Title :
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
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);
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2012.2232900
