High Oxide VS Nitride Selectivity, Low And Uniform Oxide Trench Dishing In Shallow Trench Isolation(STI) Chemical Mechanical Planarization Polishing(CMP)
20200095502 ยท 2020-03-26
Assignee
Inventors
- Xiaobo Shi (Chandler, AZ, US)
- Joseph D. Rose (Gilbert, AZ, US)
- Krishna P. Murella (Phoenix, AZ, US)
- Hongjun Zhou (Chandler, AZ, US)
- Mark Leonard O'Neill (Queen Creek, AZ, US)
Cpc classification
C09K13/00
CHEMISTRY; METALLURGY
International classification
Abstract
Present invention provides Chemical Mechanical Planarization Polishing (CMP) compositions for Shallow Trench Isolation (STI) applications. The CMP compositions contain ceria coated inorganic oxide particles as abrasives, such as ceria-coated silica particles or any other ceria-coated inorganic oxide particles as core particles; suitable chemical additives comprising at least one organic carboxylic acid group, at least one carboxylate salt group or at least one carboxylic ester group and two or more hydroxyl functional groups in the same molecule; and a water soluble solvent; and optionally biocide and pH adjuster; wherein the composition has a pH of 2 to 12, preferably 3 to 10, and more preferably 4 to 9.
Claims
1. A chemical mechanical polishing composition comprising: ceria-coated inorganic oxide particles; 0.0006 wt. % to 0.25 wt. % of a chemical additive comprising at least one organic carboxylic acid group(s), at least one carboxylate salt group, or at least one carboxylic ester group; and at least two hydroxyl functional groups in the same molecule; water soluble solvent; and optionally biocide; pH adjuster; wherein the composition has a pH of 4 to 9; and the chemical additive has a general molecular structure of: ##STR00017## (a) or ##STR00018## wherein n and m are independently selected from 2 to 12; R1, R2, and R3 can be the same or different atoms or functional groups and are independently selected from the group consisting of hydrogen; alkyl; alkoxy; organic group with at least one hydroxyl groups; substituted organic sulfonic acid; substituted organic sulfonic acid salt; substituted organic carboxylic acid; substituted organic carboxylic acid salt; organic carboxylic ester; organic amine group; metal ion selected from the group comprising sodium ion, potassium ion, and ammonium ion; and combinations thereof; wherein at least two of R1, R2, and R3 are hydrogen atoms.
2. The chemical mechanical polishing composition of claim 1, wherein the ceria-coated inorganic oxide particles range from 0.1 wt. % to 5 wt. % and are selected from the group consisting of ceria-coated colloidal silica, ceria-coated high purity colloidal silica, ceria-coated alumina, ceria-coated titania, ceria-coated zirconia particles and combinations thereof.
3. The chemical mechanical polishing composition of claim 1, wherein the water-soluble solvent is selected from the group consisting of deionized (DI) water, distilled water, and alcoholic organic solvents.
4. The chemical mechanical polishing composition of claim 1, wherein the chemical additive ranges from 0.0007 wt. % to 0.1 wt. %; and the composition has a pH of 4.5 to 7.5
5. The chemical mechanical polishing composition of claim 1, wherein the chemical additive is selected from the group consisting of tartaric acid, cholic acid, shikimic acid, mucic acid with two acid groups, asiatic acid, 2,2-Bis(hydroxymethyl)propionic acid, gluconic acid, sodium gluconate salt, potassium gluconate salt, gluconate ammonium salt, gluconic acid, methyl ester, and combinations thereof.
6. The chemical mechanical polishing composition of claim 1, wherein the chemical additive is selected from the group consisting of gluconic acid, gluconic acid methyl ester, gluconic acid, ethyl ester, and combinations thereof.
7. The chemical mechanical polishing composition of claim 1, wherein the composition comprises ceria-coated colloidal silica particles; the chemical additive selected from the group consisting of gluconic acid, gluconate salts, gluconic acid alkyl esters and combinations thereof; and water.
8. The chemical mechanical polishing composition of claim 1, wherein the composition further comprises at least one of from 0.0005 wt. % to 0.025 wt. % of the biocide having active ingredients of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-1-isothiazolin-3-one; from 0.01 wt. % to 0.5 wt. % of the pH adjusting agent selected from the group consisting of nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid, other inorganic or organic acids, and mixtures thereof for acidic pH conditions; or selected from the group consisting of sodium hydride, potassium hydroxide, ammonium hydroxide, tetraalkyl ammonium hydroxide, organic quaternary ammonium hydroxide compounds, organic amines, and combinations thereof for alkaline pH conditions.
9. A method of chemical mechanical polishing (CMP) a semiconductor substrate having at least one surface comprising silicon oxide film, comprising providing the semiconductor substrate; providing a polishing pad; providing chemical mechanical polishing (CMP) composition comprising ceria-coated inorganic oxide particles; 0.0006 wt. % to 0.25 wt. % of a chemical additive comprising at least one organic carboxylic acid group(s), at least one carboxylate salt group, or at least one carboxylic ester group; and at least two hydroxyl functional groups in the same molecule; water soluble solvent; and optionally biocide; pH adjuster; wherein the composition has a pH of 4 to 9; and the chemical additive has a general molecular structure of: ##STR00019## (a) or ##STR00020## wherein n and m are independently selected from 2 to 12; R1, R2, and R3 can be the same or different atoms or functional groups and are independently selected from the group consisting of hydrogen; alkyl; alkoxy; organic group with at least one hydroxyl groups; substituted organic sulfonic acid; substituted organic sulfonic acid salt; substituted organic carboxylic acid; substituted organic carboxylic acid salt; organic carboxylic ester; organic amine group; metal ion selected from the group comprising sodium ion, potassium ion, and ammonium ion; and combinations thereof; wherein at least two of R1, R2, and R3 are hydrogen atoms; contacting the surface of the semiconductor substrate with the polishing pad and the chemical mechanical polishing composition; and polishing the least one surface comprising silicon dioxide.
10. The method of claim 9; wherein the ceria-coated inorganic oxide particles range from 0.1 wt. % to 5 wt. % and are selected from the group consisting of ceria-coated colloidal silica, ceria-coated high purity colloidal silica, ceria-coated alumina, ceria-coated titania, ceria-coated zirconia particles and combinations thereof; the water-soluble solvent is selected from the group consisting of deionized (DI) water, distilled water, and alcoholic organic solvents, and the silicon oxide film is selected from the group consisting of Chemical vapor deposition (CVD), Plasma Enhance CVD (PECVD), High Density Deposition CVD (HDP), or spin on silicon oxide film.
11. The method of claim 9, wherein the chemical additive ranges from 0.0007 wt. % to 0.1 wt. %; and the composition has a pH of 4.5 to 7.5
12. The method of claim 9, wherein the chemical additive is selected from the group consisting of tartaric acid, cholic acid, shikimic acid, mucic acid with two acid groups, asiatic acid, 2,2-Bis(hydroxymethyl)propionic acid, gluconic acid, sodium gluconate salt, potassium gluconate salt, gluconate ammonium salt, gluconic acid, methyl ester, and combinations thereof.
13. The method of claim 9, wherein the composition comprises ceria-coated colloidal silica particles; the chemical additive ranges from 0.0007 wt. % to 0.1 wt. % and is selected from the group consisting of gluconic acid, gluconate salts, gluconic acid alkyl esters and combinations thereof; and water.
14. The method of claim 9; wherein the semiconductor substrate further comprises a silicon nitride surface; and removal selectivity of silicon oxide: silicon nitride is greater than 25.
15. A system of chemical mechanical polishing (CMP) a semiconductor substrate having at least one surface comprising silicon oxide film, comprising a. the semiconductor substrate; b. chemical mechanical polishing (CMP) composition comprising 1) ceria-coated inorganic oxide particles; 2) 0.0006 wt. % to 0.25 wt. % of a chemical additive comprising at least one organic carboxylic acid group(s), at least one carboxylate salt group, or at least one carboxylic ester group; and at least two hydroxyl functional groups in the same molecule; 3) water soluble solvent; and 4) optionally 5) biocide; 6) pH adjuster; wherein the composition has a pH of 4 to 9; and the chemical additive has a general molecular structure of: ##STR00021## (a) or ##STR00022## wherein n and m are independently selected from 2 to 12; R1, R2, and R3 and can be the same or different atoms or functional groups and are independently selected from the group consisting of hydrogen; alkyl; alkoxy; organic group with at least one hydroxyl groups; substituted organic sulfonic acid; substituted organic sulfonic acid salt; substituted organic carboxylic acid; substituted organic carboxylic acid salt; organic carboxylic ester; organic amine group; metal ion selected from the group comprising sodium ion, potassium ion, and ammonium ion; and combinations thereof; wherein at least two of R1, R2, and R3 are hydrogen atoms; c. a polishing pad; wherein the at least one surface comprising silicon oxide film is in contact with the polishing pad and the chemical mechanical polishing composition.
16. The system of claim 15; wherein the ceria-coated inorganic oxide particles range from 0.1 wt. % to 5 wt. % and are selected from the group consisting of ceria-coated colloidal silica, ceria-coated high purity colloidal silica, ceria-coated alumina, ceria-coated titania, ceria-coated zirconia particles and combinations thereof; the water-soluble solvent is selected from the group consisting of deionized (DI) water, distilled water, and alcoholic organic solvents, and the silicon oxide film is selected from the group consisting of Chemical vapor deposition (CVD), Plasma Enhance CVD (PECVD), High Density Deposition CVD (HDP), or spin on silicon oxide film.
17. The system of claim 15; wherein the chemical additive ranges from 0.0007 wt. % to 0.1 wt. %; and the composition has a pH of 4.5 to 7.5
18. The system of claim 15; wherein the chemical additive is selected from the group consisting of tartaric acid, cholic acid, shikimic acid, mucic acid with two acid groups, asiatic acid, 2,2-Bis(hydroxymethyl)propionic acid, gluconic acid, sodium gluconate salt, potassium gluconate salt, gluconate ammonium salt, gluconic acid, methyl ester, and combinations thereof.
19. The system of claim 15; wherein the composition comprises ceria-coated colloidal silica particles; the chemical additive ranges from 0.0007 wt. % to 0.1 wt. % and is selected from the group consisting of gluconic acid, gluconate salts, gluconic acid alkyl esters and combinations thereof; and water.
20. The system of claim 15; wherein the semiconductor substrate further comprises a silicon nitride surface; and removal selectivity of silicon oxide: silicon nitride is greater than 25.
Description
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
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DETAILED DESCRIPTION OF THE INVENTION
[0052] In the global planarization of patterned STI structures, suppressing SiN removal rates and reducing oxide trench dishing and providing more uniform oxide trench dishing across various sized oxide trench features are key factors to be considered. The lower trench oxide loss will prevent electrical current leaking between adjacent transistors. Non-uniform trench oxide loss across die (within Die) will affect transistor performance and device fabrication yields. Severe trench oxide loss (high oxide trench dishing) will cause poor isolation of transistor resulting in device failure. Therefore, it is important to reduce trench oxide loss by reducing oxide trench dishing in STI CMP polishing compositions.
[0053] This invention relates to the Chemical mechanical polishing (CMP) compositions for Shallow Trench Isolation (STI) CMP applications.
[0054] More specifically, the disclosed chemical mechanical polishing (CMP) composition for Shallow Trench Isolation (STI) CMP applications have a unique combination of using ceria-coated inorganic metal oxide inorganic metal oxide abrasive particles and the suitable chemical additives as oxide trench dishing reducing agents and nitride suppressing agents.
[0055] The suitable chemical additives include, but are not limited to organic carboxylic acid molecules, organic carboxylate salts or organic carboxylic ester molecules bearing multi hydroxyl functional groups in the same molecules.
[0056] The chemical additives contain at least one organic carboxylic acid group, one carboxylate salt group or one carboxylic ester group and two or more hydroxyl functional groups in the same molecules.
[0057] The chemical additives provide the benefits of achieving high oxide film removal rates, low SiN film removal rates, high and tunable Oxide: SiN selectivity, and more importantly, significantly reducing oxide trench dishing and improving over polishing window stability on polishing patterned wafers.
[0058] In one aspect, there is provided a STI CMP polishing composition comprises:
ceria-coated inorganic metal oxide particles;
chemical additives as SiN film removal rate suppressing agents and oxide trenching dishing reducers on polishing patterned wafers;
a water-soluble solvent; and
optionally
biocide; and
pH adjuster;
wherein the composition has a pH of 2 to 12, preferably 3 to 10, more preferably 4 to 9, and most preferably 4.5 to 7.5.
[0059] The ceria-coated inorganic metal oxide particles include, but are not limited to, ceria-coated colloidal silica, ceria-coated high purity colloidal silica, ceria-coated alumina, ceria-coated titania, ceria-coated zirconia, or any other ceria-coated inorganic metal oxide particles.
[0060] The particle sizes (measured by Dynamic Light Scattering DLS technology) of these ceria-coated inorganic metal oxide particles in the disclosed invention herein are ranged from 10 nm to 1,000 nm, the preferred mean particle sized are ranged from 20 nm to 500 nm, the more preferred mean particle sizes are ranged from 50 nm to 250 nm.
[0061] The concentrations of these ceria-coated inorganic metal oxide particles range from 0.01 wt. % to 20 wt. %, the preferred concentrations range from 0.05 wt. % to 10 wt. %, the more preferred concentrations range from 0.1 wt. % to 5 wt. %.
[0062] The preferred ceria-coated inorganic metal oxide particles are ceria-coated colloidal silica particles.
[0063] The preferred chemical additive as SiN film removal rate suppressing agents and oxide trenching dishing reducers comprise at least one carboxylic acid group (RCOOH), at least one carboxylate salt group(s) or at least one carboxylic ester group; and at least two hydroxyl functional groups (OH) in the same molecule;
[0064] Some of these chemical additives have a general molecular structure as shown below:
##STR00009##
[0065] In the general molecular structure (a) or (b), n is selected from 1 to 5,000, the preferred n is from 2 to 12, the more preferred n is from 3 to 6.
[0066] R1, R2, R3, and R4 can be the same or different atoms or functional groups. They can be independently selected from the group consisting of hydrogen, alkyl, alkoxy, organic group with one or more hydroxyl groups, substituted organic sulfonic acid, substituted organic sulfonic acid salt, substituted organic carboxylic acid, substituted organic carboxylic acid salt, organic carboxylic ester, organic amine groups, and combinations thereof; wherein, at least two or more, preferably three or more are hydrogen atoms.
[0067] In addition, R1, R4, or both R1 and R4 can also be a metal ion or ammonium ion. The metal ion includes but is not limited to sodium ion, potassium ion.
[0068] When R1, R2, R3 and R4 are all hydrogen atoms, the chemical additive bears one (structure (a)) or two (structure (b)) organic carboxylic acid groups and two (structure (b)) or more (structure (a)) hydroxyl functional groups.
[0069] The molecular structures of some examples of such chemical additives are listed below:
##STR00010## ##STR00011##
[0070] When R1 is a metal ion or ammonium ion in structure (a), the chemical additives have general molecular structures as listed below:
##STR00012##
[0071] When R1 and R4 are both metal ions, or ammonium ions in structure (b), the chemical additives have general molecular structures as listed below:
##STR00013##
[0072] When R 1 is a metal ion and R2, R3, and R4 are all hydrogen atoms in structure (i), the molecular structures of some examples of such chemical additives are listed below:
##STR00014##
[0073] When R1 is an organic alkyl group in structure (a), the chemical additive has the organic acid ester functional group and bearing multi hydroxyl functional groups in the same molecule. The general molecular structure is shown below.
##STR00015##
[0074] When R2, R3, and R4 are hydrogen atoms in structure (v), the molecular structures of an examples of such chemical additive is shown below:
##STR00016##
[0075] The STI CMP composition contains 0.0001 wt. % to 2.0% wt. %, 0.0002 wt. % to 1.0 wt. %, 0.0003 wt. % to 0.75 wt. %, 0.0004 wt. % to 0.5 wt. %, 0.0005 wt. % to 0.5 wt. %, 0.0006 wt. % to 0.25 wt. %, or 0.0007 wt. % to 0.1 wt. % chemical additives as SiN film removal rate suppressing agents and oxide trenching dishing reducers.
[0076] The water-soluble solvent includes but is not limited to deionized (DI) water, distilled water, and alcoholic organic solvents.
[0077] The preferred water-soluble solvent is DI water.
[0078] The STI CMP composition may contain biocide from 0.0001 wt. % to 0.05 wt. %; preferably from 0.0005 wt. % to 0.025 wt. %, and more preferably from 0.001 wt. % to 0.01 wt. %.
[0079] The biocide includes, but is not limited to, Kathon, Kathon CG/ICP II, from Dupont/Dow Chemical Co. Bioban from Dupont/Dow Chemical Co. They have active ingredients of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one.
[0080] The STI CMP composition may contain a pH adjusting agent.
[0081] An acidic or basic pH adjusting agent can be used to adjust the STI polishing compositions to the optimized pH value.
[0082] The pH adjusting agents include, but are not limited to nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid, other inorganic or organic acids, and mixtures thereof.
[0083] pH adjusting agents also include the basic pH adjusting agents, such as sodium hydride, potassium hydroxide, ammonium hydroxide, tetraalkyl ammonium hydroxide, organic quaternary ammonium hydroxide compounds, organic amines, and other chemical reagents that can be used to adjust pH towards the more alkaline direction.
[0084] The STI CMP composition contains 0 wt. % to 1 wt. %; preferably 0.01 wt. % to 0.5 wt. %; more preferably 0.1 wt. % to 0.25 wt. % pH adjusting agent.
[0085] The chemical additives used as SiN film removal rate suppressing agents and oxide trenching dishing reducers are organic carboxylic acid molecules, organic carboxylate salts or organic carboxylic ester molecules bearing multi hydroxyl functional groups in the same molecules.
[0086] In another aspect, there is provided a method of chemical mechanical polishing (CMP) a substrate having at least one surface comprising silicon dioxide using the chemical mechanical polishing (CMP) composition described above in Shallow Trench Isolation (STI) process.
[0087] In another aspect, there is provided a system of chemical mechanical polishing (CMP) a substrate having at least one surface comprising silicon dioxide using the chemical mechanical polishing (CMP) composition described above in Shallow Trench Isolation (STI) process.
[0088] The polished oxide films can be Chemical vapor deposition (CVD), Plasma Enhance CVD (PECVD), High Density Deposition CVD (HDP), or spin on oxide films.
[0089] The substrate disclosed above can further comprises a silicon nitride surface. The removal selectivity of SiO.sub.2:SiN is greater than 25, preferably greater than 30, and more preferably greater than 35.
[0090] In another aspect, there is provided a method of chemical mechanical polishing (CMP) a substrate having at least one surface comprising silicon dioxide using the chemical mechanical polishing (CMP) composition described above in Shallow Trench Isolation (STI) process. The polished oxide films can be CVD oxide, PECVD oxide, High density oxide, or Spin on oxide films.
[0091] The following non-limiting examples are presented to further illustrate the present invention.
CMP Methodology
[0092] In the examples presented below, CMP experiments were run using the procedures and experimental conditions given below.
Glossary
Components
[0093] Ceria-coated Silica: used as abrasive having a particle size of approximately 100 nanometers (nm); such ceria-coated silica particles can have a particle size of ranged from approximately 20 nanometers (nm) to 500 nanometers (nm);
[0094] Ceria-coated Silica particles (with varied sizes) were supplied by JGC Inc. in Japan and were made by methods described in patent publications JP2013119131, JP2013133255, and WO 2016/159167; and patent applications JP2015-169967, and JP2015-183942.
[0095] Chemical additives, such as maltitol, D-Fructose, Dulcitol, D-sorbitol, gluconic acid, mucic acid, tartaric acid and other chemical raw materials were supplied by Sigma-Aldrich, St. Louis, Mo.
[0096] TEOS: tetraethyl orthosilicate
[0097] Polishing Pad: Polishing pad, IC1010 and other pads were used during CMP, supplied by DOW, Inc.
Parameters
General
[0098] or A: angstrom(s)a unit of length
[0099] BP: back pressure, in psi units
[0100] CMP: chemical mechanical planarization=chemical mechanical polishing
[0101] CS: carrier speed
[0102] DF: Down force: pressure applied during CMP, units psi
[0103] min: minute(s)
[0104] ml: milliliter(s)
[0105] mV: millivolt(s)
[0106] psi: pounds per square inch
[0107] PS: platen rotational speed of polishing tool, in rpm (revolution(s) per minute)
[0108] SF: composition flow, ml/min
[0109] Wt. %: weight percentage (of a listed component)
[0110] TEOS: SiN Selectivity: (removal rate of TEOS)/(removal rate of SiN)
[0111] HDP: high density plasma deposited TEOS
[0112] TEOS or HDP Removal Rates: Measured TEOS or HDP removal rate at a given down pressure. The down pressure of the CMP tool was 2.0, 3.0 or 4.0 psi in the examples listed above.
[0113] SiN Removal Rates: Measured SiN removal rate at a given down pressure. The down pressure of the CMP tool was 3.0 psi in the examples listed.
Metrology
[0114] Films were measured with a ResMap CDE, model 168, manufactured by Creative Design Engineering, Inc, 20565 Alves Dr., Cupertino, Calif., 95014. The ResMap tool is a four-point probe sheet resistance tool. Forty-nine-point diameter scan at 5 mm edge exclusion for film was taken.
CMP Tool
[0115] The CMP tool that was used is a 200 mm Mirra, or 300 mm Reflexion manufactured by Applied Materials, 3050 Boweres Avenue, Santa Clara, Calif., 95054. An IC1000 pad supplied by DOW, Inc, 451 Bellevue Rd., Newark, Del. 19713 was used on platen 1 for blanket and pattern wafer studies.
[0116] The IC1010 pad or other pad was broken in by conditioning the pad for 18 mins. At 7 lbs. down force on the conditioner. To qualify the tool settings and the pad break-in two tungsten monitors and two TEOS monitors were polished with Versum ST12305 composition, supplied by Versum Materials Inc. at baseline conditions.
Wafers
[0117] Polishing experiments were conducted using PECVD or LECVD or HD TEOS wafers. These blanket wafers were purchased from Silicon Valley Microelectronics, 2985 Kifer Rd., Santa Clara, Calif. 95051.
Polishing Experiments
[0118] In blanket wafer studies, oxide blanket wafers, and SiN blanket wafers were polished at baseline conditions. The tool baseline conditions were: table speed; 87 rpm, head speed: 93 rpm, membrane pressure; 2.0 psi, inter-tube pressure; 2.0 psi, retaining ring pressure; 2.9 psi, composition flow; 200 ml/min.
[0119] The composition was used in polishing experiments on patterned wafers (MIT860), supplied by SWK Associates, Inc. 2920 Scott Blvd. Santa Clara, Calif. 95054). These wafers were measured on the Veeco VX300 profiler/AFM instrument. The 3 different sized pitch structures were used for oxide dishing measurement. The wafer was measured at center, middle, and edge die positions.
[0120] TEOS: SiN Selectivity: (removal rate of TEOS)/(removal rate of SiN) obtained from the STI CMP polishing compositions were tunable.
WORKING EXAMPLES
[0121] In the following working examples, a STI polishing composition comprising 0.2 wt. % cerium-coated silica, a biocide ranging from 0.0001 wt. % to 0.05 wt. %, and deionized water was prepared as reference (ref.).
[0122] The working polishing compositions were prepared with the reference (0.2 wt. % cerium-coated silica, a biocide ranging from 0.0001 wt. % to 0.05 wt. %, and deionized water) and a disclosed chemical additive in the range of 0.0025 wt. % to 0.015% wt. %.
Example 1
[0123] In Example 1, the polishing compositions used were shown in Table 1. The reference sample was made using 0.2 wt. % ceria-coated silica plus very low concentration of biocide. The chemical additive, gluconic acid was used at 0.01 wt. %. Both samples have same pH values at around 5.35.
[0124] The removal rates (RR at A/min) for different films were tested. The effects of chemical additive gluconic acid on the film removal rates and selectivity were observed.
[0125] The test results were listed in Table 1 and shown in
TABLE-US-00001 TABLE 1 Effects of Gluconic Acid on Film RR (/min.) & TEOS:SiN Selectivity TEOS-RR HDP-RR SiN-RR TEOS:SiN Compositions (ang/min) (ang/min) (ang/min) Selectivity 0.2% Ceria-coated Silica 2718 2180 349 8:1 0.2% Ceria-coated 2015 2183 56 36:1 Silica + 0.01% Gluconic acid
[0126] As the results shown in Table 1 and
[0127] Thus, the polishing compositions provided the suppressed SiN film removal rates and high Oxide: SiN selectivity.
[0128] The effects of the chemical additive, gluconic acid, in the polishing composition on oxide trench dishing rates were tested. The results were listed in Table 2 and depicted in
TABLE-US-00002 TABLE 2 Effects of Gluconic Acid on Oxide Trench Dishing Rate P100 m P200 m P1000 m Dishing Rate Dishing Rate Dishing Rate Compositions (A/sec.) (A/sec.) (A/sec.) 0.2% Ceria-coated Silica 8.7 10.3 11.5 0.2% Ceria-coated Silica + 2.4 2.6 2.6 0.01% Gluconic acid
[0129] As the results shown in Table 2 and
[0130] The effects of addition of the chemical additive, gluconic acid, in the polishing compositions were also observed on oxide trench loss rates (A/sec.) while comparing the polishing results from the reference sample without using gluconic acid as additive.
[0131] The test results were listed in Table 3 and depicted in
TABLE-US-00003 TABLE 3 Effects of Gluconic Acid on Oxide Trench Loss Rates (A/Sec.) P100 m P200 m P1000 m Trench Loss Trench Loss Trench Loss Composition Rate (A/sec.) Rate (A/sec.) Rate (A/sec.) 0.2% Ceria-coated Silica 18.8 20.4 20.6 0.2% Ceria-coated Silica + 3.5 3.5 3.7 0.01% Gluconic acid
[0132] As the results shown in Table 3 and
[0133] The effects of addition of the chemical additive, gluconic acid, in the polishing compositions were also observed on oxide trench dishing vs over polishing times while comparing the polishing results from the reference sample without using gluconic acid as additive.
[0134] The test results on the effects of chemical additive gluconic acid in the polishing compositions on oxide trench dishing vs over polishing times were listed in Table 4, and depicted in
TABLE-US-00004 TABLE 4 Effects of Gluconic Acid on Oxide Trench Dishing vs OP Times (Sec.) Polish Time 100 m Pitch 200 m Pitch 1000 m Pitch Compositions (Sec.) Dishing Dishing Dishing 0.2% Ceria-coated Silica 0 165 291 1013 60 857 1096 1821 120 1207 1531 2392 0.2% Ceria-coated Silica + 0.01% 0 52 182 992 Gluconic acid 60 203 355 1158 120 344 494 1301
[0135] As the results shown in Table 4,
[0136] Thus, the CMP composition comprised of the chemical additive suppressed SiN removal rates and increasing TEOS: SiN film selectivity, and very effectively reduced oxide trench dishing and provided improved topography on the polished patterned wafers while still afforded high TEOS and HDP film removal rates while comparing the polishing results from the reference sample without using gluconic acid as chemical additive.
Example 2
[0137] In Example 2, the polishing composition were prepared as shown in Table 5. The chemical additive gluconic acid were used at different wt. %. pH for the compositions was all around 5.35.
[0138] The various film polishing removal rates and TEOS: SiN selectivity results were listed in Table 5 and depicted in
TABLE-US-00005 TABLE 5 Effects of Gluconic Acid (GA) % on Film RR (/min.) & TEOS:SiN Selectivity TEOS-R HDP-R SiN-R TEOS:SiN Compositions (ang/min) (ang/min) (ang/min) Selectivity 0.2% Ceria-coated Silica 2718 2180 349 8:1 0.2% Ceria-coated Silica + 0.0025% GA 3655 3609 93 39:1 0.2% Ceria-coated Silica + 0.005% GA 2875 2932 67 43:1 0.2% Ceria-coated Silica + 0.01% GA 1754 1767 53 33:1 0.2% Ceria-coated Silica + 0.015% GA 1854 1914 57 33:1 0.2% Ceria-coated Silica + 0.1% GA 110 91 49 2:1
[0139] As the results shown in Table 5 and
[0140] The Oxide Trench Dishing Rate using the compositions were also tested. The test results were listed in Table 6 and
TABLE-US-00006 TABLE 6 Effects of Gluconic Acid % on Oxide Trench Dishing Rate P100 m Dishing P200 m Dishing P1000 m Dishing Compositions Rate (A/sec.) Rate (A/sec.) Rate (A/sec.) 0.2% Ceria-coated Silica 8.7 10.3 11.5 0.2% Ceria-coated Silica + 0.0025% GA 8.0 10.0 11.8 0.2% Ceria-coated Silica + 0.005% GA 5.7 7.0 12.7 0.2% Ceria-coated Silica + 0.01% GA 2.4 2.6 2.6 0.2% Ceria-coated Silica + 0.015% GA 2.7 3.0 2.9
[0141] As the results shown in Table 6 and
[0142] The effects of addition of the chemical additive, gluconic acid, used at different concentrations in the polishing compositions were also observed on oxide trench loss rates (A/sec.) while comparing the polishing results from the reference sample without using gluconic acid as additive.
[0143] The test results were listed in Table 7 and shown in
TABLE-US-00007 TABLE 7 Effects of Gluconic Acid % on Oxide Trench Loss Rates (A/Sec.) P100 m Trench P200 m Trench P1000 m Trench Loss Rate Loss Rate Loss Rate Compositions (A/sec.) (A/sec.) (A/sec.) 0.2% Ceria-coated Silica 18.8 20.4 20.6 0.2% Ceria-coated Silica + 0.0025% GA 20.0 21.4 21.3 0.2% Ceria-coated Silica + 0.005% GA 11.6 12.7 17.3 0.2% Ceria-coated Silica + 0.01% GA 3.5 3.5 3.7 0.2% Ceria-coated Silica + 0.015% GA 3.7 4.1 4.1
[0144] As the results shown in Table 7 and
[0145] The effects of addition of the chemical additive, gluconic acid, used at different concentrations in the polishing compositions were also observed on oxide trench dishing vs over polishing times while comparing the polishing results from the reference sample without using gluconic acid as additive.
[0146] The test results were listed in Table 8 and shown in
TABLE-US-00008 TABLE 8 Effects of Gluconic Acid % on Oxide Trench Dishing vs OP Times (Sec.) Over Polish 100 um pitch 200 um pitch 1000 um pitch Compositions Time (Sec.) dishing dishing dishing 0.2% Ceria-coated Silica 0 165 291 1013 60 857 1096 1821 120 1207 1531 2392 0.2% Ceria-coated Silica + 0 51 167 1201 0.0025% Gluconic Acid 60 786 1002 1932 120 1012 1370 2616 0.2% 0.2% Ceria-coated Silica + 0 72 186 1205 0.005% Gluconic Acid 60 641 845 2371 120 757 1026 2732 0.2% Ceria-coated Silica + 0.01% 0 52 182 992 Gluconic Acid 60 203 355 1158 120 344 494 1301 0.2% Ceria-coated Silica + 0 65 200 1251 0.015% Gluconic Acid 60 253 380 1433 120 393 559 1601
[0147] As the results shown in Table 8,
[0148] Again, the CMP composition comprised of the chemical additive having different testing concentrations suppressed SiN removal rates and increasing TEOS: SiN film selectivity, and very effectively reduced oxide trench dishing and provided improved topography on the polished patterned wafers while still afforded high TEOS and HDP film removal rates while comparing the polishing results from the reference sample without using gluconic acid as chemical additive.
Example 3
[0149] In Example 3, different pH conditions were tested with gluconic acid used as chemical additive at 0.01 wt. % concentration. The tested compositions and pH conditions were listed used as in Table 9.
[0150] The film removal rates and TEOS: SiN selectivity were listed in Table 9 and depicted in
TABLE-US-00009 TABLE 9 Effects of pH and 0.01 wt. % Gluconic Acid on Film RR (/min.) & TEOS:SiN Selectivity TEOS-RR HDP-RR SiN-RR TEOS:SiN Compositions (ang/min) (ang/min) (ang/min) Selectivity 0.2% Ceria-coated Silica pH 5.35 2718 2180 349 8:1 0.2% Ceria-coated Silica + 0.01% GA pH 5.35 1754 1787 53 33:1 0.2% Ceria-coated Silica + 0.01% GA pH 6.0 1836 1839 52 35:1 0.2% Ceria-coated Silica + 0.01% GA pH 7.0 1429 1488 52 27:1
[0151] As the results shown in Table 9 and
[0152] The effects of pH conditions on the composition using 0.01 wt. % gluconic acid as chemical additive on the various sized oxide trench feature dishing rates were observed and the results were listed in Table 10 and depicted in
TABLE-US-00010 TABLE 10 Effects of pH with 0.01% Gluconic Acid on Oxide Trench Dishing Rate P100 m Dishing P200 m Dishing P1000 m Compositions Rate (A/sec.) Rate (A/sec.) Dishing Rate (A/sec.) 0.2% Ceria-coated Silica pH 5.35 8.7 10.3 11.5 0.2% Ceria-coated Silica + 0.01% GA pH 5.35 2.4 2.6 2.6 0.2% Ceria-coated Silica + 0.01% GA pH 6.0 3.1 3.4 3.4 0.2% Ceria-coated Silica + 0.01% GA pH 7.0 2.8 3.1 3.1
[0153] As the results shown in Table 10 and
[0154] The invented STI CMP polishing compositions herein can be used at the wide pH range which include acidic, neutral or alkaline.
[0155] The effects of pH conditions on the composition using 0.01 wt. % gluconic acid as chemical additive on the various sized oxide trench loss rates were observed and the results were listed in Table 11 and depicted in
TABLE-US-00011 TABLE 11 Effects of pH with 0.01% Gluconic Acid on Oxide Trench Loss Rate P100 m Trench P200 m Trench P1000 m Trench Loss Rate Loss Rate Loss Rate Compositions (A/sec.) (A/sec.) (A/sec.) 0.2% Ceria-coated Silica pH 5.35 18.8 20.4 20.6 0.2% Ceria-coated Silica + 0.01% GA pH 5.35 3.5 3.5 3.7 0.2% Ceria-coated Silica + 0.01% GA pH 6.0 4.0 4.4 4.4 0.2% Ceria-coated Silica + 0.01% GA pH 7.0 3.7 4.0 4.1
[0156] As the results shown in Table 11 and
[0157] The effects of chemical additive, gluconic acid, used at 0.01 wt. % at different pH conditions in the polishing compositions were also observed on oxide trench dishing vs over polishing times while comparing the polishing results from the reference sample without using gluconic acid as additive. The test results were listed in Table 12,
TABLE-US-00012 TABLE 12 Effects of pH with 0.01% Gluconic Acid % on Oxide Trench Dishing vs OP Times (Sec.) Over Polishing 100 m Pitch 200 m Pitch 1000 m Pitch Compositions Times (Sec.) Dishing Dishing Dishing 0.2% Ceria-coated Silica pH 5.35 0 165 291 1013 60 857 1096 1821 120 1207 1531 2392 0.2% Ceria-coated Silica + 0.01% Gluconic 0 52 182 992 acid, pH 5.35 60 203 355 1158 120 344 494 1301 0.2% Ceria-coated Silica + 0.01% Gluconic 0 47 168 1386 acid, pH 6.0 60 262 389 1618 120 418 577 1794 0.2% Ceria-coated Silica + 0.01% Gluconic 0 65 182 1380 acid, pH 7.0 60 245 372 1575 120 399 552 1753
[0158] As the results shown in Table 12,
Example 4
[0159] In Example 4, gluconic acid, mucic acid or tartaric acid; ceria-coated silica composite particles were used in different compositions. A reference polishing composition without using any chemical additives was also listed. A biocide ranging from 0.0001 wt. % to 0.05 wt. %, and deionized water were also used in al compositions. The tested compositions had same pH of 5.3.
[0160] Removal rates for various film were listed in Table 13.
TABLE-US-00013 TABLE 13 Effects of Ceria-coated Silica Abrasives on Film RR (/min.) TEOS-R HDP-R PECVD SiN-R LPCVD SiN-R Compositions (ang/min) (ang/min) (ang/min) (ang/min) 0.2% Ceria-coated Silica 2718 2180 349 NA 0.2% Ceria-coated Silica + 0.01% 2375 1975 45 39 Gluconic Acid 0.2% Ceria-coated Silica + 0.01% Mucic 2222 2216 46 33 Acid 0.2% Ceria-coated Silica + 0.01% Tartaric 2251 2368 69 35 Acid
[0161] When gluconic acid, mucic acid or tartaric acid was used at 0.01 wt. % with ceria-coated silica as abrasives, PECVD SiN film removal rates were significantly suppressed while comparing to the PECVD SiN film removal rate obtained from the reference polishing composition not using any additive.
[0162] Such results demonstrated that these organic acids with one or two carboxyl group(s) and two or more hydroxyl groups are very effective SiN removal rate suppressing agents.
[0163] Total defect count reduction on polished TEOS and SiN wafers were tested with STI oxide polishing compositions using ceria-coated silica composite particles as abrasives.
[0164] The total defect count comparison results were listed in Table 14.
TABLE-US-00014 TABLE 14 Total Defect Count Comparison of Ceria-Coated Silica Based STI Oxide Polishing Compositions TEOS 0.07 um TEOS 0.13 um LPCVD SiN LPCVD SiN Compositions LPD LPD 0.1 um LPD 0.13 um LPD 0.2% Ceria-coated Silica + 0.01% 3042 915 3426 2666 Gluconic Acid 0.2% Ceria-coated Silica + 0.01% 2244 165 2738 2104 Mucic Acid 0.2% Ceria-coated Silica + 0.01% 1100 106 2890 1855 Tartaric Acid
[0165] As the results shown in Table 14, at the same pH conditions and with same chemical additive of gluconic acid at 0.01 wt. %, the polishing composition of using ceria-coated silica composite particles as abrasives afforded significantly lower total defect counts on both polished TEOS and SiN films.
[0166] The results shown in Table 14 also demonstrated that the polishing compositions using mucic acid or tartaric acid reduced more total defect counts than the polishing composition using gluconic acid on all test wafers.
Example 5
[0167] In Example 5, under same pH conditions, the polishing compositions using gluconic acid, mucic acid or tartaric acid as chemical additive, were tested vs the reference polishing composition without using any chemical additives.
[0168] The tested compositions, pH conditions, HPD film removal rates, P200 trench loss rates and P200 Trench/Blanket Ratios were listed in Table 15.
TABLE-US-00015 TABLE 15 Effects of Chemical Additives on HDP RR, Trench Loss RR & Trench Loss/Blanket Loss Ratio P200 Trench P200 Trench P200 Trench/ HDP RR(/ Compositions Rate (/sec.) Rate (/min.) Blanket Ratio min) 0.2% Ceria-coated Silica 20.4 1224 0.42 2180 0.2% Ceria-coated Silica + 0.01% 4.7 283 0.12 2375 Gluconic Acid 0.2% Ceria-coated Silica + 0.01% Mucic Acid 4.0 240 0.11 2222 0.2% Ceria-coated Silica + 0.01% Tartaric Acid 8.5 512 0.23 2251
[0169] As the results shown in Table 15, under the same pH conditions, the compositions using a chemical additive at same concentrations at 0.01 wt. % offered the similar HDP film removal rates, but significantly reduced trench loss rate and trench loss rate/blanket loss rate ratios comparing with the reference composition without the use of any chemical additive.
[0170] The over polishing times vs the trench dishing were tested. The results were listed in Table 16.
TABLE-US-00016 TABLE 16 Effects of Chemical Additives on OP Times(Sec.) vs Trench Dishing () Blanket HDP Polish Time 100 um pitch 200 um pitch RR Compositions (Sec.) dishing dishing (/min) 0.2% Ceria-coated Silica 0 165 291 2180 60 857 1096 120 1207 1531 0.2% CPOP + 0.01% Gluconic Acid 0 160 336 2375 60 602 552 120 874 741 0.2% CPOP + 0.01% Mucic Acid 0 247 402 2222 60 384 590 120 530 769 0.2% CPOP + 0.01% Tartaric Acid 0 196 350 2251 60 498 775 120 757 1132
[0171] As the results shown in Table 16, under the same pH conditions, the compositions using a chemical additive at same concentrations at 0.01 wt. % offered significantly lower trench dishing when 60 seconds or 120 second over polishing times were applied.
[0172] The results shown in Table 16 also demonstrated that mucic acid or gluconic acid appear to be more effective chemical additives in reducing trench dishing under different over polishing time conditions than tartaric acid as chemical additive in the polishing composition.
[0173] The embodiments of this invention listed above, including the working example, are exemplary of numerous embodiments that may be made of this invention. It is contemplated that numerous other configurations of the process may be used, and the materials used in the process may be elected from numerous materials other than those specifically disclosed.