DEPOSITION OF IODINE-CONTAINING CARBON FILMS
20230193460 · 2023-06-22
Inventors
- Phong NGUYEN (Newark, TX, US)
- Fabrizio Marchegiani (Newark, DE)
- Nathan Stafford (Damascus, OR, US)
- Xiangyu Guo (Bear, DE, US)
Cpc classification
C23C16/45534
CHEMISTRY; METALLURGY
C23C16/45536
CHEMISTRY; METALLURGY
C23C16/45553
CHEMISTRY; METALLURGY
International classification
C23C16/455
CHEMISTRY; METALLURGY
Abstract
A method for depositing an iodine-containing film on a substrate material comprises: exposing the substrate material to a vapor of a film-forming composition comprising an iodine-containing precursor having a formula of C.sub.aH.sub.xI.sub.yF.sub.z, wherein a=1-10, x≥0, y≥1, z≥0, x+y+z=a, 2a or 2a+2; provided that when a=1, x=2 and z=0, y is not equal to 2, and depositing the iodine-containing film formed by the iodine-containing precursor on the substrate material through a vapor deposition method. The method further comprises exposing the substrate material to a vapor of a co-reactant nitrogen-containing molecule having a general formula C.sub.xH.sub.yF.sub.zNH, where x=1-6, y=0-13, z=0-13, and a=1-2 or C.sub.xH.sub.yF.sub.zN—R.sup.1, where x=1-6, y=0-13, z=0-13, and R.sup.1 is a C.sub.1-C.sub.5 hydrocarbon.
Claims
1. A method for depositing an iodine-containing film on a substrate material, the method comprising: a) exposing the substrate material to a vapor of a film-forming composition comprising an iodine-containing precursor having a formula of C.sub.aH.sub.xI.sub.yF.sub.z, wherein a=1-10, x≥0, y≥1, z≥0, x+y+z=a, 2a or 2a+2; provided that when a=1, x=2 and z=0, y is not equal to 2; and b) depositing the iodine-containing film formed by the iodine-containing precursor on the substrate material through a vapor deposition method.
2. The method of claim 1, wherein the step b) comprising the step of modifying the substrate material or doping iodine from the iodine-containing precursor into the substrate material
3. The method of claim 1, wherein, additionally, when a=0 and x=0, the iodine-containing precursors include I.sub.2, IF.sub.3, IF.sub.5, and IF.sub.7; when a=0, z=0, the iodine-containing precursors include HI.
4. The method of claim 1, further comprising exposing the substrate material to a vapor of a co-reactant sequentially or simultaneously with the step a).
5. The method of claim 4, wherein the co-reactant is a nitrogen-containing molecule having a general formula C.sub.xH.sub.yF.sub.zNH.sub.a where x=1-6, y=0-13, z=0-13, and a=1-2 or C.sub.xH.sub.yF.sub.zN—R.sup.1, where x=1-6, y=0-13, z=0-13, and R.sup.1 is a C.sub.1-C.sub.5 hydrocarbon.
6. The method of claim 5, wherein the nitrogen-containing molecule is selected from N.sub.2, NH.sub.3, hydrazine N.sub.2H.sub.4, dimethylhydrazine C.sub.2H.sub.8N.sub.2, guanidine CH.sub.5N.sub.3, primary and secondary amine or imino, or contains N≡C—R.sup.1, wherein R.sup.1 has the formula H.sub.aF.sub.bC.sub.c, where a=1-11, b=1-11, and c=1-5; (N≡C—)—(R.sup.2)—(—C≡N), wherein R.sup.2 has the formula H.sub.mF.sub.nC.sub.o with m=0, n=1-11, and o=1-5; and R.sup.3.sub.x[—C═N(R.sup.4.sub.z)].sub.y, wherein x=1-2, y=1-2, z=0-1, x+z=1-3, and R.sup.3 and R.sup.4 each independently has the formula H.sub.eF.sub.fC.sub.g with e=0-11 f=0-11, and g=0-5.
7. The method of claim 5, wherein the nitrogen-containing molecule is C.sub.3HF.sub.4N.
8. The method of claim 4, wherein the co-reactant is an oxidizer selected from O.sub.2, O.sub.3, CO, CO.sub.2, NO, N.sub.2O, NO.sub.2, H.sub.2O, H.sub.2O.sub.2, COS, SO.sub.2, compressed air or combinations thereof.
9. The method of claim 4, wherein the co -.reactant is an inert gas selected from He, Ar, N.sub.2, Xe, Kr, Ne, or combinations thereof.
10. The method of claim 4, wherein the co-reactant is an additive gas selected from CF.sub.4, CH.sub.3F, C.sub.2F.sub.6, C.sub.3F.sub.8, C.sub.2HF.sub.6, C.sub.5F.sub.8, C.sub.6F.sub.6, C.sub.4F.sub.6, C.sub.5F.sub.8, C.sub.1 to C.sub.10 saturated or unsaturated linear, branched, cyclic hydrofluorocarbons, such as C.sub.4H.sub.2F.sub.6, C.sub.3H.sub.2F.sub.6, CHF.sub.3, CH.sub.2F.sub.2, or combinations thereof, an iodine-containing additive, other than C.sub.aH.sub.xI.sub.yF.sub.z, having a formula C.sub.bH.sub.mI.sub.nF.sub.o, wherein b=1-10, m≥0, n≥1, o≥0, m+n+o=b, 2b or 2b+2; provided that when a=1, x=2 and z=0, y is not equal to 2, provided that when b=0 and m=0, the iodine-containing additives include I.sub.2, IF.sub.3, IF.sub.5, and IF.sub.7; when b=0, o=0, the iodine-containing additives include HI.
11. The method of claim 1, wherein the iodine-containing precursor is selected from the group consisting of CH.sub.3I and C.sub.2H.sub.2F.sub.3I.
12. The method of claim 1, wherein the vapor deposition method is a thermal or plasma deposition process.
13. The method of claim 1, wherein an iodine atomic concentration in the iodine-containing film ranges from approximately 0.01% to approximately 50% with a uniform concentration through the iodine-containing film.
14. The method of claim 2, wherein an iodine atomic concentration in the substrate material ranges from approximately 0.01% to approximately 50%. 15, The method of claim 1, wherein a deposition temperature ranges from −110° C. to 1100° C.
16. A method for depositing an iodine-containing and nitrogen-containing film on a substrate material, the method comprising: a) sequentially or simultaneously exposing the substrate material to a vapor of a film-forming composition and a vapor of a nitrogen-containing molecule, wherein the film-forming composition comprises an iodine-containing precursor having a formula of C.sub.xH.sub.xI.sub.yF.sub.z, wherein a=1-10, x≥0, y≥1, z≥0, x+y+z=a, 2a or 2a+2, provided that when a=1, x=2 and z=0, y is not equal to 2, wherein the nitrogen-containing molecule has a general formula C.sub.mH.sub.nF.sub.oNH.sub.b or C.sub.xH.sub.yF.sub.zN—R.sup.1 where m=1-6, n=0-13, o=0-13, b=1-2, and R.sup.1 is a C.sub.1-C.sub.5 hydrocarbon; and b) depositing the iodine-containing film formed by the iodine-containing precursor on the substrate material through a thermal or plasma method.
17. The method of claim 16, wherein the step b) comprises modifying the substrate material or doping iodine into the substrate material,
18. The method of claim 16, wherein the iodine-containing precursor is selected from the group consisting of CH.sub.3I and C.sub.2H.sub.2F.sub.3I.
19. The method of claim 16, wherein the nitrogen-containing molecule is C.sub.3HF.sub.4N.
20. A method for depositing an iodine-containing film on the substrate material, the method comprising; a) sequentially or simultaneously exposing the substrate material to a vapor of CH.sub.3I or C.sub.2H.sub.2F.sub.3I and a vapor of C.sub.3HF.sub.4N; and b) depositing a layer of iodine-containing polymer formed by CH.sub.3I or C.sub.2H.sub.2F.sub.3I on the substrate material through a thermal or plasma method, wherein the step b) comprises modifying the substrate material or doping iodine into the substrate material.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0172] 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:
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DESCRIPTION OF PREFERRED EMBODIMENTS
[0187] Disclosed are iodine-containing film forming compositions comprising iodine-containing precursors that may contain or may not contain halogens other than iodine, and methods of using the iodine-containing film forming compositions to deposit a thin film on a substrate material such as a carbon-containing material (e.g., amorphous carbon material), modify the surface of the substrate material and/or dope iodine into the substrate material through a vapor deposition method, such as a thermal or plasma deposition process, a plasma equipment such as an etcher (e.g., a LAM tool etcher), a plasma enhanced ALD or CVD and/or a thermal ALD or CVD. In some embodiments, a nitrogen-containing molecule may be used as a co-reactant to enhance the deposition of the iodine-containing film, the modification of the substrate material and the doping of the iodine into the substrate material.
[0188] The substrate material or the modified and/or doped substrate material having a deposited iodine-containing thin film thereon may be used as an iodinated carbon film for etching processes. The deposited iodine-containing thin film may be located above the substrate material layer to be etched. Exemplary substrate material may include carbon-containing materials. Exemplary carbon-containing materials may include amorphous carbon (a-C), or boron and metal doped a-C or silicon doped a-C, or the like.
[0189] The disclosed method provides not only a new/novel chemistry to deposit an iodine-containing film on a carbon material surface, but also a method to enhance iodine concentration in the carbon material. Such iodine-modified layer may be utilized in various applications in semiconductor fabricating device. The disclosed iodine-containing precursors and the disclosed film forming compositions may be used for forming high-speed, high sensitivity semiconductor films, e.g., in CMOS systems, DARM memory, 3D NAND channel or in photodetectors.
[0190] The disclosed iodine-containing precursors and the disclosed film forming compositions are suitable to deposit corresponding element-containing films and their deposition method to synthesize the corresponding element-containing film. The deposited films using the disclosed method may be deposited uniformly on flat wafers or on patterned wafers, or in a “gap-fill” or “bottom-up gap-fill” approach.
[0191] The disclosed method provides a novel chemistry to modify surface of carbon materials with iodine-containing molecules or to deposit a thin layer of iodine-containing polymer using a combination of iodine molecule with nitrogen-containing molecules, and iodine molecule with oxygen containing molecules.
[0192] The disclosed iodine-containing precursors have a formula of C.sub.aH.sub.xI.sub.yF.sub.z, wherein a=1-10, x≥0, y≥1, z≥0, x+y+z=a; 2a or 2a+2; provided that when a=1, x=2 and z=0, y is not equal to 2; provided that when a=0 and x=0, the iodine-containing precursors include I.sub.2, IF.sub.3, IF.sub.5, and IF.sub.7; provided that when a=0, z=0, the iodine-containing precursors include HI. Two examples of the disclosed iodine-containing precursors are CH.sub.3I and C.sub.2H.sub.2F.sub.3I shown in Table 1.
TABLE-US-00001 TABLE 1 Molecule Molecule Molecule name formula structure CAS No. B.P. (° C.) Iodomethane CH.sub.3I
[0193] The disclosed film forming compositions may include the nitrogen-containing molecules, such as N-containing hydroflurocarbons (HFC) and/or fluorocarbons. The addition of nitrogen in the deposition process may increase the iodine composition of the deposited film and the iodine concentration doped into the underneath layer such as carbon-containing material as well as play a beneficial role in the EUV process. The nitrogen may be in a form of N.sub.2, NH.sub.3 or in a form of hydrocarbon, hydrofluorocarbon molecule where the nitrogen is bonded to carbon and the nitrogen functional group is —C≡N, C═N, or —C—N—R where R is carbon or hydrogen (—NH or —NH.sub.2 group), or the nitrogen is within a ring structure bonded to carbon or another nitrogen molecule. Among any of these molecules, the iodine may be contained within the molecule as well. The elements containing in the thin film deposited with the disclosed method using a plasma source are not limited to C, I, N or C, I, O on a substrate where the substrate is carbon or silicon containing material. The thin film may be deposited using either a gas containing C, I, N or C, I, O, but not limited to, or using a combination of an iodine containing gas and nitrogen or oxygen containing gas.
[0194] The nitrogen-containing molecules used in the disclosed methods may have a general formula C.sub.xH.sub.yF.sub.zNH.sub.a where x=1-6, y=0-13, z=0-13, and a=1-2 or C.sub.xH.sub.yF.sub.zN—R.sup.1 where R.sup.1 may be C.sub.1-C.sub.5 hydrocarbon. The nitrogen-containing molecules used in the disclosed methods may contain N≡C—R.sup.1, wherein R.sup.1 has the formula H.sub.aF.sub.bC.sub.c, where a=1-11, b=1-11, and c=1-5; (N≡C—)—(R.sup.2)—(—C≡N), wherein R.sup.2 has the formula H.sub.mF.sub.nC.sub.o with m=0, n=1-11, and o=1-5; and R.sup.3.sub.x[—C═N(R.sup.4.sub.z)].sub.y, wherein x=1-2, y=1-2, z=0-1, x+z=1-3, and R.sup.3 and R.sup.4 each independently has the formula H.sub.eF.sub.fC.sub.g with e=0-11, f=0-11, and g=0-5. Examples of the disclosed nitrogen-containing molecules listed in Table 2. The nitrogen-containing molecule used in the disclosed method may be 2,3,3,3-Tetrafluoropropanenitrile, C.sub.3HF.sub.4N.
TABLE-US-00002 TABLE 2 Molecule Molecule Molecule name formula structure CAS No. B.P. (° C.) 2,3,3,3- Tetrafluoropropanenitrile C.sub.3HF.sub.4N
[0195] Additionally, the nitrogen-containing molecules used in the disclosed methods may be N.sub.2, NH.sub.3, hydrazine N.sub.2H.sub.4, dimethylhydrazine C.sub.2H.sub.8N.sub.2, guanidine CH.sub.5N.sub.3, primary and secondary amine e.g, ethylene diamine and imino e.g. diiminopyridine etc.
[0196] The oxygen containing molecules used in the disclosed methods include H.sub.pOC—R.sup.1, where p could be p=0, or 1, wherein R.sup.1 has the formula H.sub.aF.sub.bC.sub.cO.sub.o and a=1-11, b=1-11, o=1-2, and c=1-5; (R.sup.2—)—(O)—(—R.sup.3), wherein R.sup.2 has the formula H.sub.eF.sub.fC.sub.gO.sub.h and e=1-11, f=1-11, o=1-2 and g=1-5; R.sup.3 has the formula H.sub.mF.sub.nC.sub.oO.sub.p with m=0, n=1-11, p=1-2 and o=1-5; and R.sup.4.sub.x[—C═O(R.sup.5.sub.z)].sub.y, wherein x=1-2, y=1-2, z=0-1, x+z=1-3, and R.sup.4 and R.sup.5 each independently has the formula H.sub.uF.sub.vC.sub.wO.sub.z with u=0-11, v=0-11, z=1-2 and w=0-5. Examples of the disclosed oxygen-containing molecules include COF.sub.2, C.sub.2O.sub.2F.sub.2, (CF.sub.3).sub.3COH, and the like.
[0197] In general, it is required to form a predetermined material pattern on a semiconductor wafer or glass substrate in the manufacture of integrated circuit semiconductor devices, liquid crystal displays, plasma displays, etc. The formation of the predetermined material pattern involves coating an iodinated carbon layer on a material layer deposited on the semiconductor wafer or glass substrate, forming an iodinated carbon layer pattern through exposure, and etching the material layer into the predetermined material pattern using the iodinated carbon layer pattern as an etching layer.
[0198] In some embodiments, a substrate 100 may include a stack of multiple layers thereon as shown in
[0199] As discussed above, in order to enhance EUV absorption of the deposited film or layer using the disclosed method during patterning process such as resist less lithography, iodine element could be bind/doped to an a-C film or a carbon material or a carbon matrix. Such formed iodine-containing polymer and/or amorphous carbon may be utilized to enhance critical dimension of semiconductor features.
[0200] During a plasma process, the disclosed iodine-containing gases or precursors may be generated into the following forms: 1) iodine ion (I.sup.+, I.sup.−); 2) iodine radical (I.Math.); 3) iodine-containing polymeric ion (.sup.+C.sub.xH.sub.yI.sub.zF.sub.d, .sup.−C.sub.xH.sub.yI.sub.zF.sub.d; and 4) iodine-containing polymeric radicals (.Math.C.sub.xH.sub.yI.sub.zF.sub.d). The first and third form of iodine may be deposited onto the carbon surface through a control of bias power. In addition, these chemical forms will deposit as a polymer layer that could enhance EUV absorption of layer during a patterning process. Furthermore, these chemical forms could have iodine penetrate into the carbon-containing material to modify the carbon-containing material or modify the surface of the carbon-containing material and dope iodine into the carbon-containing material as well.
[0201] Also the disclosed are methods for forming the iodine-containing polymer on a carbon-containing material using a plasma deposition process. Applicants believe that the disclosed film forming compositions are suitable for a thermal or plasma deposition process, such as, thermal ALD and PEALED, thermally CVD and PECVD, plasma equipment such as a LAM tool etcher. The disclosed methods may be useful in the manufacture of semiconductor, photovoltaic, LCD-TFT, flat panel type devices.
[0202] With the disclosed method, an iodine atomic concentration in the iodine-containing polymer or film deposited on the carbon-containing material or the surface of the carbon-containing material may range from approximately 0.01% to approximately 99.9%, preferably, from approximately 0.01% to approximately 50%, more preferably, from approximately 7% to approximately 30%. Furthermore, the iodine atomic concentration in the iodine-containing polymer deposited on the carbon-containing material with the disclosed method maintains a uniform concentration through the iodine-containing polymer or film. With the disclosed method, an iodine atomic concentration doped in the carbon-containing material may range from approximately 0.01% to approximately 99.9%, preferably, from approximately 0.01% to approximately 50%, more preferably, from approximately 7% to approximately 30%.
[0203] The plasma method includes providing a plasma reaction chamber having a substrate disposed therein. The plasma reaction chamber may be any enclosure or chamber within a device in which etching methods take place such as, and without limitation, LAM tool etcher, Reactive Ion Etching (RIE), Dual Capacitively Coupled Plasma (CCP) with single or multiple frequency RF sources, Inductively Coupled Plasma (ICP), or Microwave Plasma reactors, cryogenic-RIE, or other types of etching systems capable of selectively removing a portion of the Si containing layer or generating active species. The etch chamber may also have a temperature controlled stage where the temperature may be controlled from −110° C. to 1100° C. One of ordinary skill in the art will recognize that the different plasma reaction chamber designs provide different electron temperature control.
[0204] The disclosed iodine-containing film forming compositions are provided at greater than 95% v/v purity, preferably at greater than 99.99% v/v purity, and more preferably at greater than 99.999% v/v purity. The disclosed Iodine-containing film forming compositions contain less than 5% v/v, preferably less than 1% v/v, more preferably less than 0.1% v/v, and even more preferably less than 0.01% v/v of any of its analogs or other reaction products. This embodiment may provide better process repeatability. This embodiment may be produced by purification (e.g., distillation, sublimation, chromatography, etc.) of the Iodine-containing film forming composition. The disclosed iodine-containing compounds contain less than 5% by volume trace gas impurities, with less than 150 ppm by volume of impurity gases, such as H.sub.2O and/or CO.sub.2, contained in said trace gaseous impurities. Preferably, the water content in the plasma etching gas is less than 20 ppm by weight. The purified product may be produced by distillation and/or passing the gas or liquid through a suitable adsorbent, such as a 4 Å molecular sieve.
[0205] The disclosed iodine-containing film forming compositions contain less than 10% v/v, preferably less than 1% v/v, more preferably less than 0.1% v/v, and even more preferably less than 0.01% v/v of any of its isomers, which may be purified by distillation of the gas or liquid to remove isomers and may provide better process repeatability.
[0206] Alternatively, the disclosed iodine-containing film forming compositions may contain between 0.01% v/v and 99.99% v/v of its isomers, particularly when the isomer mixture provides improved process parameters or if isolation of the target isomer is too difficult or expensive. The mixture of isomers may also reduce the need for two or more gas lines to the reaction chamber.
[0207] Some of the disclosed iodine-containing film forming compositions are gaseous at room temperature and atmospheric pressure. For the non-gaseous (i.e., liquid or solid) compounds, their gas form may be produced by vaporizing the compounds through a conventional vaporization step, such as direct vaporization or by bubbling with inert gas (such as Ar, He, Kr, Xe, Ne), The non-gaseous compounds may be fed in liquid state to a vaporizer where it is vaporized before it is introduced into a reaction chamber.
[0208] The disclosed iodine-containing film forming compositions may be supplied either in neat form or in a blend with a suitable solvent, such as hydrocarbon such as ethyl benzene, xylene, mesitylene, decalin, decane, dodecane, alcohol such as methanol, ethanol etc. The disclosed precursors may be present in varying concentrations in the solvent.
[0209] The neat or blended iodine-containing film forming compositions are introduced into a reactor in a vapor form by conventional means, such as tubing and/or flow meters. The vapor form may be produced by vaporizing the neat or blended composition through a conventional vaporization step such as direct vaporization, distillation, by bubbling, or by using a sublimator. The neat or blended composition may be fed in liquid state to a vaporizer where it is vaporized before it is introduced into the reactor. Alternatively, the neat or blended composition may be vaporized by passing a carrier gas into a container containing the composition by bubbling the carrier gas into the composition. The carrier gas may include, but is not limited to, Ar, He, Ne, Kr, Xe and mixtures thereof. Bubbling with a carrier gas may also remove any dissolved oxygen present in the neat or blended composition. The carrier gas and composition are then introduced into the reactor as a vapor.
[0210] If necessary, the container containing the disclosed film forming composition may be heated to a temperature that permits the composition to have a sufficient vapor pressure. The container may be maintained at temperatures in the range of, for example, approximately 0° C. to approximately 250° C. Those skilled in the art recognize that the temperature of the container may be adjusted in a known manner to control the amount of precursor vaporized.
[0211] The reactor contains one or more substrates (including but not limited to, carbon layers, Si or Si-containing layers) onto which the iodine-containing films will be deposited. A substrate is generally defined as the material on which a process is conducted. The substrates may be any suitable substrate used in semiconductor, photovoltaic, fiat panel, LCD-TFT device manufacturing. Examples of suitable substrates include wafers, such as silicon, silica, glass, GaAs wafers. The wafer may have one or more layers of differing materials deposited on it from a previous manufacturing step, as shown in
[0212] The substrate final application is not limited to the present invention, but this technology may find particular benefits for the following types of substrates: silicon wafers, glass wafers and panels, beads, powders and nano-powders, monolithic porous media, printed circuit board, plastic sheets, etc. Exemplary powder substrates include a powder used in rechargeable battery technology. A non-limiting number of powder materials include NMC (Lithium Nickel Manganese Cobalt Oxide), LCO (Lithium Cobalt Oxide), LFP (Lithium Iron Phosphate), and other battery cathode materials.
[0213] The temperature and the pressure within the reaction chamber are held at conditions suitable for vapor depositions, such as ALD and CVD. In other words, after introduction of the vaporized disclosed film forming composition into the reaction chamber, conditions within the reaction chamber are such that at least part of the precursor is deposited onto the substrate to form a layer. For instance, the pressure in the reactor or the deposition pressure may be held between about 10.sup.−3 torr and about 1000 torr preferably between about 1 mTorr and 760 torr, as required per the deposition parameters. Likewise, the temperature in the reactor or the deposition temperature may be held between about −110° C. and about 1100° C., preferably between about −110° C. and about 500° C. One of ordinary skill in the art will recognize that “at least part of the precursor is deposited” means that some all of the precursor reacts with adheres to the substrate.
[0214] The temperature to achieve optimal film growth may be controlled by either controlling the temperature of the substrate holder. Devices used to heat or cool the substrate are known in the art. The substrate is heated or cooled to a sufficient temperature to obtain the desired film at a sufficient deposition rate and with desired physical state and composition. A non-limiting exemplary temperature range to which the substrate may be changed includes from approximately −110° C. to approximately 1100° C.
[0215] Alternatively, the substrate may be heated to a sufficient temperature to obtain the desired Iodine-containing film at a sufficient deposition rate and with desired physical state and composition. A non-limiting exemplary temperature range to which the substrate may be heated or cooled includes being heated from room temperature to approximately 1100° C. and being cooled from room temperature to approximately to −110° C.
[0216] Depending on the particular process parameters, deposition may take place for a varying length of time. Generally, deposition may be allowed to continue as long as desired necessary to produce a film with the necessary properties. Typical film thicknesses may vary from several angstroms to several hundreds of microns, preferably from 0.1 nm to thousands of nm, more preferably, from monolayer (˜0.1 nm) to 1 nm, that is from 0.1 to 1 nm, depending on the specific deposition process. The deposition process may also be performed as many times as necessary to obtain the desired thickness of the film.
[0217] The disclosed methods for depositing an iodine-containing layer on a carbon-containing material substrate include: placing the substrate in a reactor, delivering into the reactor a vapor of the disclosed Iodine-containing film forming composition, and contacting/adsorbing the vapor with the surface of the substrate (and typically directing the vapor to the substrate) to form an Iodine-containing layer on the surface of the substrate through a vapor deposition method, wherein the step of contacting/adsorbing modifies the carbon-containing material and/or doping iodine into the carbon-containing material. Alternatively, the disclosed methods for depositing an iodine-containing layer on a carbon-containing material substrate include: placing the substrate in a reactor, sequentially or simultaneously delivering into the reactor a vapor of the disclosed Iodine-containing film forming composition and a vapor of a nitrogen-containing molecule, and contacting/adsorbing the vapors with a surface of the substrate (and typically directing the vapor to the substrate) to form an Iodine-containing layer on the surface of the substrate through a vapor deposition method, wherein the step of contacting/adsorbing modifies the carbon-containing material substrate and/or doping iodine into the carbon-containing material. Alternatively, the disclosed methods for depositing an iodine-containing layer on a carbon-containing material substrate include: exposing the substrate to a vapor of the disclosed Iodine-containing film forming composition, and depositing/contacting/adsorbing an Iodine-containing layer on the surface of the substrate through a vapor deposition method, wherein the step of contacting/adsorbing modifies the carbon-containing material substrate and/or doping iodine into the carbon-containing material. Alternatively, the disclosed methods for depositing an iodine-containing layer on a carbon-containing material substrate: sequentially or simultaneously exposing the substrate to a vapor of the disclosed Iodine-containing film forming composition and a vapor of a nitrogen-containing molecule, and depositing/contacting/adsorbing an Iodine-containing layer on the surface of the substrate through a vapor deposition method, wherein the step of contacting/adsorbing modifies the carbon-containing material substrate and/or doping iodine into the carbon-containing material,
[0218] The vapor of the iodine-containing film forming composition is generated and then introduced into a reaction chamber containing a substrate. The temperature and the pressure in the reaction chamber and the temperature of the substrate are held at conditions suitable for vapor deposition of at least part of the disclosed Iodine-containing precursor onto the substrate. In other words, after introduction of the vaporized composition into the reaction chamber, conditions within the reaction chamber are adjusted such that at least part of the precursor is deposited onto the substrate to form the Iodine-containing layer, One of ordinary skill in the art will recognize that “at least part of the precursor is deposited” means that some or all of the precursor reacts with or adheres to the substrate.
[0219] Herein, a co-reactant may also be used to help in the formation of the Iodine-containing layer and the doping of iodine.
[0220] The co-reactant may be the nitrogen-containing molecule stated above and listed in Table 2.
[0221] The co-reactant may be an oxidizer such as O.sub.2, O.sub.3, CO, CO.sub.2, NO, N.sub.2O, NO.sub.2, H.sub.2O, H.sub.2O.sub.2, COS, SO.sub.2 and combinations thereof. The disclosed film forming composition and the oxidizer may be mixed together prior to introduction into the reaction chamber. Alternatively, the oxidizer may be introduced continuously into the chamber and the film forming composition may be introduced into the chamber in pulses, vice versa. The oxidizer may comprise between approximately 0.01% v/v to approximately 99.99% v/v of the mixture introduced into the chamber (with 99.99% v/v representing introduction of almost pure oxidizer for the continuous introduction alternative).
[0222] The co-reactant may be an additive gas or an additive chemical. The additive gas may be a fluorocarbon and/or hydrofluorocarbon. Exemplary disclosed fluorocarbons and/or hydrofluorocarbons used for the additives include CF.sub.4, CH.sub.3F, C.sub.2F.sub.6, C.sub.3F.sub.6, C.sub.2HF.sub.5, C.sub.5F.sub.8, C.sub.6F.sub.6, C.sub.4F.sub.6, C.sub.4F.sub.3, C.sub.1 to C.sub.10 saturated or unsaturated linear, branched, cyclic hydrofluorocarbons, such as C.sub.4H.sub.2F.sub.5, CHF.sub.3, CH.sub.2F.sub.2, or combinations thereof. The additive gas may also be an iodine-containing molecules same as the iodine-containing precursor having a formula C.sub.aH.sub.xI.sub.yF.sub.z where a=1-10, x≥0, y≥1, z≥0, x+y+z=a, 2a or 2a+2, but the iodine-containing additive gas delivered to the reaction chamber is different from the iodine-containing precursor delivered to the reaction chamber. That is, an iodine-containing molecule, having a formula C.sub.aH.sub.xI.sub.yF.sub.z where a=1-10, x≥0, y≥1, z≥0, x+y+z=a, 2a or 2a+2, will not be used simultaneously as a precursor and an additive gas. The iodine-containing additive gas may be CH.sub.3I, C.sub.2H.sub.5I, CF.sub.3I, C.sub.2F.sub.5I, C.sub.2H.sub.2F.sub.3I, saturated or unsaturated linear, branched, cyclic such as C.sub.6H.sub.5I, C.sub.6H.sub.4I.sub.2, C.sub.3F.sub.5I, C.sub.2F.sub.3I etc. or combination thereof, When CH.sub.3I is used as the iodine-containing precursor, the iodine-containing additive gas will not be CH.sub.3I. Similarly, when C.sub.2H.sub.2F.sub.3I is used as the iodine-containing precursor, the iodine-containing additive gas will not be C.sub.2H.sub.2F.sub.3I. That is, the iodine-containing precursor and the iodine-containing additive gas are not the same molecules when they used in a deposition process.
[0223] The co-reactant may be the oxygen-containing molecules stated above.
[0224] The disclosed Iodine-containing film forming composition and the co-reactant may be introduced into the reactor either simultaneously (CVD), sequentially (ALD) or different combinations thereof. The reactor may be purged with an inert gas (e.g., Ar, He, Kr, Xe, Ne) between the introduction of the film forming composition and the introduction of the co-reactant. Alternatively, the co-reactant and the film forming composition may be mixed together to form a co-reactant/compound mixture, and then introduced to the reactor in a mixture form. Another example is to introduce the co-reactant continuously and to introduce the disclosed film forming composition by pulse (pulsed CVD). Another example is to introduce the co-reactant continuously and to introduce the film forming composition by pulse, while activating the co-reactant sequentially with a plasma, provided that the film forming composition and the non-activated co-reactant do not substantially react at the chamber temperature and pressure conditions (CW PEALD).
[0225] An inert gas is also introduced into the reaction chamber as a co-reactant in order to sustain the plasma. The inert gas may be He, Ar, Xe, Kr, Ne, or combinations thereof. The film forming composition and the inert gas may be mixed prior to introduction to the chamber, with the inert gas comprising between approximately 0.01% v/v and approximately 99.9% v/v of the resulting mixture. Alternatively, the inert gas may be introduced to the chamber continuously while the film forming composition is introduced to the chamber in pulses.
[0226] The disclosed film forming composition and co-reactant may be delivered into the reaction chamber in pulse. Each pulse of the disclosed film forming composition, if applied, may last for a time period ranging from about 0.001 seconds to about 30 minutes, alternatively from about 1 seconds to about 120 seconds, alternatively from about 5 seconds to about 60 seconds. The co-reactant may also be pulsed into the reactor, In such embodiments, the pulse of each may last for a time period ranging from about 0.01 seconds to about 30 minutes, alternatively from about 1 seconds to about 120 seconds, alternatively from about 2 seconds to about 60 seconds. In another alternative, the vaporized film forming compositions and co-reactants may be simultaneously sprayed from different sectors of a shower head (without mixing of the composition and the reactant) under which a susceptor holding several wafers is spun (spatial ALD).
[0227] The disclosed iodine-containing film forming composition and co-reactants may be mixed with other gases either prior to introduction into the reaction chamber or inside the reaction chamber. Preferably, the gases may be mixed prior to introduction to the chamber in order to provide a uniform concentration of the entering gas.
[0228] In another alternative, the vapor of the disclosed Iodine-containing film forming composition and co-reactants may be introduced into the chamber independently of the other gases, such as when two or more of the gases react or are easier to deliver independently.
[0229] In another alternative, the vapor of the disclosed Iodine-containing film forming composition and co-reactants are the only gases that are used during the deposition process.
[0230] In another alternative, the disclosed Iodine-containing film forming composition and the nitrogen-containing molecule are the only two gases that are used during the deposition process.
[0231] In another alternative, the disclosed Iodine-containing film forming composition, the nitrogen-containing molecule and the inert gas are the only three gases that are used during the deposition process.
[0232] In another alternative, the disclosed Iodine-containing film forming composition, the nitrogen-containing molecule and the oxidizer are the only three gases that are used during the deposition process.
[0233] In another alternative, the disclosed Iodine-containing film forming composition, the nitrogen-containing molecule, the additive gas and the oxidizer are the only gases that are used during the deposition process.
[0234] In another alternative, the disclosed Iodine-containing film forming composition, the nitrogen-containing molecule, the additive gas and the inert gas are the only gases that are used during the deposition process.
[0235] The vapor of the disclosed film forming composition is activated by plasma to produce an activated film forming composition. The plasma decomposes the film forming composition into radical form (i.e., the activated film forming composition). The same plasma treating process may be applied to the co-reactant including the inert gas, the nitrogen-containing molecule, the oxidizer and the additive gas. The plasma may be generated by applying RF or DC power. The plasma may be generated with a RF power ranging from about 25 W to about 100000 W, preferably, from about 100 W to about 25,000 W. The plasma may be generated remotely or within the reactor itself. The plasma may be generated in dual CCP or ICP mode with RF applied at both electrodes. RF frequency of plasma may range from 100 KHz to 1 GHz. Different RF sources at different frequency may be coupled and applied at same electrode. Plasma RF pulsing may be further used to control molecule fragmentation and reaction at substrate. One of skill in the art will recognize methods and apparatus suitable for such plasma treatment.
[0236] A quadrupole mass spectrometer (QMS), optical emission spectrometer (OES), FTIR, XPS, or other radical/ion measurement tools may measure the activated film forming composition from the chamber exhaust to determine the types and numbers of species produced. If necessary, the flow rate of the film forming composition and/or the inert gas may be adjusted to increase or decrease the number of radical species produced.
[0237] Upon obtaining a desired film thickness, the film may be subject to further processing, such as thermal annealing, furnace-annealing, rapid thermal annealing, photonic curing, UV curing, UV e-beam curing, laser curing, microwave curing, capping layers and/or plasma gas exposure.
[0238] After annealing, the films deposited by any of the disclosed processes may have a bulk resistivity at room temperature of approximately 1 μohn.Math.cm to approximately 1 Mohm.Math.cm. Room temperature is approximately 20° C. to approximately 25° C. depending on the season. Bulk resistivity is also known as volume resistivity. One of ordinary skill in the art will recognize that the bulk resistivity is measured at room temperature on the films that are typically approximately 50 nm thick. The bulk resistivity typically increases for thinner films due to changes in the electron transport mechanism. The bulk resistivity also increases at higher temperatures.
EXAMPLES
[0239] 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.
[0240] Experiments were carried out with commercial LAM tool 4520XLe 200 mm plasma etch tool (CCP dual frequency plasma with 10 gas lines).
[0241] Planar wafers tested are: [0242] 350 nm PE-CVD amorphous carbon (a-C) on Si substrate (purchased from Advantive Tech). [0243] 300 nm spin-on carbon (SOC) on Si substrate (purchased from SKW).
[0244] For planar test, the atomic polymer composition was evaluated through Kratos Axis Supra X-ray photoelectron spectroscopy (XPS) at different conditions tuning through LAM tool such as partial pressure of testing molecules, chuck/bottom temperature, 27 MHz source power and 2 MHz bias power. Two gases used during process are testing molecule and Ar.
[0245] In order to calculate the atomic concentration of elements inside the film, the following XPS method is employed: Monochromatic Al Kα (1486.6 eV), 10 mA of emission current, band pass every of 160, step size of 0.5 eV. In addition, XPS high resolution spectra was also used to determine the presence of different bonding, such spectra was collected via following method: Monochromatic Al Kα (1486.6 eV), 10 mA of emission current, band pass every of 20, step size of 0.1 eV.
[0246] Two commercially available molecules, CH.sub.3I and C.sub.2H.sub.2F.sub.3I were tested using the Lam 200 mm etch chamber under a variety of plasma process conditions by varying plasma power, temperature, flow rates, and pressure. In addition, we tested 2-C.sub.3F.sub.7I (CAS#677-69-0) as baseline process.
[0247] Baseline reference data: 2-C.sub.3F.sub.7I was evaluated as baseline etch compound to quantify the iodine concentration into the a-C layer. In order to simulate the polymer layer formation occurring on the top surface and on the sidewall during plasma processing etch of patterns the process condition were tuned: a-C layer coupons were etched at 30 mTorr for 60 sec, source power 750 W (27 MHz), and bias power 0 W (2 MHz) at the substrate. The process feed the mixture contains 250 sccm of Ar, 15 sccm of 2-C.sub.3F.sub.7I and no O.sub.2. The neutrals and the active species reaching the surface stick to the surface, based on their sticking coefficient, and deposit a thin polymer layer. Table 3 is XPS results show Iodine, carbon, fluorine and oxygen atomic concentration on amorphous carbon surface. Atomic concentration of iodine is 1.8%.
[0248] The atomic concentration of the elements detected with XPS at the surface of a-C. The XPS data is collected via Monochromatic Al Kα (1486.6 eV), 10 mA of emission current, band pass every of 160, step size of 0.5 eV. This XPS method is employed to collect atomic concentration results for subsequent data.
TABLE-US-00003 TABLE 3 I3d C1s F1s O1s Atomic concentration (%) 1.8 69.0 20.2 9.0
Example 1
PECVD Using CH.SUB.3.I
[0249] During plasma process, iodine-containing gas may be generated into the following forms: 1) iodine ion (I.sup.+, I.sup.−); 2) iodine radical (I.Math.); 3) iodine-containing polymeric ion (.sup.+C.sub.xH.sub.yI.sub.zF.sub.d, .sup.−C.sub.xH.sub.yI.sub.zF.sub.d, and 4) iodine-containing polymeric radicals (.Math.C.sub.xH.sub.yI.sub.zF.sub.d). The first form of iodine may be deposited to carbon surface through control of bias power. In addition, the later form will deposit as polymer layer. In this exemplary experiment, iodine-containing gas CH.sub.3I used as a film forming precursor to deposit an iodine-containing polymer layer on a planar wafer (350 nm PE-CVD a-C on Si substrate (purchased from Advantive Tech), or 300 nm spin-on carbon (SOC) on Si substrate (purchased from SKW)). Table 4 shows the process conditions of varying bottom electrode powers of LAM tool for deposition of CH.sub.3I through PE-CVD.
TABLE-US-00004 TABLE 4 Source power Varied Bias power Varied Source temperature 30° C. Bias/chuck electrode temperature 20° C. Gap 1.35 cm Pressure 200 mTorr Ar/CH.sub.3l flow rates 150/30 sccm O.sub.2 0 sccm Reaction time 15 s
[0250]
[0251] Substrate temperature may be controlled through chuck/bottom temperature. Such process conditions shown in Table 5, process conditions of varying bottom electrode temperature, may adjust the iodine concentration on the surface of carbon-containing material due to volatility of iodine and iodine-containing species as shown in
TABLE-US-00005 TABLE 5 Source power 500 W Bias power Varied Source temperature 30° C. Bias/chuck electrode temperature Varied Gap 1.35 cm Pressure 200 mTorr Ar/CH.sub.3l flow rates 150/70 sccm Reaction time 15
[0252] Process pressure and flow ratio of CH.sub.3I and Ar may be tuned to improve iodine concentration. Such process conditions, that is, process pressure tuning, are shown in Table 6, and flow ratio tuning shown in Table 7 may adjust the iodine concentration on the surface of carbon-containing material.
TABLE-US-00006 TABLE 6 Source power 500 W Bias power 500 W Source temperature 30° C. Bias/chuck electrode temperature 20° C. Gap 1.35 cm Pressure Varied Ar/CH.sub.3l flow rates 150/70 sccm Reaction time 15 s
TABLE-US-00007 TABLE 7 Source power 500 W Bias power 500 W Source temperature 30° C. Bias/chuck electrode temperature 20° C. Gap 1.35 cm Pressure 200 mTorr Ar/CH.sub.3l flow rates Varied Reaction time 15 s
Example 2
Stability Test of Deposited Iodine-Containing Carbon Film Using CH.SUB.3.I
[0253] It is known that iodine-containing molecules are unstable under light, and moisture. Hence, it is critical to test the formed films under these conditions. The tested iodine-containing carbon film was prepared under following condition: source power 500 W/bias power 500 W, source temperature 30° C., bias/chuck electrode temperature 20° C., gap 1.35 cm, pressure varied, Ar/CH.sub.3I, 150/70 sccm, reaction time 15 s. These synthesized film was carried out two stability test: 1) Moisture test (samples were sitting in ambient condition [room-air], at room temperature, in a dark box, in 1 week exposure), and light test (samples were sitting in N.sub.2 condition, at room temperature, in 1 week exposure to room light). The results of iodine concentration stability may be found in
[0254] XPS Data analysis: the deposited iodine-containing carbon film is further analyzed by XPS (Monochromatic Al Kα (1486.6 eV), 10 mA of emission current, band pass every of 20, step size of 0.1 eV). The analyzed iodine-containing carbon film was prepared under following condition; source power 500 W/bias power 500 W, source temperature 30° C., bias/chuck electrode temperature 20° C., gap 1.35 cm, pressure Varied, Ar/CH.sub.3I, 150/70 sccm, reaction time 15 s. As shown in
Example 3
Plasma Deposition Using C.SUB.2.H.SUB.2.F.SUB.3.I via Lam Tool Etcher
[0255] C.sub.2H.sub.2F.sub.3I was used as a film-forming precursor to deposit an iodine-containing polymer film on a-C layer. As discuss in the previous examples, iodine ions, iodine radicals and iodine-containing species may be controlled through source power and bias power. This process control (shown in Table 8) results in optimal condition for iodine concentration on carbon-containing material as shown in
TABLE-US-00008 TABLE 8 Source power Varied Bias power Varied Source temperature 30° C. Bias/chuck electrode temperature 20° C. Gap 1.35 cm Pressure 200 mTorr Ar/C.sub.2H.sub.2F.sub.3l flow rates 150/30 sccm Reaction time 15 s
Example 4
Plasma Deposition Using CH.SUB.3.I and C.SUB.3.HF.SUB.4.N via LAM Tool Etcher
[0256] CH.sub.3I and C.sub.3HF.sub.4N were used as a film-forming precursor and an N-containing co-reactant to deposit an iodine-containing polymer film on a-C layer. For comparison, CH.sub.3I and N.sub.2 were used as a film-forming precursor and an N-containing co-reactant to deposit an iodine-containing polymer film on a-C layer. As discuss in the previous examples, during plasma process, iodine-containing gas may be generated into three forms: 1) iodine ion (I.sup.+, I.sup.−); 2) iodine radical (I.Math.); 3) iodine containing polymeric ion (.sup.+C.sub.xH.sub.yI.sub.zF.sub.d, .sup.−C.sub.xH.sub.yI.sub.zFd, and 4) iodine containing polymeric radicals (.Math.C.sub.xH.sub.yI.sub.zF.sub.d). The first and third form of iodine may be deposited to carbon surface through control of the bias power. In addition, these chemical forms will deposit as a polymer layer that could enhance EUV absorption of layer during patterning process. These iodine forms may be further captured by nitrogen species from C.sub.3HF.sub.4N at the gas phase as well as the surface of deposited polymer forming a deposited iodine and nitrogen containing carbon film. Such process condition of LAM tool etcher is shown in Table 9.
TABLE-US-00009 TABLE 9 Source power 500 W Bias power 500 W Source temperature 30° C. Bias/chuck electrode temperature 20° C. Gap 1.35 cm Pressure 200 mTorr Ar/CH.sub.3l flow rates 150/70 sccm C.sub.3HF.sub.4N or N.sub.2 flow rates 15 sccm Reaction time 16
[0257] The deposited iodine and nitrogen containing carbon film is further analyzed by Kratos Axis Supra X-ray photoelectron spectroscopy (XPS).
[0258] The analyzed iodine containing carbon film was prepared under following condition: source power 500 W/bias power 500 W, source temperature 30° C., bias/chuck electrode temperature 20° C., gap 1.35 cm, pressure 200 mTorr, Ar/CH.sub.3I/C.sub.3HF.sub.4N, 150/70/15 sccm, or reaction time 15 s. As shown in
[0259] In summary, the disclosed methods are providing not only a new/novel chemistry to deposit an iodine film on carbon surface, but also a method to enhance iodine concentration doped in the carbon surface. Such iodine-modified layer may be utilized in various applications in semiconductor fabricating device.
[0260] Although the subject matter described herein may be described in the context of illustrative implementations to process one or more computing application features/operations for a computing application having user-interactive components the subject matter is not limited to these particular embodiments. Rather, the techniques described herein can be applied to any suitable type of user-interactive component execution management methods, systems, platforms, and/or apparatus.
[0261] 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.
[0262] 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.