Comparison of surface passivation films for reduction of current collapse in AlGaN/GaN high electron mobility transistors

Luo B; Mehandru R; Kim J; Ren F; Gila BP; Onstine AH; Abernathy CR; Pearton SJ; Fitch R; Gillespie J; Jenkins T; Sewell J; Via D; Crespo A; Irokawa Y

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Journal of the Electrochemical Society, Vol.149, No.11, G613-G619, 2002

Comparison of surface passivation films for reduction of current collapse in AlGaN/GaN high electron mobility transistors

Luo B, Mehandru R, Kim J, Ren F, Gila BP, Onstine AH, Abernathy CR, Pearton SJ, Fitch R, Gillespie J, Jenkins T, Sewell J, Via D, Crespo A, Irokawa Y

Three different passivation layers (SiNX, MgO, and Sc2O3) were examined for their effectiveness in mitigating surface-state-induced current collapse in AlGaN/GaN high electron mobility transistors (HEMTs). The plasma-enhanced chemical vapor deposited SiNX produced similar to70-75% recovery of the drain-source current, independent of whether SIH4/NH3 or SiD4/ND3 plasma chemistries were employed. Both the Sc2O3 and MgO produced essentially complete recovery of the current in GaN-cap HEMT structures and similar to80-90% recovery in AlGaN-cap structures. The Sc2O3 had superior long-term stability, with no change in HEMT behavior over 5 months aging.