Composition for polishing semiconductor layers
View Patent ↗An aqueous polishing composition comprises a corrosion inhibitor for limiting removal of an interconnect metal with an acidic pH. The composition includes an organic-containing ammonium salt formed with R 1 , R 2 , R 3 and R 4 are radicals, R 1 has a carbon chain length of 2 to 15 carbon atoms. The organic-containing ammonium salt has a concentration that accelerates TEOS removal and decreases removal of at least one coating selected from the group consisting of SiC, SiCN, Si 3 N 4 and SiCO.
1. An aqueous polishing composition comprising:
a corrosion inhibitor for limiting removal of an interconnect metal;
an acidic pH;
abrasive particles; and
an organic-containing ammonium salt formed with
R 1 , R 2 , R 3 and R 4 are radicals, R 1 is an unsubstituted aryl, alkyl, aralkyl, or alkaryl group that has a carbon chain length of 2 to 15 carbon atoms and the organic-containing ammonium salt has a concentration that accelerates TEOS removal and decreases removal of at least one coating selected from the group consisting of SiC, SiCN, Si 3 N 4 and SiCO with at least one polishing pressure less than 21.7 kPa.
2. The composition of claim 1 , wherein R 1 has 2 to 5 carbon atoms.
3. The composition of claim 1 , wherein the ammonium salt is formed with a compound selected from tetraethyl ammonium, tetrabutylammonium, benzyltributylammonium, benzyltrimethylammonium, benzyltriethylammonium, diallyldimethylammonium, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate, metbacryloyloxyethyltrimethylammonium, 3-(methacrylamido) propyltrimethylammonium, triethylenetetramine, tetramethylguanidine, hexylamine and mixtures thereof.
4. An aqueous polishing composition comprising, by weight percent:
0.05 to 15 abrasive particles;
0 to 10 oxidizing agent;
0.0025 to 6 a corrosion inhibitor for limiting removal of an interconnect metal;
a pH of less than 5; and
0.001 to 3 organic-containing ammonium salt formed with
R 1 , R 2 , R 3 and R 4 are radicals, R 1 is an unsubstituted aryl, alkyl, aralkyl, or alkaryl group that has a carbon chain length of 2 to 15 carbon atoms and the organic-containing ammonium salt has a concentration that accelerates TEOS removal and decreases removal of at least one coating selected from the group consisting of SiC, SiCN, Si 3 N 4 and SiCO with at least one polishing pressure less than 21.7 kPa.
5. The composition of claim 4 , wherein the abrasive comprises a silica, the oxidizing agent comprises hydrogen peroxide, the corrosion inhibitor comprises benzotriazole and the composition has a pH of less than 3 and an organic fluoride ammouium salt.
6. The composition of claim 5 , wherein the polishing composition has a pH of 2 to 3 adjusted with nitric acid.
7. The composition of claim 4 , wherein R 1 has a carbon chain length of 2 to 5.
8. An aqueous polishing composition comprising, by weight percent:
0.1 to 10 silica particles;
0 to 10 oxidizing agent;
0.25 to 4 benzotriazole;
a pH of 1.5 to 4 adjusted with an inorganic adjusting agent; and
0.02 to 2 organic-containing ammonium salt selected from at least one of tetraethyl ammonium salts, tetrabutylammonium salts, benzyltributylammonium salts, benzyltrimethylammonium salts and benzyltriethylammonum salts.
9. The composition of claim 8 , wherein the organic-containing inorganic salt is a tetrabutylamonium salt.
10. The composition of claim 8 , wherein the polishing composition has a pH of 2 to 3 adjusted with nitric acid.