SELECTED-AREA DEPOSITION OF DIAMOND FILMS

Selected-area deposition of diamond film has been accomplished on Si substrates prepared by two different methods: reactive-ion etching (RIE) and amorphous-Si masking (ASM). In the RIE method, a Si substrate polished by a diamond paste was patterned with a photoresist mask, and the unprotected areas were etched by RIE, followed by a complete removal of the photoresist films. The diamond deposition was done by electron-assisted chemical-vapor deposition (CVD), and diamond films grew only in the areas once covered with the photoresist films and not etched by RIE. In the ASM method, a polished Si substrate was also photolithographically masked with photoresist, followed by a uniform deposition of a hydrogenated amorphous silicon (a-Si:H) film. The photoresist film was then lifted off together with the overlay of deposited a-Si:H, leaving the polished Si surface patterned with an a-Si:H mask. In this case, the diamond deposition was done by microwave plasma CVD, and diamond films grew only in the areas not covered with a-Si:H. In both cases, well-defined diamond patterns with line/space dimensions of a few micrometers were formed on the substrates.