SELECTIVE-AREA DEPOSITION OF A-C-H FILMS AS MASKS FOR ANISOTROPIC ETCHING OF CRYSTALLINE SILICON IN AQUEOUS POTASSIUM HYDROXIDE

Amorphous hydrogenated carbon (a-C:H) thin films deposited by r.f. che mical vapor deposition were investigated as a chemically resistant mat erial for masking anisotropic etching of crystalline silicon by aqueou s solution of KOH. Films with thicknesses varying from 50 to 80 nm wer e successfully patterned on silicon slices by the lift-off process. Th en the samples were submitted to one aqueous etchant solution of KOH f or 1 h at a temperature of 78 degrees C. The inspection showed well de fined etching pattern indicating the high chemical resistance of the a -C:H film to the aqueous KOH solution. (C) 1998 Elsevier Science Ltd. All rights reserved.