MEMS sensor with giant piezoresistive effect using metall-semiconductor hybrid structure

The piezoresistance effect of silicon has been widely used in MEMS sensors [1-3]. Strain engineering is now considered to be the one of the most promising strategies for developing high performance sub-10-nm silicon devices [4]. Strain silicon sensors show typically a gauge factor of below 100, depending on temperature, orientation, doping level and stress direction. The magnitude of piezoresistance in single crystal silicon is determined by piezoresistive coefficients (π₁₁, π₁₂, π₄₄). Interesting electromechanical properties have been observed in silicon nanowires [5] and carbon nanotubes [6]. This new materials show an unusual large piezoresistance effect compared with bulk silicon. One of disadvantages of using this new materials is the complicated and expensive manufacturing. In this paper we report on the first realized pressure sensor approach, which uses the proposed metal-semiconductor (silicon) hybrid structures in order to achieve higher K-factor.