Accumulation-layer electron mobility in n-channel 4H-SiC MOSFETs

Author

Chatty, K. ; Chow, T.P. ; Gutmann, R.J. ; Arnold, E. ; Alok, D.

Author_Institution

Rensselaer Polytech. Inst., Troy, NY, USA

Volume

22

Issue

5

fYear

2001

fDate

5/1/2001 12:00:00 AM

Firstpage

212

Lastpage

214

Abstract

Accumulation-layer electron mobility in n-channel depletion-mode metal oxide semiconductor field effect transistors (MOSFETs) fabricated in 4H-SiC was investigated using Hall-measurements. The accumulation-layer mobility showed a smooth transition from the bulk value (/spl sim/350 cm/sup 2//V-s) in the depletion regime into accumulation (/spl sim/200 cm/sup 2//V-s). In contrast, the field-effect mobility, extracted from the transconductance, was found to be much lower (/spl sim/27 cm/sup 2//V-s), due to the trapping of the field-induced carriers by interface states. Though the current in depletion/accumulation-mode MOSFETs can be high due to the contribution of bulk conduction resulting in low on-resistance, carrier trapping will cause the transconductance to be low in the accumulation regime.

Keywords

accumulation layers; electron mobility; interface states; power MOSFET; semiconductor device measurement; semiconductor materials; silicon compounds; 4H-SiC MOSFETs; Hall-measurements; NMOSFET; SiC; accumulation-layer electron mobility; bulk conduction; depletion-mode; field-effect mobility; field-induced carrier trapping; interface states; n-MOSFETs; n-channel MOSFETs; on-resistance; transconductance; Annealing; Argon; Electron mobility; Electron traps; Implants; Interface states; MOSFETs; Oxidation; Temperature; Transconductance;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/55.919232

Filename

919232