Fully Ion Implanted Normally-Off GaN DMOSFETs with ALD-Al2O3 Gate Dielectrics

Materials

Yuto Ando¹  Hiroshi Amano¹  Tetsu Kachi²  Manato Deki²  Yoshio Honda²  Tohru Nakamura²  Kazuo Kuriyama³  Tomoaki Nishimura³  Michitaka Yoshino³  Toru Toyabe⁴ 

[1] Department of Electrical Engineering and Computer Science, Nagoya University, Nagoya 464-8601, Japan;Institute of Materials and Systems for Sustainability (IMaSS), Nagoya University, Nagoya 464-8603, Japan;Research Center of Ion Beam Technology, Hosei University, Tokyo 184-8584, Japan;Toyo University, Kawagoe 350-8585, Japan;

关键词: GaN;    ion implantation;    Mg;    MOSFET;    Si;   

DOI  :  10.3390/ma12050689

来源: DOAJ

【 摘 要 】

A normally-off GaN double-implanted vertical MOSFET (DMOSFET) with an atomic layer deposition (ALD)-Al₂O₃ gate dielectric film on a free-standing GaN substrate fabricated by triple ion implantation is presented. The DMOSFET was formed with Si ion implanted source regions in a Mg ion implanted p-type base with N ion implanted termination regions. A maximum drain current of 115 mA/mm, maximum transconductance of 19 mS/mm at a drain voltage of 15 V, and a threshold voltage of 3.6 V were obtained for the fabricated DMOSFET with a gate length of 0.4 μm with an estimated p-type base Mg surface concentration of 5 × 10¹⁸ cm⁻³. The difference between calculated and measured V_ths could be due to the activation ratio of ion-implanted Mg as well as Fermi level pinning and the interface state density. On-resistance of 9.3 mΩ·cm² estimated from the linear region was also attained. Blocking voltage at off-state was 213 V. The fully ion implanted GaN DMOSFET is a promising candidate for future high-voltage and high-power applications.

【 授权许可】

Unknown