Polishing compositions and methods of use thereof
AssigneeFujifilm Electronic Materials U.S.A., Inc.
InventorsAlexei P. Leonov, Abhudaya Mishra
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Abstract
The disclosure provides chemical mechanical polishing compositions and methods for polishing polysilicon films with high removal rates. The compositions include 1) an abrasive; 2) at least one compound of structure (I): 3) at least one compound of structure (II): and 4) water; in which the composition does not include tetramethylammonium hydroxide or a salt thereof. The variables n, R1-R7, X, Y, and Z1-Z3 in structures (I) and (II) are defined in the Specification. The synergistic effect of the compounds of structures (I) and (II) in these chemical mechanical polishing compositions leads to high polysilicon films material removal rate during polishing.
Claims28
A method for polishing a polysilicon film exposed on the surface of a wafer substrate, comprising treating the polysilicon film with a chemical mechanical polishing composition that comprises:
- 1) at least one abrasive;
- 2) at least one compound of structure (I):
- wherein:
- n is 0, 1, 2, or 3;
- each of X and Y, independently, is O(Ra), CH2(Ra), or NH(Ra), provided that at least one of X and Y is O(Ra) or NH(Ra), in which each Ra, independently, is H or C1-C2 alkyl optionally substituted by hydroxyl or NH2, and
- each of R1-R6, independently, is H, OH, or C1-C3 alkyl optionally substituted by OH or NH2;
- 3) at least one compound of structure (II):
- wherein
- each of Z1 and Z2, independently, is —CR8— or —N—, in which R8 is H, N(Rb)2, COOH, C1-C3 alkyl;
- each Rb, independently, being H or C1-C3 alkyl;
- or Z1 and Z2 together form a 5-6 membered ring fused with the 5-membered ring in Structure (II);
- Z3 is —C— or —N—;
- and
- R7 is H, COOH, C1-C3 alkyl, or N(R9)2, in which each R9, independently, is H or C1-C3 alkyl;
- provided that, when Z3 is —N—, R7 is deleted;
- and
- 4) water;
- wherein the composition does not include tetramethylammonium hydroxide or a salt thereof, the wafer substrate further comprises a silicon nitride film on the surface, and the composition has a polysilicon-to-silicon nitride removal rate ratio of at least about 50:1.
A method for polishing a polysilicon film exposed on the surface of a wafer substrate, comprising treating the polysilicon film with a chemical mechanical polishing composition that comprises:
- 1) at least one abrasive;
- 2) at least one compound of structure (I):
- wherein:
- n is 0, 1, 2, or 3;
- each of X and Y, independently, is O(Ra), CH2(Ra), or NH(Ra), provided that at least one of X and Y is O(Ra) or NH(Ra), in which each Ra, independently, is H or C1-C3 alkyl optionally substituted by hydroxyl or NH2, and each of R1-R6, independently, is H, OH, or C1-C3 alkyl optionally substituted by OH or NH2;
- 3) at least one compound of structure (II):
- wherein
- each of Z1 and Z2, independently, is —N—;
- or Z1 and Z2 together form a 5-6 membered ring fused with the 5-membered ring in Structure (II);
- Z3 is —C—;
- and
- R7 is H, COOH, C1-C3 alkyl, or N(R9)2, in which each R9, independently, is H or C1-C3 alkyl;
- and
- 4) water;
- wherein the composition does not include a tetraalkylammonium salt or tetramethylammonium hydroxide, the wafer substrate further comprises a silicon nitride film on the surface, and the composition has a polysilicon-to-silicon nitride removal rate ratio of at least about 50:1.
A method for polishing a polysilicon film exposed on the surface of a wafer substrate, comprising treating the polysilicon film with a chemical mechanical polishing composition that comprises:
- 1) at least one abrasive comprising colloidal silica;
- 2) at least one compound of structure (I):
- wherein:
- n is 0, 1, 2, or 3;
- each of X and Y, independently, is O(Ra), CH2(Ra), or NH(Ra), provided that at least one of X and Y is O(Ra) or NH(Ra), in which each Ra, independently, is H or C1-C3 alkyl optionally substituted by hydroxyl or NH2, and
- each of R1-R6, independently, is H, OH, or C1-C3 alkyl optionally substituted by OH or NH2;
- 3) at least one compound of structure (II):
- wherein
- each of Z1 and Z2, independently, is —CR8— or —N—, in which R8 is H, N(Rb)2, COOH, C1-C3 alkyl;
- each Rb, independently, being H or C1-C3 alkyl;
- or Z1 and Z2 together form a 5-6 membered ring fused with the 5-membered ring in Structure (II);
- Z3 is —C— or —N—;
- and
- R7 is H, COOH, C1-C3 alkyl, or N(R9)2, in which each R9, independently, is H or C1-C3 alkyl;
- provided that, when Z3 is —N—, R7 is deleted;
- and
- 4) water;
- wherein the composition does not include a tetraalkylammonium salt or tetramethylammonium hydroxide, the wafer substrate further comprises a silicon nitride film on the surface, and the composition has a polysilicon-to-silicon nitride removal rate ratio of at least about 50:1.
Dependencies are inferred from the claim text.