Polishing composition for semiconductor processing, method for preparing polishing composition, and method for manufacturing semiconductor element to which polishing composition is applied
The present invention relates to a polishing composition for a semiconductor process, a method of preparing the polishing composition, and a method of fabricating a semiconductor device using the polishing composition. The polishing composition for a semiconductor process may be applied to a process of polishing an amorphous carbon layer, may exhibit a high removal rate of the amorphous carbon layer, may prevent the occurrence of defects by preventing carbon residue from being re-adsorbed onto a semiconductor substrate during the polishing process, and has excellent storage stability. The present invention may also provide a method of fabricating a semiconductor device using the polishing composition for a semiconductor process.
1 . A polishing composition for a semiconductor process containing abrasive particles, an accelerator, and a stabilizer,
wherein the accelerator comprises cerium salts; and
the stabilizer is an amino acid
wherein the amino acid is selected from the group consisting of arginine, histidine, lysine, aspartic acid, glutamic acid, glutamine, cysteine, proline, asparagine, threonine, alanine, glycine, valine, leucine, isoleucine, and mixtures thereof,
wherein the polishing composition comprises 1 wt % to 2 wt % of the stabilizer, and
the accelerator and the stabilizer are contained at a weight ratio of 0.5:1 to 3:1,
wherein the polishing composition having a polishing performance reduction rate (PPR) of 0% to 60% as calculated by Equation 1 below:
PPR
=
A
0
-
A
1
A
O
×
100
[
Equation
1
]
wherein
A0 is a removal rate measured after performing a polishing process on an amorphous carbon layer (ACL) having a thickness of 2,000 Å for 60 seconds using the polishing composition under the following polishing conditions: a polishing pressure of 2 psi, a carrier rotation speed of 87 rpm, a platen rotation speed of 93 rpm, and a feed flow rate of the polishing composition of 200 ml/min; and
A1 is a removal rate measured after performing the polishing process on the ACL for 60 seconds using the polishing composition under the polishing conditions after keeping the polishing composition at a temperature of 60° C. for 40 hours and cooling the polishing composition at 20 to 25° C.
2 . The polishing composition of claim 1 , wherein the accelerator further comprises one or more from the group consisting of anionic molecules, anionic polymers, hydroxyl acids, and amino acids.
3 . The polishing composition of claim 1 , wherein the abrasive particles are selected from the group consisting of metal oxide particles, organic particles, organic-inorganic composite particles, and mixtures thereof.
4 . The polishing composition of claim 1 , further comprising a surfactant and a pH adjusting agent.
5 . A method for preparing the polishing composition for a semiconductor process of claim 1 , the method comprising steps of:
a) preparing a polishing solution by mixing the stabilizer and the accelerator in a solvent;
b) adjusting a pH of the polishing solution to 2 to 5 by adding a pH adjusting agent to the polishing solution; and
c) mixing a surfactant and the abrasive particles with the polishing solution having a pH of 2 to 5.
6 . The method of claim 5 , wherein step a) comprises:
preparing a mixed solution by mixing the stabilizer with the solvent; and
preparing the polishing solution by mixing the mixed solution with the accelerator.
7 . A method of fabricating a semiconductor, the method comprising steps of:
1) providing a polishing pad comprising a polishing layer;
2) supplying the polishing composition of claim 1 for a semiconductor process to the polishing pad; and
3) polishing a polishing target while allowing the polishing target and the polishing pad to rotate relative to each other so that a polishing-target surface of the polishing target comes into contact with a polishing surface of the polishing layer.