NITRIDE INHIBITORS FOR HIGH SELECTIVITY OF TiN-SiN CMP APPLICATIONS
The invention provides a chemical-mechanical polishing composition comprising (a) abrasive particles, b) a removal rate inhibitor selected from (I) a surfactant comprising a polyoxyalkylene functional group and a sulfonate functional group, (II) a surfactant comprising a polyoxyalkylene functional group and a sulfate functional group, (III) a first surfactant comprising a polyoxyalkylene functional group and a second surfactant comprising a sulfonate functional group, and (IV) a first surfactant comprising a polyoxyalkylene functional group and a second surfactant comprising a sulfate functional group, and (c) an aqueous carrier. The invention also provides a method of chemically-mechanically polishing a substrate comprising TiN and SiN with the inventive chemical-mechanical polishing composition.
1 . A chemical-mechanical polishing composition comprising:
(a) alumina particles, wherein the alumina particles have a surface that comprises an anionic polymer,
(b) a removal rate inhibitor selected from (I) a surfactant comprising a polyoxyalkylene functional group and a sulfonate functional group, (II) a surfactant comprising a polyoxyalkylene functional group and a sulfate functional group, (III) a first surfactant comprising a polyoxyalkylene functional group and a second surfactant comprising a sulfonate functional group, and (IV) a first surfactant comprising a polyoxyalkylene functional group and a second surfactant comprising a sulfate functional group, and
(c) an aqueous carrier.
2 . The polishing composition of claim 1 , wherein the alumina particles are present in the polishing composition at a concentration of about 0.001 wt. % to about 10 wt. %.
3 . The polishing composition of claim 1 , wherein the anionic polymer comprises repeating units selected from carboxylic acid functional groups, sulfonic acid functional groups, phosphonic acid functional groups, and combinations thereof
4 . The polishing composition of claim 3 , wherein the anionic polymer comprises repeating units selected from acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, vinyl sulfonic acid, 2-(methacryloyloxy)ethanesulfonic acid, styrene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, vinylphosphonic acid, 2-(methacroyloxy)ethylphosphate, and combinations thereof.
5 . The polishing composition of claim 1 , wherein the removal rate inhibitor is present in the polishing composition at a concentration of about 0.001 wt. % to about 5 wt. %.
6 . The polishing composition of claim 1 , wherein the removal rate inhibitor comprises a polyoxyethylene group.
7 . The polishing composition of claim 1 , wherein the removal rate inhibitor is selected from a surfactant comprising a lauryl polyoxyethylene ether sulfate, a first surfactant comprising ethoxylated C 6 -C 12 alcohols and a second surfactant comprising C 10 -C 14 alkylaryl sulfonates, a first surfactant comprising sulfonated alkyldiphenyloxides and a second surfactant comprising polyoxyethylene sorbitan monolaurate, a first surfactant comprising an alpha-olefin sulfonate and a second surfactant comprising polyoxyethylene sorbitan monolaurate, and combinations thereof.
8 . The polishing composition of claim 7 , wherein the removal rate inhibitor comprises a first surfactant comprising ethoxylated C 6 -C 12 alcohols and a second surfactant comprising C 10 -C 14 alkylaryl sulfonates.
9 . The polishing composition of claim 7 , wherein the removal rate inhibitor comprises a first surfactant comprising sulfonated alkyldiphenyloxides and a second surfactant comprising polyoxyethylene sorbitan monolaurate.
10 . The polishing composition of claim 1 , wherein the polishing composition has a pH of about 1 to about 5.
11 . The polishing composition of claim 1 , further comprising a catalyst or a corrosion inhibitor.
12 . The polishing composition of claim 11 , wherein the polishing composition comprises a corrosion inhibitor, and wherein the corrosion inhibitor is selected from hexylamine, tetramethyl-p-phenylene diamine, octylamine, diethylene triamine, dibutyl benzylamine, aminopropylsilanol, aminopropylsiloxane, dodecylamine, tyrosine, arginine, glutamine, glutamic acid, cystine, lysine, glycine (aminoacetic acid), and combinations thereof.
13 . A method of chemically-mechanically polishing a substrate comprising:
(i) providing a substrate comprising a titanium nitride (TiN) layer on a surface of the substrate and a silicon nitride (SiN) layer on a surface of the substrate;
(ii) providing a polishing pad;
(iii) providing a chemical-mechanical polishing composition comprising:
(a) abrasive particles,
(b) a removal rate inhibitor selected from (I) a surfactant comprising a polyoxyalkylene functional group and a sulfonate functional group, (II) a surfactant comprising a polyoxyalkylene functional group and a sulfate functional group, (III) a first surfactant comprising a polyoxyalkylene functional group and a second surfactant comprising a sulfonate functional group, and (IV) a first surfactant comprising a polyoxyalkylene functional group and a second surfactant comprising a sulfate functional group, and
(c) an aqueous carrier;
(iv) contacting the substrate with the polishing pad and the chemical-mechanical polishing composition; and
(v) moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate to abrade at least a portion of the TiN layer on a surface of the substrate and at least a portion of the SiN layer on a surface of the substrate to polish the substrate, wherein the TiN layer is selectively removed faster than the SiN layer.
14 . The method of claim 13 , wherein the TiN:SiN removal rate selectivity is greater than 15:1.
15 . The method of claim 13 , wherein the abrasive particles are selected from colloidal silica particles and alumina particles, wherein the alumina particles have a surface that comprises an anionic polymer.
16 . The method of claim 15 , wherein the abrasive particles are alumina particles, wherein the alumina particles have a surface that comprises an anionic polymer.
17 . The method of claim 16 , wherein the anionic polymer comprises repeating units selected from acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, vinyl sulfonic acid, 2-(methacryloyloxy)ethanesulfonic acid, styrene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, vinylphosphonic acid, 2-(methacroyloxy)ethylphosphate, and combinations thereof.
18 . The method of claim 13 , wherein the abrasive particles are present in the polishing composition at a concentration of about 0.001 wt. % to about 10 wt. %.
19 . The method of claim 13 , wherein the removal rate inhibitor comprises a polyoxyethylene group.
20 . The method of claim 13 , wherein the removal rate inhibitor is selected from a surfactant comprising a salt of lauryl polyoxyethylene ether sulfate, a first surfactant comprising ethoxylated C 6 -C 12 alcohols and a second surfactant comprising C 10 -C 14 alkylaryl sulfonates, a first surfactant comprising sulfonated alkyldiphenyloxides and a second surfactant comprising polyoxyethylene sorbitan monolaurate, a first surfactant comprising an alpha-olefin sulfonate and a second surfactant comprising polyoxyethylene sorbitan monolaurate, and combinations thereof.
21 . The method of claim 20 , wherein the removal rate inhibitor comprises a first surfactant comprising ethoxylated C 6 -C 12 alcohols and a second surfactant comprising C 10 -C 14 alkylaryl sulfonates.
22 . The method of claim 20 , wherein the removal rate inhibitor comprises a first surfactant comprising sulfonated alkyldiphenyloxides and a second surfactant comprising polyoxyethylene sorbitan monolaurate.
23 . The method of claim 13 , wherein the removal rate inhibitor is present in the polishing composition at a concentration of about 0.001 wt. % to about 5 wt. %.
24 . The method of claim 13 , wherein the polishing composition has a pH of about 1 to about 5.
25 . The method of claim 13 , wherein the polishing compositions further comprises a catalyst or a corrosion inhibitor.
26 . The method of claim 25 , wherein the polishing composition comprises a corrosion inhibitor, and wherein the corrosion inhibitor is selected from hexylamine, tetramethyl-p-phenylene diamine, octylamine, diethylene triamine, dibutyl benzylamine, aminopropylsilanol, aminopropylsiloxane, dodecylamine, tyrosine, arginine, glutamine, glutamic acid, cystine, lysine, glycine (aminoacetic acid), and combinations thereof.