Precise patterning of diamond films for MEMS application

To apply diamond films in microelectromechanical systems (MEMS), it is necessary to develop suitable techniques to pattern diamond films in micrometer scale. In this paper, three different techniques capable of precise patterning diamond films will be demonstrated. One is to selectively grow diamond films in the desired region by pre-improving the diamond nucleation density in the said region using DC bias-enhanced microwave plasma chemical vapor deposition (MPCVD). Another technique is to selectively grow diamond films in the desired region by seeding the given region using diamond-powder-mixed photoresist. The third technique is to selectively etch large-area diamond film by an oxygen-ion beam under an Al mask. Several diamond-film patterns with a feature size of a few micrometers were successfully fabricated, and some technical problems encountered in the techniques are discussed.