Cleaning process and apparatus for silicate materials
View Patent ↗A method for treating a surface of a quartz substrate includes preparing a substrate to provide a working surface having an initial roughness; and then ultrasonically acid-etching the working surface to increase the roughness of the working surface by at least about 10%. In one embodiment, the initial surface roughness is greater than about 10 Ra, and in another embodiment the initial surface roughness is greater than about 200 Ra. In a still further embodiment, the initial surface area, if less than about 200 Ra, is increased to greater than about 200 Ra. In other embodiments of the present invention, the working surface roughness is increased by at least about 25% or at least about 50%. Simultaneous with the increase in surface area (as measured by the roughness), the surface defects are reduced to reduce particulate contamination from the substrate.
1. A method for treating a working surface of a quartz semiconductor manufacturing substrate comprising:
preparing a quartz semiconductor manufacturing substrate to provide a working surface having an initial working surface roughness;
ultrasonically acid-etching said working surface to increase said initial working surface roughness of said working surface by at least about 10%; and
grit blasting said working surface after ultrasonically acid-etching said working surface with a fine grit having a mesh size greater than about 100.
2. A method for treating said working surface of said quartz semiconductor manufacturing substrate as recited in claim 1 wherein said fine grit has a mesh size greater than about 200.
3. A method for treating said working surface of said quartz semiconductor manufacturing substrate as recited in claim 1 wherein said acid-etching is a first acid-etching and further comprising a second acid-etching of said working surface after fine grit blasting said working surface.
4. A method for treating said working surface of said quartz semiconductor manufacturing substrate as recited in claim 3 wherein said first acid-etching removes substantially more material from said working surface than said second acid-etching.