Charge-carrier mobility in hydrogen-terminated diamond field-effect transistors
Yosuke Sasama, Taisuke Kageura, Katsuyoshi Komatsu, Satoshi Moriyama, Jun-ichi Inoue, Masataka Imura, Kenji Watanabe, Takashi Taniguchi, Takashi Uchihashi, Yamaguchi Takahide
Abstract
Diamond field-effect transistors (FETs) have potential applications in power electronics and high-output high-frequency amplifications. In such applications, high charge-carrier mobility is desirable for a reduced loss and high-speed operation. We recently fabricated diamond FETs with a hexagonal-boron-nitride gate dielectric and observed a high mobility above 300cm2V−1s−1. In this study, we identify the scattering mechanism that limits the mobility of our FETs through theoretical calculations. Our calculations reveal that dominant carrier scattering is caused by surface charged impurities with a density of ≈1×1012cm−2 and suggest that an increase in mobility over 1000cm2V−1s−1 is possible by reducing these impurities.