ELECTRON-BEAM ASSISTED CHEMICAL ETCHING OF SINGLE-CRYSTAL DIAMOND SUBSTRATES

Electron beam assisted chemical etching (EBACE) with oxygen gas is app licable to direct fine patterning of single crystal diamond substrates . A scanning electron microscope (SEM) combined with an oxygen gas int roduction system was used for EBACE of diamond. In order to prevent su rface charge-up during etching and SEM observation, a hydrocarbon cont amination layer, which has conductivity and can be deposited during el ectron beam irradiation using oil vapor in a vacuum system, was used. Etching characteristics of single crystal diamond substrates by EBACE with oxygen gas were mainly investigated. It was found by in-situ SEM observation that hole, line and rectangular patterns with several mu m (2) area and sub-mu m depth into the diamond substrates were successfu lly fabricated by EBACE utilizing spot, line and raster scanning modes of the SEM. The depths of holes and rectangular patterns were proport ional to electron beam exposure times. Etched areas of line and rectan gular patterns were larger than scanned area. An etching yield of 1.99 x 10(-2) carbon atoms of diamond per electron has been observed for E BACE using oxygen gas.