Stress-induced effects on depletion-layer capacitance of metal–oxide–semiconductor capacitors

Abstract

Depletion-layer capacitance of n-type metal–oxide–semiconductor capacitors is investigated under a uniaxial 〈110〉 stressed condition, by means of a high-frequency sweep measurement at room temperature. Abrupt large shifts of the depletion-layer capacitance by the stress are observed. Gauge factors of the effects are approximately 13–33 at 500 ppm strain, which are almost comparable with the piezoresistance effect, and have an opposite sign in tension and compression. The capacitance shifts could be explained with the intrinsic Fermi level which lifts and drops by a change in the ratio of the density-of-states effective masses of holes to electrons due to the band splitting.