A Study on the Performance Improvement of GaAs Metamorphic HEMTs Using ICPCVD SiNx Passivation |
Dong-Hwan Kim |
ICPCVD 질화막 Passivation을 이용한 GaAs Metamorphic HEMT 소자의 성능개선에 관한 연구 |
김동환 |
국방과학연구소 |
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Abstract |
In this paper, a novel low-damage silicon nitride passivation for 100nm InAlAs/InGaAs MHEMTs has been developed using remote ICPCVD. The silicon nitride deposited by ICPCVD showed higher quality, higher density, and lower hydrogen concentration than those of silicon nitride deposited by PECVD. In particular, we successfully minimized the plasma damage by separating the silicon nitride deposition region remotely from ICP generation region, typically with distance of 34cm. The silicon nitride passivation with remote ICPCVD has been successfully demonstrated on GaAs MHEMTs with minimized damage. The passivated devices showed considerable improvement in DC characteristics and also exhibited excellent RF characteristics($f_T$of 200GHz).The devices with remote ICPCVD passivation of 50nm silicon nitride exhibited 22% improvement(535mS/mm to 654mS/mm) of a maximum extrinsic transconductance($g_{m.max}$) and 20% improvement(551mA/mm to 662mA/mm) of a maximum saturation drain current ($I_{DS.max}$) compared to those of unpassivated ones, respectively. The results achieved in this work demonstrate that remote ICPCVD is a suitable candidate for the next-generation MHEMT passivation technique. |
Key Words:
Metamorphic HEMT, Remote ICPCVD, Maximum Extrinsic Transconductance($g_{m.max}$), Maximum Saturation Drain Current($I_{DS.max}$), Cutoff Frequency($f_T$), Maximum Oscillation Frequency($f_{max}$) |
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