Mechanical and piezoresistive properties of diamond-like carbon for MEMS
Diamond-like carbon (DLC) was investigated as structural and functional material for MEMS applications. Integrated into standard bulk silicon micromachining, the processing of DLC benefited from a low deposition temperature, simple patterning by lift-off and an excellent etching resistance. MEMS components were realized and characterized including self-supporting sub-micron thick DLC cantilevers and DLC strain gauges on a silicon boss membrane tactile sensor. DLC cantilevers exhibited a large Young's modulus and fracture strength which can be exploited for MEMS resonators. Gauge factor, noise and thermal drift comparable with doped silicon combined with a very low susceptibility to light were observed with DLC strain gauges offering an extended degree of freedom for the design of rugged silicon sensors.