Methods for applying a blanket polymer coating to a substrate
Described are techniques for applying a cured polymeric blanket coating onto a surface, specifically for applying a blanket-coated cured polymeric coating onto a surface of a substrate that is useful as an electrostatic chuck for processing semiconductor wafers.
1. A method of applying a blanket-coated polymeric coating to a surface of an electrostatic chuck, the method comprising:
applying a solution to the surface of the electrostatic chuck to form a solution coating over the entire surface, the solution comprising a radiation-curable polymer;
exposing the entire surface of the solution coating to radiation to form a radiation-cured polymer coating; and
heating the radiation-cured polymer coating to an elevated temperature to remove solvent from the radiation-cured polymer coating,
wherein heating the radiation-cured polymer coating comprises heating the radiation-cured polymer coating to a temperature in a range from 150 to 400 degrees Celsius, for a time of at least 45 minutes.
2. The method of claim 1 , wherein the radiation-curable polymer comprises radiation-curable epoxy polymer.
3. The method of claim 2 , wherein a spray solution comprises at least 75 weight percent organic solvent.
4. The method of claim 2 , wherein the solution has a viscosity in a range from 3 to 9 centipoise when applied to a ceramic surface.
5. The method of claim 1 , wherein the surface is at a temperature below 30 degrees Celsius when applying the solution to the surface.
6. The method of claim 1 , further comprising applying the solution to the surface by multiple paths, with each path passing over the surface in an end-to-end direction, with all paths moving in the same end-to-end direction.
7. The method of claim 1 , further comprising:
applying the solution to the entire surface; and
exposing the entire surface of the solution coating to radiation to form a radiation-cured polymer coating;
without heating the surface during or between the applying and the exposing.
8. The method of claim 1 , further comprising applying the solution coating at a thickness in a range from 3 to 5 microns.
9. The method of claim 1 , wherein the surface of the electrostatic chuck consists essentially of ceramic.
10. The method of claim 1 , wherein the surface of the electrostatic chuck consists of ceramic.
11. The method of claim 1 , wherein the surface comprises:
a ceramic main field,
ceramic protrusions extending vertically from the main field, and
a continuous ceramic circumferential seal at an outer region of the main field.
12. The method of claim 1 , wherein the surface has a roughness in a range from 0.01 to 10 microns Ra.
13. The method of claim 1 , wherein the radiation-curable polymer is conductive.
14. A method of applying a blanket-coated polymeric coating to a surface of an electrostatic chuck, the method comprising:
applying a solution to the surface of the electrostatic chuck to form a solution coating over the entire surface, the solution comprising a radiation-curable polymer, wherein applying the solution to the surface uses multiple paths, with each path passing over the surface in an end-to-end direction, with all paths moving in the same end-to-end direction;
exposing the entire surface of the solution coating to radiation to form a radiation-cured polymer coating; and
heating the radiation-cured polymer coating to an elevated temperature to remove solvent from the radiation-cured polymer coating.
15. The method of claim 14 , wherein the surface of the electrostatic chuck consists essentially of ceramic.
16. The method of claim 14 , further comprising applying the solution coating at a thickness in a range from 3 to 5 microns.
17. A method of applying a blanket-coated polymeric coating to a surface of an electrostatic chuck, the method comprising:
applying a solution to the surface of the electrostatic chuck to form a solution coating over the entire surface, the solution comprising a radiation-curable polymer;
exposing the entire surface of the solution coating to radiation to form a radiation-cured polymer coating; and
heating the radiation-cured polymer coating to an elevated temperature to remove solvent from the radiation-cured polymer coating,
wherein the surface comprises:
a ceramic main field,
ceramic protrusions extending vertically from the main field, and
a continuous ceramic circumferential seal at an outer region of the main field.
18. The method of claim 17 , wherein the surface has a roughness in a range from 0.01 to 10 microns Ra.
19. The method of claim 17 , further comprising applying the solution coating at a thickness in a range from 3 to 5 microns.