Comprehensive Investigation on Electrical Properties of Split-Gate Trench Power MOSFETs Under Mechanical Strains

In this article, we have comprehensively investigated the electrical properties of split-gate trench (SGT) power MOSFETs under mechanical strains. The static and dynamic electrical properties of SGT power MOSFETs under both uniaxial and biaxial strains are examined thoroughly. It is found that both uniaxial and biaxial compressive strains improve the drain current ( ${I}_{d}$ ), while uniaxial and biaxial tensile strains do the opposite. The influence of strain is correlated with drain voltage ( ${V}_{d}$ ), and biaxial strains are slightly more effective than uniaxial strains. The mechanical strains do not change the threshold voltage ( ${V}_{{\mathrm {th}}}$ ), breakdown voltage (BV), capacitances, and switching characteristics. The piezoresistance coefficients of the SGT power MOSFETs are evaluated. It is also proved that both biaxial and uniaxial compressive strains can effectively decrease the figure-of-merit (FOM) of SGT power MOSFETs.