Giant piezoresistance effect in p-type silicon

This article presents a study of the giant piezoresistance effect in p-type silicon using full-band Monte Carlo simulation. This effect has been demonstrated experimentally in Si nanowires by He and Yang. By introducing a law of variation of the surface potential according to the applied mechanical stress, we can reproduce this effect. The modulation of the width of the depletion region associated with the variation of surface potential induces a strong modulation of the total amount of carriers available for the conduction, which increases drastically this piezoresistive effect. This is probably the main origin of this effect, which may be used to achieve high performance MEMS sensors.