Piezoresistive microphone with integrated amplifier realized using metal-induced laterally crystallized polycrystalline silicon

Compared to conventional polycrystalline silicon (poly-Si), re-crystallized (RC) metal-induced laterally crystallized (MILC) poly-Si possesses improved mechanical and electrical properties. RC-MILC poly-Si piezoresistors exhibit /spl sim/25% increase in gauge factor and /spl sim/50% reduction in noise level compared to conventional poly-Si piezoresistors. RC-MILC poly-Si transistors exhibit performance approaching those built on single-crystal silicon. As a demonstration of the feasibility of using the RC-MILC poly-Si technology to realize non-trivial micro-systems, microphone integrating piezoresistive strain sensors and amplifiers has been designed, fabricated and characterized.