A New Simple Fabrication Method for Silicon Nanowire-Based Accelerometers

Silicon nanowire (SiNW) has received great attention in sensing applications because of its outstanding piezoresistive (PZR) effects. However, the difficulty of integrating SiNWs and sensor structures has hindered the development of various SiNW-based sensors. This paper presents a new simple, scalable fabrication method for SiNWs and its application to accelerometers. The developed method enables monolithic integration of SiNWs with sensing structures and allows controlling the dimensions of SiNWs and sensor structures independently. Furthermore, the developed method has significantly reduced fabrication complexity when compared to the previous approach by reducing the number of mask layers. In this paper, a SiNW-based PZR accelerometer is fabricated using the developed method, and experiments are performed. Compared to commercial capacitive accelerometers, the presented PZR accelerometer can reduce approximately 36 % of the total area by replacing the comb-type capacitive sensing units by much smaller SiNWs.