Planarized membrane and methods for substrate processing systems
A method and a system for planarizing a membrane is disclosed. In one aspect, the method includes providing a resilient membrane and planarizing the surface of the membrane with a conditioning tool. The planarized membrane may be used in chemical mechanical planarization of a wafer. The method further includes finishing the surface of a wafer with the planarized membrane.
1. A method for processing a resilient membrane for a substrate carrier, the method comprising:
providing the resilient membrane;
planarizing a surface of the resilient membrane by a membrane conditioning tool to form a planarized resilient membrane;
providing a support plate to support the membrane; and
providing a holding element to hold the membrane to the support plate.
2. The method of claim 1 , wherein the planarizing is performed with the membrane attached to a membrane assembly comprising a support plate and a holding element.
3. The method of claim 2 , wherein the membrane surface is planarized using an abrasive material.
4. The method of claim 3 , wherein the abrasive material is sand.
5. The method of claim 3 , wherein planarizing further comprises introducing one or more chemicals to the surface of the resilient membrane.
6. The method of claim 5 , wherein the one or more chemicals comprise a chemical slurry mixture.
7. The method of claim 6 , wherein planarizing comprises controlling a relative rotation velocity between a plate and the membrane with respect to each other.
8. The method of claim 7 , wherein the rotation velocity is approximately 10 to 500 rotations per minute.
9. A method of planarizing a substrate, comprising:
providing the substrate;
providing a CMP system including a planarized membrane formed with the method of claim 1 ; and
planarizing a surface of the substrate.
10. An apparatus for supporting a substrate, comprising:
a membrane comprising a planarized surface, wherein the membrane is planarized by a membrane conditioning tool to reduce a surface roughness of the membrane;
a support plate configured to support the membrane; and
a holding element configured to hold the membrane to the support plate.
11. The apparatus of claim 10 , further comprising a cavity between the support plate and the membrane.
12. The apparatus of claim 11 , further comprising a ring positioned between the support plate and the membrane and forming an outer perimeter with respect to the cavity.
13. The apparatus of claim 12 , wherein the ring comprises a planarized surface.
14. A substrate carrier comprising the apparatus of claim 13 .
15. A membrane for chemical mechanical planarization, comprising:
a resilient membrane body comprising a substrate facing surface and a carrier facing surface, wherein the substrate facing surface is planarized to have a surface roughness within a predetermined range that increases sealing between the membrane and a wafer.
16. The membrane of claim 15 , wherein the thickness between the planarized substrate facing surface and the carrier facing surface is within a range of approximately 0.005 to 0.100 inches.
17. A system for planarizing the membrane of claim 15 , comprising a membrane conditioning tool.
18. The system of claim 17 , comprising a controller configured to planarize the membrane at a pressure within a range of approximately 0.1 to 10 psi.
19. The system of claim 17 , wherein the surface roughness of the planarized substrate facing surface is substantially uniform over the surface of the resilient membrane body.
20. The apparatus of claim 10 , wherein the predetermined range for the surface roughness of the planarized surface of the membrane substantially prevents the wafer from sticking to the planarized surface from surface tension.
21. The apparatus of claim 10 , wherein an outer diameter of the planarized surface has a lower surface roughness than an inner diameter of the planarized surface.
22. The apparatus of claim 10 , wherein the planarized surface of the membrane has a planarity which, when measured by reflecting light off of the planarized surface at a first angle, a range of second angles of the reflected light are within two degrees of each other.
23. The apparatus of claim 22 , wherein the range of the second angles of the reflected light are within 0.7-1.0 degrees of each other.
24. The apparatus of claim 10 , wherein the surface roughness of the planarized membrane is below a threshold value, and wherein the threshold value is selected such that planarization of the wafer held adjacent to the membrane has a lower non-uniformity after chemical mechanical planarization compared to planarization with a comparative membrane that has not been planarized by the membrane conditioning tool.
25. The apparatus of claim 10 , wherein the planarized surface has a surface roughness within a predetermined range that increases sealing between the membrane and a wafer.
26. A membrane for chemical mechanical planarization, comprising:
a resilient membrane body comprising:
a planarized substrate facing surface with a substrate surface roughness; and
a carrier facing surface, with a carrier surface roughness, wherein the substrate surface roughness is less than the carrier surface roughness.