having the formula:
[O(R.sup.1O).sub.nSi(R.sup.2).sub.2-n],
wherein R.sup.1 is selected from hydrogen or alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0, 1 or 2; and [0133] a terminal group having the formula: [(R.sup.1O).sub.n(R.sup.2).sub.3-nSi], wherein R.sup.1 is independently selected from hydrogen or alkyl groups of C.sub.1 to C.sub.6; each R.sup.2 is independently selected from hydrogen, alkyl, vinyl, allyl, and phenyl; and n=0, 1, 2 or 3.
[0134] Exemplary compounds include Polymethylhydroxosiloxane, polydimethylsiloxane, poly(ethyl methyl) siloxane and Polymethylhydrosiloxane.
[0135] The amount of the disclosed at least one silicon precursor in the metal-containing silicon-containing film-forming composition is from about 0.005 to 60 mol % based on the mole of the metal precursor present, preferably from 0.01 to 40 mol %, based on the mole of the metal precursor present.
[0136] The disclosed metal precursor for the metal-containing silicon-containing film-forming composition may have a molecular weight about 200 to 1,200 dalton. The metal precursor may be cross-linked as a polymer having a high molecular weight within a short time during the heat treatment to provide excellent characteristics required for the hardmask layer such as excellent mechanical characteristics, heat resistance, chemical resistance, and etch resistance.
[0137] Here commercially available alkyl metalloxanes or polyalkylmetalloxanes may be selected as the metal precursors for forming the metal doped silicon-containing films, but are not limited to. Examplary commercially available alkyl metalloxanes or polyalkylmetalloxanes include polymethylaluminoxane, methylaluminoxane, modified methylaluminoxane, isobutylaluminoxane, or tetraisobutyldialuminoxane. The formed metal doped silicon-containing films may be SiAlO.sub.x films, where x is an integer.
[0138] In addition, commercially available alkyl metals may be selected as the metal precursors for forming the metal doped silicon-containing films, but are not limited to. Exemplary commercially available alkyl metals include trimethylaluminum, triethylaluminum, trioctylaluminum, or tri(Isobutyl)aluminum. The formed metal doped silicon-containing films may be SiAlO.sub.x films, where x and y each are an integer.
[0139] The disclosed metal doped silicon-containing film-forming compositions may comprise from 0.01% wt/wt to 80% wt/wt of a metal, preferably from 10% wt/wt to 50% wt/wt, and more preferably from 15% wt/wt to 45% wt/wt. Here, the metal is selected from Al, Ti, Zr, Sn, Ni, W, Hf, Ta, B, Ga, Cr, Ge, In, or the like.
[0140] In the disclosed metal doped silicon-containing film-forming compositions, the amount of the at least one silicon-containing precursor is from about 0.005 to 60 mol % of the metal precursor, preferably from about 0.01 to 40 mol % of the metal precursor.
[0141] The third component of the disclosed metal doped silicon-containing film-forming compositions is a solvent or a mixture of solvents which dissolves the solid components of the composition and is chemically inert with respect to the other ingredients of the composition. The solvent has different boiling points in order to adjust the metal doped silicon-containing film-forming composition's properties, such as viscosity or layer thickness. Exemplary solvents include hydrocarbons, such as pentane, hexanes, heptanes, benzene, toluene, xylene, mesitylene, other alkanes, or combinations thereof. Other suitable solvents include halohydrocarbons such as dichloromethane or chloroform; ethers such as tetrahydrofuran (THF), or methyl tert-butyl ether, and more generally aprotic solvents, such as acetonitrile, benzene, dimethylformamide, hexamethylphosphoramide, dimethyl sulfoxide, or combinations thereof. The solvent can also be an alcohol, an ether, an ester, a ketone, an amide, or a diketone. Specific non-limiting examples of suitable solvents are lower alcohols (C.sub.1-C.sub.6) such as isopropanol, n-butanol, t-butanol, 1-pentanol and 4-methyl-2-pentanol, a glycol such as ethylene glycol and propylene glycol, diketones such as diacetyl, acetylacetone, and hexane-2,5-dione, a glycol ether derivative such as 2-ethoxyethanol, 2-methoxyethanol, propylene glycol monomethyl ether (PGME), diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, dipropylene glycol dimethyl ether, propylene glycol n-propyl ether, or diethylene glycol dimethyl ether; a glycol ether ester derivative such as propylene glycol monomethyl ether acetate (PGMEA); carboxylates such as ethyl acetate, n-butyl acetate and amyl acetate; carboxylates of di-basic acids such as diethyl oxylate and diethylmalonate; dicarboxylates of glycols such as ethylene glycol diacetate and propylene glycol diacetate; and hydroxy carboxylates such as methyl lactate, ethyl lactate, ethyl glycolate, and ethyl-3-hydroxy propionate; a ketone ester such as methyl pyruvate or ethyl pyruvate; an alkoxy alcohol such as 1-methoxy-2-propanol, 2-methoxyethanol, ethoxyethanol, an alkoxycarboxylic acid ester such as methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 2-hydroxy-2-methylpropionate, or methylethoxypropionate; a ketone derivative such as methyl ethyl ketone, acetyl acetone, cyclopentanone, cyclohexanone or 2-heptanone; a ketone ether derivative such as diacetone alcohol methyl ether; a ketone alcohol derivative such as acetol or diacetone alcohol; lactones such as butyrolactone, gamma-butyrolactone and gamma-velaro lactone; aromatic solvents such as anisole, and mixtures thereof. Alternatively, the solvents may be selected from alcohols, glycols, glycol ether derivatives, glycol ether ester derivatives, aromatic solvents, saturated hydrocarbon compounds, unsaturated hydrocarbon compounds, ethers, esters, ketones or mixtures thereof.
[0142] The solvent should have a boiling point typically comprised between 50 C. and 250 C., more preferably between 70 C. and 180 C. In order to generate dense films, the solvent is selected so as to evaporate during a pre-bake step, typically performed at a temperature ranging from 40 C. to 220 C., preferably between 80 C. and 200 C. The solvent or solvent mixture selection is also guided by the need to dissolve the metal precursor and crosslinker. As such, the solvent may be a polar or a non-polar solvent, or a mixture of polar and non-polar solvent. Hydrocarbons, toluene, xylene, mesitylene are typical non-polar solvent, while tertiary amines, ethers and halocarbons are polar solvents.
[0143] In order to have good processing characteristics, metal doped silicon-containing film-forming compositions may have a suitable viscosity.
[0144] The disclosed metal doped silicon-containing film-forming compositions are particularly suitable for gap fill applications on holes, vias and trenches in semiconductor devices, including sacrificial films or leave behind films without generation of defects. The disclosed metal doped silicon-containing film-forming compositions are capable of filling structures with small openings or apertures such as a trench, typically having a critical dimension ranging from 1 nm to 10 m, preferably 10 nm to 1000 nm, and an aspect ratio ranging from approximately 1:1 to approximately 200:1, without defects, voids, delamination, cracks, and seams, as required by gap fill applications. Additionally, the disclosed metal doped silicon-containing film-forming compositions may be converted to dense, low-stress, low dry etch rate metal oxide or metal nitride films at the lowest possible temperature. The resulting films may have a uniform elemental distribution along the structure depth. Low shrinkage achieved with the disclosed metal doped silicon-containing film-forming composition, the absence of insoluble products and particles, and its ability to easily convert to a solid and dense film, make such composition or formulation particularly suitable for semiconductor gap fill applications. Shrinkage of metal doped silicon oxide or metal doped silicon nitride films is normally detrimental for semiconductor applications since it results in stress in the resulting cured film. This stress may lead to voids, pinholes, and cracks. The resulting film may also be used as a hardmask layer. A ratio of etch rate of the resulting film to a targeted film is greater than 5. Here, the resulting film is a metal doped silicon-containing film and the target film may be a silicon containing film, such as silicon oxide, silicon nitrile or silicon oxynitrile film.
[0145] The disclosed metal doped silicon-containing film-forming compositions may be applied using a spin-on coating method. Once the metal doped silicon-containing film-forming composition is deposited as a metal doped silicon-containing layer, the metal doped silicon-containing layer may be heat-treated at about 100 to about 1500 C. for about 10 seconds to 3 hours. The thickness of the metal doped silicon-containing layer may be, for example, about 50 to about 10,000 .
[0146] The substrate may be, for example low dielectric constant materials, silicon, silicon substrates, copper coated silicon wafer, copper, aluminum, polymeric resins, silicon dioxide, metals, doped silicon dioxide, silicon nitride, tantalum, polysilicon, ceramics, aluminum/copper mixtures, any of the metal nitrides such as aluminum nitride AlN; gallium arsenide and other such Group III/compounds, or a glass substrate. Silane coupling reagents may be applied to enhance adhesion of deposition materials to be deposited to the substrate. Suitable silane coupling reagents may be aminofunctional trialkoxysilanes, such as hexamethyldisilazane (HMDS), aminopropyltriethoxysilane (APTES), aminopropyltrimethoxysilane (APTMS) and (3-trimethoxysilylpropyl) diethylenetriamine (DETAS), which may be employed as a surface modification molecule for generating monolayer modification on the surface of the substrate.
[0147] The disclosed metal doped silicon-containing film-forming compositions may comprise a dissolved catalyst and/or a surfactant combined with a metal-containing oligomer or polymer having a molecular weight ranging from approximately 200 dalton to approximately 500,000 dalton. Various families of catalysts, such as a crosslinking catalyst, including amines, boranes, and organometallics, have been used to catalyze metal oligo/polymers from molecular precursors and affect the cross-linking. The crosslinking catalyst is present in an amount of 0.01 to 10 parts by weight, based on 100 parts by weight of the metal precursor.
[0148] The surfactant may be included in an amount of about 0.001 to 5% of the composition. The surfactant may be added to the disclosed metal doped silicon-containing film-forming compositions for gap filling to lower the surface tension of the composition and improve the gap-filling properties of the composition. The surfactant is preferably added in a concentration of 0.001% to 5% weight of the metal precursor in the composition.
[0149] Suitable surfactants include: i) non-ionic surfactants, such as, polyglycerol alkyl ethers, glucosyl dialkyl ethers, crown ethers, ester-linked surfactants, polyoxyethylene alkyl ethers, sorbitan esters (e.g., manufactured by Brij and Spans) and Polysorbates (e.g., manufactured by Tweens); ii) unsaturated fatty amine; iii) fluorinated surfactants; and iv) silicon-based surfactants, such as organosiloxane polymer. These surfactants may be used alone or in combination with of two or more thereof.
[0150] The disclosed metal doped silicon-containing film-forming compositions may be stored under an inert atmosphere in dried glass, plastic bottles, such as NOWPak bottles from Entegris, made of HDPE, PTFE, PE, or stainless steel canisters at temperatures ranging from approximately 0 C. to approximately room temperature. If necessary, the stainless steel canisters may be coated and/or passivated to minimize any reaction between the metal-containing composition and the canisters.
[0151] The disclosed metal doped silicon-containing film-forming compositions may also be used in coating deposition processes to form metal doped silicon oxide, metal doped silicon nitrile, metal doped silicon oxynitride, metal doped carbonitride, metal doped carboxide, metal doped oxycarbonitride films used in the electronics and optics industry. For example, the metal doped silicon oxide films are obtained from thermal treatment of a deposited film under an oxidative atmosphere, containing at least one of O.sub.2, O.sub.3, ambient air, compressed dry air, humid air, H.sub.2O, H.sub.2O.sub.2, organic peroxides, NO, N.sub.2O, NO.sub.2, CO, CO.sub.2, SO.sub.2 and combinations thereof. The disclosed metal doped silicon-containing film-forming compositions may also be used to form protective coatings or pre-ceramic materials (i.e., nitrides and oxynitrides) for use in the aerospace, automotive, military, or steel industry or any other industry requiring strong materials capable of withstanding high temperatures. Preferably the resulting film is 100% amorphous, but different crystalline phases might be present, making the film partially amorphous.
[0152] The metal doped silicon-containing film-forming compositions may be deposited or coated onto a patterned and blank substrate using techniques well known to those skilled in the art. The patterned substrate, for example, with aspect ratio ranges from 1:1 to approximately 200:1, may be any patterned substrate with features composed of vias, trenches, holes, and/or other hollow topographical features. The film thickness of the coating on patterned substrates ranges from about 5 nm to about 1000 nm. Thicker films may also be formed making multiple-stacks spin according to required thicknesses and applications. The coating may be further heated on a hot plate, hot wall chamber, cold wall chamber, tube furnace, UV curing systems, rapid thermal annealing systems or convection oven for a sufficient length of time to remove a majority of the solvent and optionally to induce curing. The baking temperature may be from about 40 C. to about 1500 C., preferably 200 C. to 800 C. for about 30 seconds to about 2 hours. For example, for metal oxide film, the composition of the film after baking contains between about 5 to about 90 wt % of total metal doped silicon-containing films.
[0153] Examples of suitable coating methods include spin coating, dip coating, spray coating, fiber spinning, extrusion, molding, casting, impregnation, roll coating, transfer coating, slit coating, etc. For usage in non-semiconductor applications, the disclosed metal doped silicon-containing film-forming compositions may also contain a filler. The coating method is preferably spin coating in order to provide suitable film thickness control and gap-fill performance.
[0154] The disclosed metal doped silicon-containing film-forming compositions may be applied directly to the center of the substrate and then spread to the entire substrate by spinning or may be applied to the entire substrate by spraying. When applied directly to the center of the substrate, the substrate may be spun to utilize centrifugal forces to evenly distribute the composition over the substrate. The viscosity of the metal doped silicon-containing film-forming compositions will contribute as to whether rotation of the substrate is necessary. Alternatively, the substrate may be dipped in the disclosed metal doped silicon-containing film-forming compositions. The resulting films may be dried at room temperature for a sufficient length of time to vaporize the solvent or volatile components of the film or dried by force-drying or baking or by the use of one or a combination of any following suitable process including thermal curing and irradiations, such as, ion irritation, electron irradiation, UV and/or visible light irradiation, etc.
[0155] The metal doped silicon-containing film-forming compositions may also be used for the formation of transparent metal oxide films suitable for optics applications. In semiconductor applications, the metal doped silicon-containing film-forming compositions may be used for forming sacrificial layers such as etching hard masks, ion implantation masks, anti-reflective coatings, tone inversion layers. Alternatively, the metal doped silicon-containing film-forming compositions may be used for forming non-sacrificial, such as gap-fill oxide layer, etch stop layers. [0156] a metal doped silicon-containing film-forming compositions is typically spun on the substrate, pre-baked at 40 C. to 250 C. to evaporate the solvent(s), and eventually converted to metal doped silicon oxide by annealing the substrate in an oxidizing atmosphere, typically containing O.sub.2, O.sub.3, H.sub.2O, H.sub.2O.sub.2, N.sub.2O, NO, at a temperature ranging from 40 to 1500 C. A multi-step annealing process in various atmospheres (oxidative or inert) may improve the oxide quality.
[0157] The process of forming the metal doped silicon oxide film further comprises one or several curing steps such as thermal curing, photon curing, microwave curing, annealing, laser treatment, etc.
Preparation of Spin Coatable Metal Doped Silicon-Containing Film-Forming Composition
[0158]
[0159] Next, a planar or patterned substrate on which the Si-containing film is to be deposited may be cleaned or prepared for the deposition process in Step 1. High purity gases and solvents are used in the preparation process. Gases are typically of semiconductor grade and free of particle contamination. For semiconductor usage, solvents should be particle free, typically less than 100 particle/ml (0.5 m particle, more preferably less than 10 particles/mL) and free of non-volatile residues that would lead to surface contamination. Semiconductor grade solvents having less than 50 ppb metal contamination (for each element, and preferably less than 5 ppb) are preferred.
[0160] In Step 1, the substrates (planar or patterned substrates) or wafers is cleaned using typical chemical cleaning agents in the art, such as, isopropanol (IPA), acetone or the like. The cleaning step is mainly to remove any contaminations on the substrates surface. One of ordinary skill in the art may determine the appropriate wafer preparation process based at least upon the substrate material and degree of cleanliness required. After the substrate cleaning preparation, the clean substrate is then transferred into a spin coater at Step 2. A liquid form or solution of the metal doped film-forming composition is dispensed onto the substrate. The wafer substrate is spun in Step 3. The spin rates may be adjusted typically from 1000 rpm to 10000 rpm. The substrate is spun until a uniform Si-containing film formed on the entire surface of the substrate. The spinning time may vary from 10 s to 3 min. One of ordinary skill in the art will recognize that this spin-on deposition process may be conducted either in a static mode (sequentially) or a dynamic mode (concurrently). This spin-on deposition is preferred to be conducted in a controlled gas environment. For example, in a controlled O.sub.2 level or H.sub.2O level. A metal doped silicon-containing film or a deposition film on the substrate is formed after this spin-on deposition.
[0161] After the metal doped silicon-containing film is formed on the substrate, the substrate is pre-baked or soft baked at Step 4 to remove any remaining volatile organic components of the metal doped silicon-containing film-forming composition and/or by-products from the spin-coating process. The pre-bake may take place in a thermal chamber or on a hot plate at a temperature ranging from approximately 40 C. to approximately 250 C. for a time period ranging from approximately 1 minute to approximately 30 minutes. After pre-bake, the Si-containing film on the substrate is then cured to a desired dielectric film, such as a SiOC film, through a hard bake process (Step 5).
[0162] In Step 5, the substrate is hardbaked to produce the desired dielectric film. The hard bake process may be carried out by thermal annealing at a temperature ranging from approximately 200 C. to approximately 1500 C. for a sufficient length of time ranging from approximately 30 minutes to approximately 4 hours. Three non-limiting options, thermal curing, UV curing or UV-thermal curing in presence of reactive gas/gases, are shown in
[0163] Briefly, the liquid form of the disclosed metal doped silicon-containing film-forming composition may be applied directly to the center of the substrate and then spread to the entire substrate by spinning or may be applied to the entire substrate by spraying. Alternatively, the substrate may be dipped in the metal doped silicon-containing film-forming composition. The resulting film may be dried at room temperature for a sufficient length of time to vaporize the solvent or volatile components of the film or dried by force-drying or baking or by the use of one or a combination of any following suitable process including thermal curing and irradiations, such as UV irradiation.
[0164] Exemplary reactive gases that introduce oxygen into the resulting film include oxygen-containing gases or an oxidizing agent, such as O.sub.2, O.sub.3, ambient air, compressed dry air, humid air, H.sub.2O, H.sub.2O.sub.2, organic peroxides such as N.sub.2O, NO, NO.sub.2, CO, CO.sub.2, SO.sub.2 and combination thereof. Under an O.sub.2/Ar, the curing temperature may range for approximately 40 C. to approximately 1500 C. Alternatively, curing may occur under a H.sub.2O.sub.2 at temperatures ranging from approximately 200 C. to approximately 800 C.
[0165] Exemplary reactive gases that introduce carbon into the resulting film include carbon-containing gases, and specifically unsaturated carbon-containing gases, such as alkenes and alkynes (ethylene, acetylene, propylene, etc.).
[0166] Exemplary reactive gases that introduce nitrogen into the film may have at least one NH bond to enable the nitriding to proceed, i.e., nitridation process. For a completely C-free film, this means that the curing gas may comprise NH.sub.3 or Hydrazines (R.sub.2NNR.sub.2, wherein R is alkyl or aryl substituents). Alternatively, C-containing N-sources may be used, but may yield some C in the film. Exemplary C-containing N-sources include substituted hydrazines, (i.e., N.sub.2R.sub.4, wherein each R is independently H or a C.sub.1-C.sub.4 hydrocarbon, provided that at least one R is H) (e.g., H.sub.2NNH.sub.2, MeHNNH.sub.2, Me.sub.2NNH.sub.2, MeHNNHMe, phenyl hydrazine, t-butyl hydrazine, 2-cyclohexyl-1,1-dimethyhydrazine, 1-tert-butyl-1,2,2-trimethylhydrazine, 1,2-diethylhydrazine, 1-(1-phenylethyl) hydrazine, 1-(2-methylphenyl) hydrazine, 1,2-bis(4-methylphenyl) hydrazine, 1,2-bis(trityl) hydrazine, 1-(1-methyl-2-phenylethyl) hydrazine, 1-Isopropylhydrazine, 1,2-Dimethylhydrazine, N,N-Dimethylhydrazine, 1-Boc-1-methylhydrazine, Tetramethylhydrazine, Ethylhydrazine, 2-Benzylidene-1,1-dimethylhydrazine, 1-Benzyl-2-methylhydrazine, 2-Hydrazinopyrazine), primary or secondary amines (i.e., H.sub.xNR.sub.3-x, wherein each R is independently a C.sub.1-C.sub.4 hydrocarbon and x is at 1 or 2) (e.g., NMeH.sub.2, NEtH.sub.2, NMe.sub.2H, NEt.sub.2H, (SiMe.sub.3).sub.2NH, n-Butylamine, Sec-Butylamine, Tert-Butylamine, Dibutylamine, Diisopropylamine, N,N-Diisopropylethylamine, N,N-dimethylethylamine, Dipropylamine, Ethylmethylamine, Hexylamine, Isobutylamine, Isopropylamine, Methylhexanamine, Pentylamine, Propylamine, cyclic amines like pyrrolidine or pyrimidine), ethylene diamines (i.e., R.sub.2NC.sub.2H.sub.4NR.sup.2 wherein each R is independently H, a C.sub.1-C.sub.4 hydrocarbon with the proviso that at least one R is H) (e.g., ethylene diamine, N,N-dimethylethylene diamine, tetramethylethylenediamine), pyrazoline, pyridine, radicals thereof, or mixtures thereof. If the desired metal doped silicon-containing film also contains oxygen, C-containing N-source may include H.sub.2NC.sub.xH.sub.2xOH, with x=1-4 hydrocarbon, such as ethanolamine. Preferably the reactive gas is NH.sub.3 or Hydrazines, radicals thereof, or mixtures thereof.
[0167] The substrate after spin-on coating or deposition is subject to thermal curing at a temperature ranging from approximately 40 C. to approximately 1,500 C., preferably from approximately 200 C. to approximately 800 C., under an inert or reactive gas. A furnace or rapid thermal processor may be used to perform the thermal curing process. Exemplary furnaces include the ThermoFisher Lindberg/Blue M tube furnace, the Thermo Scientific Thermolyne benchtop tube furnace or muffle furnace, the Inseto tabletop quartz tube furnace, the NeyTech Vulcan benchtop furnace, the Tokyo Electron TELINDY thermal processing equipment, or the ASM International ADVANCE vertical furnace. Exemplary rapid thermal processors include Solaris 100, ULVAC RTP-6, or Annealsys As-one 100.
[0168] The substrate after spin-on coating or deposition is subject to UV-curing at a wavelength ranging from approximately 172 nm to approximately 400 nm using a monochromatic or polychromatic source. Exemplary VUV- or UV-curing systems suitable to perform the UV curing include, but are not limited to, the Nordson Coolwaves 2 UV curing system, the Heraeus Noblelight Light Hammer 10 product platform, or the Unicure system from USHIO.
[0169] In another alternative, the thermal and UV curing may be performed simultaneously or sequentially. The choice of curing methods and conditions will be determined by the target metal doped silicon-containing film desired.
[0170] In another alternative, the thermal curing process may proceed in a stepwise fashion. More particularly, the thermal curing may start at a temperature ranging from approximately 40 C. to approximately 500 C. under an inert or reactive gas for a time period ranging from approximately 10 to approximately 30 minutes. The temperature may be increased by approximately 50 C. to approximately 1000 C. and maintained for an additional 10 to 30 minutes. Additional incremental temperature increases may be used, if necessary. Alternatively, the temperature may be increased using a specified ramp and then maintained at specific temperatures for a short period of time. For example, the wafer may be placed in a room temperature chamber being heated at a ramping rate of approximately 1 C./minute to approximately 70 C./minute, preferably from approximately 5 C./minute to approximately 40 C./minute, and more preferably from approximately 10 C./minute to approximately 20 C./minute. Once the temperature reaches the desired heating temperature, for example approximately 100 C. to approximately 400 C., the ramping may be stopped for a specified period of time, for example ranging from approximately 5 minutes to approximately 120 minutes. The same or a different ramping temperature rate may then be used to increase the chamber temperature to the next desired heating temperature, for example approximately 300 C. to approximately 600 C. and be maintained for another specified period of time, for example ranging from approximately 5 minutes to approximately 120 minutes. This may be repeated for again if a third heating temperature is desired, for example approximately 500 C. to approximately 1,300 C. and maintained for another specified period of time, for example ranging from approximately 5 minutes to approximately 300 minutes.
[0171] In yet another alternative, the curing may use a slow, steady heating ramp without any specified time spent at any specific temperature (e.g., approximately 0.5/minute to approximately 3 C./minute). Once curing is complete, the furnace is allowed to cool to room temperature at a cooling rate ranging from approximately 1 C./minute to approximately 100 C./minute. Applicants believe that any of these thermal curing steps may help to reduce formation of cracks and voids in the resulting film.
[0172] Additionally, shrinkage may be further reduced by controlling the O.sub.2:H.sub.2O volume ratio when an oxygen-containing atmosphere is required. Preferably, the O.sub.2:H.sub.2O ratio ranges from approximately 6:1 to approximately 2.5:1. Alternatively, shrinkage may be reduced using an H.sub.2O.sub.2:H.sub.2O atmosphere. The disclosed metal doped silicon-containing film-forming compositions may provide oxide shrinkage ranging from approximately-5% to approximately 20%, preferably from approximately 0% to approximately 10%, and more preferably from approximately 0% to approximately 5%. After curing, the resulting metal oxide film has a O:M atomic ratio ranging from approximately 1:1 to approximately 2.1:1. The C content of the resulting metal oxide film ranges from approximately 0 atomic % to approximately 30 atomic %, preferably from approximately 0 atomic % to approximately 20 atomic %. The N content of the resulting metal oxide film ranges from approximately 0 atomic % to approximately 30 atomic %, preferably from approximately 0 atomic % to approximately 20 atomic %. The Si, O, and C concentrations may be determined by X-ray photoelectron spectroscopy (XPS).
[0173] Since the resulting metal doped silicon oxide films have low volumetric shrinkage compared to other metal doped silicon oxides films formed from existing compositions or using common shrinkage controlled methods, it is harder to generate film defects, such as voids, with the disclosed methods.
[0174] The cured film is characterized using standard analytic tools. Exemplary tools include, but are not limited to, ellipsometers, X-ray photoelectron spectroscopy, X-ray reflectometry (XRR), atomic force microscopy, X-ray fluorescence, Fourier-transform infrared spectroscopy, scanning electron microscopy, secondary ion mass spectrometry (SIMS), Rutherford backscattering spectrometry (RBS), profilometer for stress analysis, Hg probe, nanoindenter, four point bending or combination thereof.
[0175] The metal doped silicon-containing films resulting from the processes discussed above may include metal doped silicon oxide, metal doped silicon nitride, metal doped silicon oxynitride, etc., in which the metal is selected from Al, Ti, Zr, Sn, Ni, W, Hf, Ta, B, Ga, Cr, Ge, In, or the like. One of ordinary skill in the art will recognize that by judicial selection of the appropriate metal doped silicon-containing film-forming composition and co-reactants, the desired resulting film may be obtained.
[0176] The metal doped silicon-containing films also exhibited excellent gap-fill in a trench having an aspect ratio of 1:1 to 200:1, preferably 1:1 to 20:1 and/or 20:1 to 200:1.
[0177] Currently, the existing method for shrinkage control is to increase the polymer crosslinking in synthesis by optimizing reaction conditions, including reaction temperature/pressure/time, catalyst activity, precursor concentration, and so on. However, it is difficult to fully optimize all of these inter-dependent conditions.
[0178] The disclosed metal doped silicon-containing film-forming compositions provide less shrinkage of metal doped silicon-containing films than existing metal doped silicon-containing film-forming compositions for semiconductor applications.
[0179] Recipes for curing of the resulting film and conversion to silicon metal oxide is also widely investigated to decrease the shrinkage, as it is believed that the shrinkage is related to the loss (volatilization) of short oligomers before they are oxidized during the curing step. As such, there is a competition between oxidation during curing and evaporation of short chain metal-containing oligomers, and the curing recipe (composition of the vapor phase, temperature ramp speed, etc.) have a significant impact on the final film shrinkage. Overall, both parameters, i.e., oxidation during curing and evaporation of short chain metal-containing oligomers, combine to yield the final shrinkage.
Wet Etch Rate Test
[0180] The baked metal doped silicon-containing film of the metal doped silicon-containing film-forming composition or residual hard mask, after oxygen plasma based pattern transfer, may be advantageously removed using a chemical stripping agent, such as acid, base, peroxide, and mixture thereof. For example, SC1 solution, 85% phosphoric acid, diluted sulfuric acid, 1-3% DHF, 10% TMAH, 10% hydrogen peroxide, aqueous alkaline peroxides and mixtures thereof are useful stripping compounds. Stripping time ranges from about 5 seconds to about 120 seconds at about room temperature to about 70 C. depending on the film curing conditions.
Dry Etch Rate Test
[0181] The etching process of the exposed part of the material layer, as described above in the method of forming a pattern, may be performed through a dry etching process using an etching gas and the etching gas may be, for example CHF.sub.3, CF.sub.4, Cl.sub.2, O.sub.2, C.sub.4F.sub.8, BCl.sub.3, and a mixed gas thereof. The process of etching is well known to those skilled in the art.
[0182] The plasma etching method includes providing a reaction chamber having a substrate disposed therein. The reaction chamber may be any enclosure or chamber within a device in which etching methods take place such as, and without limitation, reactive ion etching (RIE), capacitively coupled plasma (CCP) with single or multiple frequency RF sources, inductively coupled plasma (ICP), or microwave plasma reactors, or thermal etch or atomic layer etch (ALE) or other types of etching systems capable of selectively removing a portion of the silicon-containing film or generating active species. One of ordinary skill in the art will recognize that the different plasma reaction chamber designs provide different electron temperature control. Suitable commercially available plasma reaction chambers include but are not limited to the Applied Materials magnetically enhanced reactive ion etcher sold under the trademark eMAX or the Lam Research Dual CCP reactive ion etcher dielectric etch product family sold under the trademark 2300 Flex. The RF power and gases in such may be pulsed to control plasma properties and thereby improving the etch performance (selectivity and damage) further.
[0183] Alternatively, the plasma-treated reactant may be produced outside of the reaction chamber. The MKS Instruments' ASTRONi reactive gas generator may be used to treat the reactant prior to passage into the reaction chamber. Operated at 2.45 GHz, 7KW plasma power, and a pressure ranging from approximately 0.5 Torr to approximately 10 Torr, the reactant O.sub.2 may be decomposed into two O.Math. radicals. Preferably, the remote plasma may be generated with a power ranging from about 1 kW to about 10 KW, more preferably from about 2.5 kW to about 7.5 KW. The reaction chamber may contain one or more than one substrate. For example, the reaction chamber may contain from 1 to 200 silicon wafers having from 25.4 mm to 450 mm diameters.
EXAMPLES
[0184] The following non-limiting examples are provided to further illustrate embodiments of the invention. However, the examples are not intended to be all inclusive and are not intended to limit the scope of the inventions described herein.
[0185] The spin-coating process was conducted via a Brewer Science Cee 200X spin coater, and the formulations were filtered by Polytetrafluoroethylene (PTFE) membrane (pore size 0.2 m)discs before spin-coating step. Prepared thin films' quality from above formulations were characterized by Scanning Electron microscopy (SEM). The refractive index (n) and the extinction coefficient (k) values were measured on a J. A. Woollam M-2000 ellipsometer by J. A. Woollam. The film composition were characterized by Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) and Secondary lon Mass Spectrometry (SIMS). Thermogravimetric measurements use to measure Metal wt % were done using A Mettler Toledo Thermogravimetric Analyzer with heating from 30 C. to 500 C., at a heating rate of 10 C./min in a pure Nitrogen and compressed air atmosphere.
Example 1: Composition for Spin Coating
[0186] 0.8 g of Modified Methylaluminoxanes (MMAO) and 3.5 g perhydropolysilazane in mesitylene was mixed at room temperature. This solution was stirred and maintained at constant temperature of 25-30 C. for 2 hours, and then filtered using a 0.2 m PTFE filter. The spin coating was done on a Silicon coupon wafer at a 1000-3000 rpm speed with thickness ranged from 50-300 nm. The film was then cured under H.sub.2O.sub.2/N.sub.2 flow in tube furnace, the curing temperature ranged from 200-800 C. Film composition analysis from XPS: Si: 42.4 wt %; O: 50.8 wt %; Al: 5 wt %; C: 0.7 wt %; and N: 1.4 wt %. There was no detectable SiH group by FTIR spectrum.
Example 2: Composition for Spin Coating
[0187] 3.5 g of modified methylaluminoxanes (MMAO) and 1.05 g poly(diethoxysiloxane) in mesitylene was mixed at room temperature. This solution was stirred and maintained at constant temperature of 25-30 C. for 2 hours, and then filtered using a 0.2 m PTFE filter. The spin coating was done on a Silicon coupon wafer at a 1000-3000 rpm speed with thickness ranged from 50-300 nm. The film was then cured under H.sub.2O.sub.2/N.sub.2 flow in tube furnace, the curing temperature ranged from 200-800 C. Film composition analysis from XPS: Si: 23.5 wt %; O: 47.3 wt %; Al: 25.4 wt %; C: 1.7 wt %; and N: 2.1 wt %. There was no detectable SiH group by FTIR spectrum.
Example 3: Spin Coating Process Trench Filling
[0188] The spin coating of the formulation examples was done by dispensing a solution of each formulation onto the center of a substrate (e.g. silicon wafer) and then spinning the substrate at high speed (typically between 1000 to 3000 rpm). The formulation of Example 1 was diluted in mesitylene and was spin-coated on a deep via substrate patterned wafer with trench sizes of 100 nm to 1000 nm (depth) 10 nm to 100 nm (width) and line/space (L/S) 1:1. The coated wafer was subsequently cured at 200 C. to 800 C. under oxidizing environment for a certain period of time. The solid content in the formulation could be adjusted to achieve target overburden thickness on patterned wafer. The trench filling performance was evaluated by the cross-section scanning electron microscopy (XSEM) result.
Example 4: Dry Etch Rate for Coatings Prepared with Formulation of Examples 1 and 2 using C.SUB.4.F.SUB.8 .as Etch Gases
[0189] Experiments were carried out with commercial LAM tool 4520XLe 200 mm (CCP dual frequency plasma) or alternatively with commercial AMEC 300 mm Primo SSC HD-RIE etcher. Planar wafers were purchased from Advantive Tech. Planar wafers tested are different substrates below. [0190] 2 m PECVD TEOS (SiO) on Si substrate; [0191] 2 m PECVD Si.sub.3N.sub.4 (SiN) on Si substrate; [0192] 300 nm LPCVD polysilicon (poly-Si) on Si substrate; and [0193] 90 nm Al.sub.2O.sub.3 (ALD) formed by precursors TMA and H.sub.2O.
[0194] For planar tests, etch rate (ER) were measured using an ellipsometer and/or scanning electron microscope (SEM) by measuring the change in etch thickness as a function of etching time. The etching experiment were performed on four 1.5 x1.5 cm2 coupons having four different substrate materials including SiO, SiN, and p-Si, listed above. The coupons are placed on 200 or 300 mm diameter carrier wafer and held in contact by using silicon oil or thermal paste. Alternatively, double sided carbon tape may have been used to stick coupons on carrier wafer.
[0195] Etching tests were performed at a pressure of 30 mTorr, source power of 750 W (27 MHz), bias power of 1500 W (2 MHZ), and temperature 20 C. The feed mixture contains 250 sccm of Ar, 15 sccm of etch gas. Table 1 lists the relative bulk etch rate of metal oxide samples vs. SiO.sub.x at various baking temperatures in C.sub.4F.sub.8 gas.
TABLE-US-00001 TABLE 1 Relative etch rate (C.sub.4F.sub.8) Materials Bake conditions Selectivity SiO/SiAlO.sub.x SiAlO.sub.x-1 @100 C., <1 h, under dry air ~1.7 SiAlO.sub.x-2 @350 C., <1 h, under dry air ~4.5 SiAlO.sub.x-3 @600 C., <1 h, under N.sub.2 ~5.6 SiAlO.sub.x-4 @350 C., <1 h, under H.sub.2O.sub.2 ~2.6 SiAlO.sub.x-5 @600 C., <1 h, under N.sub.2 ~2.1
Example 5: Wet Etch Rate Test
[0196] Experiments were carried out in diluted HF solution (100:0.7). Reference planar wafer with SiO.sub.2 layer were purchased from Advantive Tech: 80 nm thermal SiO.sub.2 (900 C.) on Si substrate. Table 2 lists the wet etch rate of metal oxide samples vs. SiO.sub.x at various baking temperatures in different gases.
TABLE-US-00002 TABLE 2 Wet etch rate Selectivity Materials Bake conditions SiO/SiAlO.sub.x SiAlO.sub.x-4 @350 C., <1 h, under H.sub.2O.sub.2 >15 nm/min SiAlO.sub.x-5 @600 C., <1 h, under N.sub.2 >67 nm/min Thermal SiO.sub.2 N/A Etch rate: 1.8-2 nm/min
[0197] It will be understood that many additional changes in the details, materials, steps, and arrangement of parts, which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims. Thus, the present invention is not intended to be limited to the specific embodiments in the examples given above and/or the attached drawings.
[0198] While embodiments of this invention have been shown and described, modifications thereof may be made by one skilled in the art without departing from the spirit or teaching of this invention. The embodiments described herein are exemplary only and not limiting. Many variations and modifications of the composition and method are possible and within the scope of the invention. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims which follow, the scope of which shall include all equivalents of the subject matter of the claims.