@article{oai:repo.qst.go.jp:00077674,
 author = {Oi, Nobutaka and Kudo, Takuya and Inaba, Masafumi and Okubo, Satoshi and Onoda, Shinobu and Hiraiwa, Atsushi and Kawarada, Hiroshi and Shinobu, Onoda},
 issue = {6},
 journal = {IEEE Electron Device Letters},
 month = {May},
 note = {Diamond is a promising material for power applications owing to its excellent physical properties. Two-dimensional hole gas (2DHG) diamond metal-oxide- semiconductor field-effect transistors (MOSFETs) with hydrogen-terminated (C-H) channel have high current densities and high breakdown fields but often show normally-ON operation. From the viewpoint of safety, normally-OFF operation is required for power applications. In this letter, we used ion implantation to form a shallow and thin nitrogen-doped layer below the C-H channel region, which realized normally-OFF operation. Nitrogen-ion implanted length is fixed at 5 or 10 μm. Nitrogen is a deep donor (1.7 eV) and the nitrogen-doped layer prevents hole accumulation near the surface. The threshold voltage was as high as -2.5 V and no obvious dependence on the threshold voltage of nitrogenion implanted length is observed. The breakdown field was 2.7 MV/cm at room temperature. Of 64 devices with a common gate length, 75% showed normally-OFF operation. We confirmed the threshold voltage shift by a thin and shallow nitrogen-doped layer formed by ion implantation.},
 pages = {933--936},
 title = {Normally-OFF Two-Dimensional Hole Gas Diamond MOSFETs Through Nitrogen-Ion Implantation},
 volume = {40},
 year = {2019}
}