Roughened substrate support

Abstract

The present invention generally relates to a substrate support for use in a substrate processing chamber. A roughened substrate support reduces arcing within the chamber and also contributes to uniform deposition on the substrate. The roughening can occur in two steps. In a first step, the substrate support is bead blasted to initially roughen the surfaces. Then, the roughened surface is bead blasted with a finer grit to produce a substrate support with a surface roughness of between about 707 micro-inches and about 837 micro-inches. Following the surface roughening, the substrate support is anodized.

1 . A method of forming a roughened substrate support, comprising:
 bead blasting a surface of a substrate support in a first process where the beads have a first grit size; and   bead blasting the surface of the substrate support in a second process where the beads have a second grit size that is smaller than the first grit size.   
     
     
         2 . The method of  claim 1 , wherein the first process comprises delivering the beads from a nozzle to the substrate support and wherein the nozzle is disposed at an angle of between about 85 degrees and 95 degrees relative to the surface of the substrate support. 
     
     
         3 . The method of  claim 2 , wherein the first grit size is between about 23 grit and about 25 grit. 
     
     
         4 . The method of  claim 3 , wherein the nozzle is spaced between about 400 mm and about 600 mm from the surface of the substrate support during the first process. 
     
     
         5 . The method of  claim 4 , wherein the first process further comprises:
 scanning the nozzle across the surface of the substrate support in a first direction;   shifting the nozzle along the surface of the substrate support in a second direction perpendicular to the first direction; and   scanning the nozzle across the surface of the substrate support in a third direction opposite the first direction.   
     
     
         6 . The method of  claim 5 , wherein the shifting comprises moving the nozzle in the second direction for a distance between about 20 mm and about 40 mm. 
     
     
         7 . The method of  claim 1 , wherein the second process comprises delivering the beads from a nozzle to the substrate support and wherein the nozzle is disposed at an angle of between about 85 degrees and 95 degrees relative to the surface of the substrate support. 
     
     
         8 . The method of  claim 7 , wherein the second grit size is between about 58 grit and about 61 grit. 
     
     
         9 . The method of  claim 8 , wherein the nozzle is spaced between about 400 mm and about 600 mm from the surface of the substrate support during the second process. 
     
     
         10 . The method of  claim 9 , wherein the second process further comprises:
 scanning the nozzle across the surface of the substrate support in a first direction;   shifting the nozzle along the surface of the substrate support in a second direction perpendicular to the first direction; and   scanning the nozzle across the surface of the substrate support in a third direction opposite the first direction.   
     
     
         11 . The method of  claim 10 , wherein the shifting comprises moving the nozzle in the second direction for a distance between about 20 mm and about 40 mm. 
     
     
         12 . The method of  claim 11 , wherein the second process further comprises:
 rotating the substrate support 90 degrees counterclockwise;   scanning the nozzle across the surface of the substrate support in the first direction;   shifting the nozzle along the surface of the substrate support in the second direction; and   scanning the nozzle across the surface of the substrate support in the third direction.   
     
     
         13 . The method of  claim 12 , wherein the second process further comprises:
 rotating the substrate support 90 degrees counterclockwise;   scanning the nozzle across the surface of the substrate support in the first direction;   shifting the nozzle along the surface of the substrate support in the second direction; and   scanning the nozzle across the surface of the substrate support in the third direction.   
     
     
         14 . The method of  claim 13 , wherein the second process further comprises:
 rotating the substrate support 90 degrees counterclockwise;   scanning the nozzle across the surface of the substrate support in the first direction;   shifting the nozzle along the surface of the substrate support in the second direction; and   scanning the nozzle across the surface of the substrate support in the third direction.   
     
     
         15 . A method of forming a roughened substrate support, comprising:
 bead blasting a surface of a substrate support in a first process comprising:
 scanning the nozzle across the surface of the substrate support in a first direction; 
 shifting the nozzle along the surface of the substrate support in a second direction perpendicular to the first direction; and 
 scanning the nozzle across the surface of the substrate support in a third direction opposite the first direction; and 
   bead blasting the surface of the substrate support in a second process comprising:
 first scanning the nozzle across the surface of the substrate support in the first direction; 
 shifting the nozzle along the surface of the substrate support in the second direction; 
 second scanning the nozzle across the surface of the substrate support in the third direction; 
 rotating the substrate support about 90 degrees counterclockwise; and 
 repeating the first scanning, shifting, second scanning and rotating. 
   
     
     
         16 . The method of  claim 15 , wherein the repeating occurs three times. 
     
     
         17 . The method of  claim 16 , wherein the first process comprises bead blasting the surface with beads having a grit size of between about 23 grit and about 25 grit. 
     
     
         18 . The method of  claim 17 , wherein the second process comprises bead blasting the surface with beads having a grit size of between about 58 grit and 61 grit. 
     
     
         19 . A substrate support, comprising:
 a substrate support body having a surface roughness of between about 707 micro-inches and about 834 micro-inches; and   an anodized coating on the substrate support.   
     
     
         20 . The substrate support of  claim 19 , wherein the substrate support body comprises aluminum.