Microprocessing of synthetic quartz glass substrate

Abstract

In a process for microprocessing a synthetic quartz glass substrate by wet etching, an organic coating layer of silane or silazane is formed on the substrate, and a photoresist film is formed on the organic coating layer, prior to the wet etching.

1 . A process for microprocessing a synthetic quartz glass substrate by wet etching, the substrate including a region to be etched and a region to be mask-protected, the process comprising the steps of:
 forming an organic coating layer on at least the mask-protected region of the substrate, and   forming a photoresist film on the organic coating layer, prior to the wet etching.   
     
     
         2 . The process of  claim 1  wherein the organic coating layer comprises a silazane compound or a compound having the general formula (I):
   R 4-n SiX n   (1)   
       wherein R is each independently a substituted or unsubstituted, straight, branched or cyclic alkyl group of 1 to 18 carbon atoms, aryl or aralkyl group of 6 to 18 carbon atoms, or unsaturated aliphatic hydrocarbon group of 2 to 18 carbon atoms, X is chlorine, methoxy or ethoxy, and n is an integer of 1 to 3. 
     
     
         3 . The process of  claim 1  wherein the wet etching uses an etching liquid containing hydrofluoric acid or a fluoride salt.