Carbonation of pH controlled KOH solution for improved polishing of oxide films on semiconductor wafers
View Patent ↗A method and polishing system for planarizing a substrate having one or more materials formed thereon. The method generally includes positioning the substrate in proximity with a polishing pad, dispensing a polishing fluid to the polishing pad, the polishing fluid being subjected to carbonation prior to being dispensed to the polishing pad, and polishing the substrate. The polishing system generally includes a polishing platen having a polishing pad disposed thereon and in proximity to the substrate, a controller configured to cause the polishing pad to contact the substrate, and a polishing fluid delivery system to deliver a polishing fluid to the polishing pad, the polishing fluid delivery system including a carbonation system.
1. A method of planarizing a substrate having one or more materials formed thereon, comprising:
positioning the substrate in proximity with a polishing pad;
dispensing a polishing fluid to the polishing pad, the polishing fluid being subjected to carbonation prior to being dispensed to the polishing pad; and
polishing the substrate.
2. The method of claim 1 , wherein the polishing pad is a fixed abrasive polishing pad.
3. The method of claim 2 , wherein the fixed abrasive polishing pad comprises a web.
4. The method of claim 1 , wherein the polishing fluid comprises a pH adjusting agent.
5. The method of claim 4 , wherein the pH adjusting agent is potassium hydroxide.
6. The method of claim 1 , wherein the polishing fluid comprises a buffer compound.
7. The method of claim 1 , wherein the polishing fluid has a pH of from about 7 to about 12.
8. The method of claim 1 , wherein the polishing fluid has a pH of from about 9.5 to about 11.5.
9. The method of claim 1 , wherein the polishing fluid is carbonated for a time from about 5 to about 1000 seconds.
10. The method of claim 1 , wherein the polishing fluid is carbonated for a time from about 100 to about 650 seconds.
11. The method of claim 1 , wherein the substrate has a first dielectric material and a second dielectric material formed thereon.
12. The method of claim 11 , wherein the first dielectric material comprises an oxide.
13. The method of claim 12 , wherein the second dielectric material comprises a nitride.
14. A method of planarizing a substrate having one or more materials formed thereon, comprising:
positioning the substrate in proximity with a fixed abrasive polishing pad;
dispensing a polishing fluid to the fixed abrasive polishing pad, the polishing fluid comprising potassium hydroxide and having a pH of from about 9.5 to about 11.5 and being subjected to carbonation for about 5 to about 1000 seconds prior to being dispensed to the fixed abrasive polishing pad; and
polishing the substrate.
15. The method of claim 14 , wherein the polishing fluid is subjected to carbonation for a time from about 100 to about 650 seconds.
16. A polishing fluid for a fixed abrasive polishing pad configured to remove materials formed on a substrate surface, comprising:
potassium hydroxide;
deionized water; and
carbon dioxide.
17. The polishing fluid of claim 16 , wherein the polishing fluid has a pH of from about 7 to about 12.
18. A polishing system for planarizing one or more materials formed on a substrate surface, comprising:
a polishing platen having a polishing pad disposed thereon and in proximity to the substrate;
a controller configured to cause the polishing pad to contact the substrate; and
a polishing fluid delivery system adapted to deliver a polishing fluid to the polishing pad, the polishing fluid delivery system including a carbonation system.
19. The polishing system of claim 18 , wherein the carbonation system is a bubbling apparatus.
20. The polishing system of claim 19 , wherein the bubbling apparatus is operably connected to a gas regulator configured to control a gas flowrate into the polishing fluid.