Laser texturing of ceramic-containing articles

Abstract

A laser texturing process modifies the surface of a semiconductor wafer-handling device so that flatness is maintained, but controlled roughness is imparted to prevent unwanted wafer sticking. The laser texturing may be from a thermal laser, a cold ablation laser, or either laser modified with an inert cover gas. The laser etches or burns away a portion or fraction of a flat surface, thereby reducing the area of contact to the semiconductor wafer and thereby reducing friction and sticking. The etched or burned-away portion is thus at a reduced, relieved or lower elevation than the unaffected portion. The laser texturing may take the form of a plurality of channels cut into the surface, or a plurality of holes. Laser machining can yield a semiconductor wafer handling device having finer detail than can be produced by other shaping techniques, with feature sizes on the order of 50 microns being achievable.

1 - 31 . (canceled) 
     
     
         32 . An extremely flat, machined article of controlled roughness configured as a component for handling semiconductor wafers, comprising:
 (a) a chuck having a support surface;   (b) wherein said support surface features a ceramic-containing material having (i) a first portion at a first elevation, said first portion being optically flat, and (ii) a second portion at a second elevation recessed or relieved with respect to said first elevation, thereby reducing optical contact bonding;   (c) wherein said second portion includes at least two sets of parallel grooves or channels that are angled with respect to one another to form a cross-hatched pattern on said support surface; and   (d) said second portion exhibiting no visible surface oxidation.   
     
     
         33 . The article of  claim 32 , wherein said parallel grooves or channels are no more than 500 microns in width. 
     
     
         34 . The article of  claim 32 , wherein said parallel grooves or channels are spaced no more than 500 microns apart. 
     
     
         35 . The article of  claim 32 , wherein said second portion of said support surface is made by laser machining. 
     
     
         36 . The article of  claim 32 , wherein said component comprises at least one member selected from the group consisting of vacuum wafer chuck, electrostatic chuck, vacuum wafer table, wafer arm, end effector, and susceptor. 
     
     
         37 . The article of  claim 34 , wherein said parallel grooves or channels are spaced no more than 100 microns apart. 
     
     
         38 . The article of  claim 32 , wherein the no visible oxidation is determined using optical or scanning electron microscopy. 
     
     
         39 . The article of  claim 32 , wherein said component includes a wafer chuck populated with a plurality of pins. 
     
     
         40 . The article of  claim 39 , wherein each of said plurality of pins features a top surface, wherein said top surfaces collectively define said first portion, and further wherein said second portion is present on at least one top surface of at least one pin of said plurality of pins. 
     
     
         41 . The article of  claim 32 , wherein said second portion of said support surface has a roughness of at least about 0.75 micron R A . 
     
     
         42 . The article of  claim 32 , wherein said second portion of said support surface exhibits no melted texture. 
     
     
         43 . The article of  claim 32 , wherein said second portion of said support surface exhibits no evidence of microstructural modification. 
     
     
         44 . The article of  claim 32 , wherein said ceramic-containing material has an electrical resistivity greater than about 1×10 6  (10E6) ohm-cm. 
     
     
         45 . The article of  claim 32 , wherein said ceramic-containing material is exclusive of ceramic oxides. 
     
     
         46 . The article of  claim 32 , wherein said ceramic-containing material comprises silicon carbide. 
     
     
         47 . The article of  claim 32 , wherein said channel has a depth of at least 1 micron. 
     
     
         48 . An extremely flat, machined article of controlled roughness, comprising:
 (a) a chuck having a support surface;   (b) wherein said support surface features a ceramic-containing material having (i) a first portion at a first elevation, said first portion being optically flat, and (ii) a second portion at a second elevation recessed or relieved with respect to said first elevation, thereby reducing optical contact bonding;   (c) wherein said second portion includes at least two sets of parallel grooves or channels that are angled with respect to one another to form a cross-hatched pattern on said support surface; and   (d) said second portion exhibiting no visible surface oxidation.   
     
     
         49 . The article of  claim 48 , configured as a component for conditioning a chemical-mechanical planarization pad. 
     
     
         50 . The article of  claim 48 , wherein said support surface comprises at least one material selected from the group consisting of diamond and silicon carbide. 
     
     
         51 . The article of  claim 48 , wherein at least said support surface comprises titanium, silicon, and silicon carbide.