High-Mobility Stable 4H-SiC MOSFETs Using a Thin PSG Interfacial Passivation Layer

Author

Sharma, Yogesh K. ; Ahyi, Ayayi C. ; Isaacs-Smith, T. ; Modic, Aaron ; Park, Mirang ; Xu, Yan ; Garfunkel, E.L. ; Dhar, Sudipta ; Feldman, L.C. ; Williams, John R.

Author_Institution

Phys. Dept., Auburn Univ., Auburn, AL, USA

Volume

34

Issue

2

fYear

2013

fDate

Feb. 2013

Firstpage

175

Lastpage

177

Abstract

Phosphorous from P₂O₅ is more effective than nitrogen for passivating the 4H-SiC/SiO₂ interface. The peak value of the field-effect mobility for 4H-SiC metal-oxide-semiconductor field-effect transistors (MOSFETs) after phosphorus passivation is approximately 80 cm²/V·s. However, P₂O₅ converts the SiO₂ layer to phosphosilicate glass (PSG)-a polar material that introduces voltage instabilities which negate the benefits of lower interface trap density and higher mobility. We report a significant improvement in voltage stability with mobilities as high as 72 cm²/V·s for MOSFETs fabricated with a thin PSG gate layer ( ~ 10 nm) capped with a deposited oxide.

Keywords

MOSFET; hydrogen; phosphorus compounds; silicon compounds; stability; H-SiC-SiO₂; P₂O₅; PSG interfacial passivation layer; high-mobility stable MOSFET; higher mobility; interface trap density; metal-oxide-semiconductor held-effect transistors; phosphorus passivation; phosphosilicate glass; polar material; voltage instability; Annealing; Capacitors; Logic gates; MOSFETs; Passivation; Silicon carbide; Threshold voltage; MOSFET; silicon carbide; stability; thin phosphosilicate glass (PSG);

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2012.2232900

Filename

6407723