SiO2/Al2O3栅介质SiC沟槽MOSFET中载流子各向异性输运研究

Effectively characterizing carrier transport in miniaturized SiC trench MOSFETs $\cdot $ with high-permittivity (high- $\boldsymbol {\kappa } \text {)}$ -based dielectrics poses significant challenges. This work employs a simplified and innovative method to experimentally demonstrate anisotropic carrier transport in MOSFETs with low-temperature deposited gate dielectrics. The channel mobility on the ( ${{1}}\overline {{1}}{{00}}\text {)}$ trench sidewall reaches 31.6 cm2/V $\cdot $ s, which is 41% higher than the effective channel mobility of 22.4 cm2/V $\cdot $ s on the tilted ( ${{11}}\overline {{2}}{{0}}\text {)}$ plane. Meanwhile, the critical breakdown electric field of ( ${{1}}\overline {{1}}{{00}}\text {)}$ -faced trench device is 4% higher than that of tilted ( ${{11}}\overline {{2}}\mathbf {{0}}\text {)}$ -faced device. Elemental analysis indicates that the ( ${{1}}\overline {{1}}\mathbf {{00}}\text {)}$ plane effectively inhibits the diffusion of Al and O atoms into the SiC. Then, the Al2O3 layer on the ( ${{1}}\overline {{1}}{{00}}\text {)}$ planes was more densely packed, significantly improving the SiC/dielectric interface quality. These results lay a solid foundation for guiding the interface engineering and performance optimization of high- $\boldsymbol {\kappa }$ Al2O3 dielectrics in miniaturized SiC trench MOSFETs.