본 논문에서는 반절연성 GaAs(semi-insulating GaAs) 기판위에 $Al_2O_3$ 절연막이 게이트 절연막으로 이용된 공핍형모드 p-채널 GaAs MOSFET (depletion mode p-channel GaAs MOSFET)를 제조하였다. 반절연성 GaAs 기판위에 $1;{mu}m$의 GaAs 버퍼층(buffer layer), $4000;{AA}$의 p형 GaAs 에피층(epi-layer), $500;{AA}$의 AlAs층, 그리고 $50;{AA}$의 캡층(cap layer)을 차례로 성장시키고 습식열산화시켰으며, 이를 통하여 AlAs층은 완전히 $Al_2O_3$층으로 산화되었다. 제조된 MOSFET의 I-V, $g_m$, breakdown특성 측정을 통하여 AlAs/GaAs epilayer/S I GaAs 구조의 습식열산화는 공핍형 모드 p-채널 GaAs MOSFET를 구현하기에 적합함을 알 수 있다.
In this paper, we present p-channel GaAs MOSFET having $Al_2O_3$ as gate insulator fabricated on a semi-insulating GaAs substrate, which can be operated in the depletion mode. $1;{mu}m$ thick undoped GaAs buffer layer, $4000;{AA}$ thick p-type GaAs epi-layer, undoped $500{AA}$ thick AlAs layer, and $50;{AA}$ thick GaAs cap layer were subsequently grown by molecular beam epitaxy(MBE) on (100) oriented semi-insulating GaAs substrate and this wafer was oxidized. AlAs layer was fully oxidized as a $Al_2O_3$ thin film. The I-V, $g_m$, breakdown charateristics of the fabricated GaAs MOSFET showed that wet thermal oxidation of AlAs/GaAs epilayer/S I GaAs was successful in realizing depletion mode p-channel GaAs MOSFET.
