Chemical mechanical polishing composition having chemical additives and methods for using same
View Patent ↗Chemical-mechanical polishing (CMP) compositions containing chemical additives and methods of using the CMP compositions are disclosed. The CMP composition comprises abrasive; chemical additive; liquid carrier; optionally an oxidizing agent; a pH buffering agent and salt; a surfactant and a biocide. The CMP compositions and the methods provide enhanced removing rate for “SiC”, SiN” and “SiC x N y ” films; and tunable removal selectivity for “SiC” in reference to SiO 2 , “SiN” in reference to SiO 2 , “SiC” in reference to “SiN”, or “SiC x N y ” in reference to SiO 2 ; wherein x ranges from 0.1 wt % to 55 wt %, y ranges from 0.1 wt % to 32 wt %.
1. A chemical mechanical polishing composition consisting of:
a) about 0.05 weight % to 30 weight % abrasive;
b) about 0.025 weight % to about 5 weight % chemical additive;
c) about 0.0001 weight % to about 0.03 weight % of a biocide;
d) about 0.0 weight % to about 2.0 weight % of a pH buffering agent;
e) optionally about 0.0001 weight % to about 1 weight % of a surfactant selected from the group consisting of ethoxylated saturated and unsaturated alcohols; and
f) remaining is substantially liquid carrier;
wherein
the pH buffering agent used to lower the pH of the composition is selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, tartaric acid, succinic acid, citric acid, malic acid, malonic acid, fatty acid, polycarboxylic acid, and mixtures thereof; and
the pH buffering agent used to raise the pH of the composition is selected from the group consisting of potassium hydroxide, sodium hydroxide, ammonia, and mixtures thereof;
the chemical additive is a substituted 4-morpholine derivative having a general molecular structure of:
wherein R is selected from the group consisting of alkyl, alkoxy, substituted 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, and combinations thereof; and
pH of the chemical mechanical polishing composition is from about 2.0 to about 8.
2. The composition of claim 1 , wherein the chemical additive is the substituted 4-morpholine derivative selected from the group consisting of 3-(N-Morpholino)propanesulfonic acid (MOPS), 4-Morpholineethanesulfonic acid (MES), β-Hydroxy-4-morpholinepropanesulfonic acid (MOPSO), and combinations thereof.
3. The composition of claim 1 , wherein the chemical derivative is 3-(N-Morpholino)propanesulfonic acid (MOPS).
4. The composition of claim 1 , wherein the abrasive is selected from the group consisting of alumina, ceria, germania, silica, aluminum-doped silica, titania, zirconia, and mixtures thereof; and the liquid carrier is deionized water.
5. The composition of claim 1 , wherein the chemical derivative is β-Hydroxy-4-morpholinepropanesulfonic acid (MOPSO).
6. The composition of claim 1 , wherein the chemical derivative is 4-Morpholineethanesulfonic acid (MES).
7. A method of a selective chemical mechanical polishing comprising steps of:
a) providing a semiconductor substrate having a surface containing a first material and at least one second material;
b) providing a polishing pad;
c) providing a chemical mechanical polishing composition consisting of:
1) about 0.05 weight % to about 30 weight % abrasive;
2) about 0.025 weight % to 5.0 weight % chemical additive;
3) about 0.0001 weight % to about 0.03 weight % of a biocide;
4) about 0.0 weight % to about 2.0 weight % of a pH buffering agent;
5) optionally about 0.0001 weight % to about 1 weight % of a surfactant selected from the group consisting of ethoxylated saturated and unsaturated alcohols; and
6) remaining is substantially liquid carrier;
wherein the chemical additive is a substituted 4-morpholine derivative having a general molecular structure of:
wherein R is selected from the group consisting of alkyl, alkoxy, substituted 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, and combinations thereof; and
pH of the chemical mechanical polishing composition is from about 2.0 to about 8;
d) contacting the surface of the semiconductor substrate with the polishing pad and the chemical mechanical polishing composition; and
e) polishing the surface of the semiconductor substrate to selectively remove the first material;
wherein at least a portion of the surface containing the first material is in contact with both the polishing pad and the chemical mechanical polishing composition;
ratio of removal rate of the first material to removal rate of the second material is equal to or greater than 1.
8. The method of claim 7 , wherein the substituted 4-morpholine derivative is selected from the group consisting of 3-(N-Morpholino)propanesulfonic acid (MOPS), 4-Morpholineethanesulfonic acid MES), and combinations thereof.
9. The method of claim 7 , wherein the chemical derivative is 3-(N-Morpholino)propanesulfonic acid (MOPS).
10. The method of claim 7 , wherein the abrasive is selected from the group consisting of alumina, ceria, germania, silica, aluminum-doped silica, titania, zirconia, and mixtures thereof; and the liquid carrier is deionized water.
11. The method of claim 7 , wherein
the first material is “SiC x N y ”; and
the second material is selected from the group consisting of SiO 2 and “SiN”;
wherein x ranges from 0.0 wt % to 55 wt %, y ranges from 0.0 wt % to 32 wt %; x and y are not 0 at the same time and
the first material and the second material are different materials.
12. The method of claim 7 , wherein
the first material is “SiC” and the second material is SiO 2 or “SiN”; or
the first material is “SiN” and the second material is SiO 2 .