High channel mobility in normally-off 4H-SiC buried channel MOSFETs

Author

Harada, S. ; Suzuki, S. ; Senzaki, J. ; Kosugi, R. ; Adachi, K. ; Fukuda, K. ; Arai, K.

Author_Institution

Japa, Ultra-Low-Loss Power Device Technol. Res. Body & Electrotech. Lab., Tsukuba, Japan

Volume

22

Issue

6

fYear

2001

fDate

6/1/2001 12:00:00 AM

Firstpage

272

Lastpage

274

Abstract

We have fabricated buried channel (BC) MOSFETs with a thermally grown gate oxide in 4H-SiC. The gate oxide was prepared by dry oxidation with wet reoxidation. The BC region was formed by nitrogen ion implantation at room temperature followed by annealing at 1500/spl deg/C. The optimum doping depth of the BC region has been investigated. For a nitrogen concentration of 1×10/sup 17/ cm/sup -3/, the optimum depth was found to be 0.2 μm. Under this condition, a channel mobility of 140 cm²/Vs was achieved with a threshold voltage of 0.3 V. This channel mobility is the highest reported so far for a normally-off 4H-SiC MOSFET with a thermally grown gate oxide.

Keywords

annealing; buried layers; carrier mobility; doping profiles; ion implantation; oxidation; power MOSFET; silicon compounds; wide band gap semiconductors; 0.3 V; 1500 C; SiC-SiO/sub 2/; annealing; dry oxidation; high channel mobility; high-power switching device; nitrogen ion implantation; normally-off 4H-SiC buried channel MOSFETs; optimum doping depth; room temperature; thermally grown gate oxide; threshold voltage; wet reoxidation; Doping; Electron mobility; Ion implantation; Laboratories; MOSFETs; Nitrogen; Oxidation; Research and development; Temperature; Threshold voltage;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/55.924839

Filename

924839