Diamond surface micromachining technology

Diamond is a wide bandgap semiconductor material with high mechanical strength and thermal stability, and therefore is an ideal candidate for micro electromechanical devices. In this paper, diamond surface micromachining technology used for fabricating diamond film devices is reported. Boron-doped diamond films were used as structure layer, and polysilicon films were used as sacrificial layer. After dry etching of diamond films using an oxygen-ion beam under an aluminum mask and wet etching of polysilicon films by KOH solution to release the microstructures, diamond-film beam resonators and tuning-fork-like resonators were fabricated. The technical problems encountered in surface micromachining technology are discussed.