TY - JOUR
T1 - Normally-OFF Two-Dimensional Hole Gas Diamond MOSFETs Through Nitrogen-Ion Implantation
AU - Oi, Nobutaka
AU - Kudo, Takuya
AU - Inaba, Masafumi
AU - Okubo, Satoshi
AU - Onoda, Shinobu
AU - Hiraiwa, Atsushi
AU - Kawarada, Hiroshi
N1 - Funding Information:
Manuscript received April 3, 2019; accepted April 11, 2019. Date of publication May 15, 2019; date of current version May 23, 2019. This work was supported in part by the Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for Fundamental Research(S) under Grant 26220903 and in part by the Creation of Life Innovation Materials for Interdisciplinary and International Researcher Development, MEXT, Japan. The review of this letter was arranged by Editor G. Han. (Corresponding author: Hiroshi Kawarada.) N. Oi, T. Kudo, and S. Okubo are with the Faculty of Science and Engineering, Waseda University, Tokyo 169-8555, Japan (e-mail: kawarada@waseda.jp).
Publisher Copyright:
© 1980-2012 IEEE.
PY - 2019/6
Y1 - 2019/6
N2 - 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 \mu \text{m}. 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 nitrogen-ion 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.
AB - 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 \mu \text{m}. 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 nitrogen-ion 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.
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U2 - 10.1109/LED.2019.2912211
DO - 10.1109/LED.2019.2912211
M3 - Article
AN - SCOPUS:85066433574
SN - 0741-3106
VL - 40
SP - 933
EP - 936
JO - IEEE Electron Device Letters
JF - IEEE Electron Device Letters
IS - 6
M1 - 8715486
ER -