| 학회 | 한국재료학회 |
| 학술대회 | 2016년 봄 (05/18 ~ 05/20, 여수 디오션리조트 ) |
| 권호 | 22권 1호 |
| 발표분야 | A. 전자/반도체 재료 분과 |
| 제목 | NH3 Pre-Plasma Treatment to Reduce Interface State Density of GaN MOS Device |
| 초록 | GaN is known to be strong candidate material for power device applications due to its wide bandgap, high thermal conductivity and breakdown voltage. However, Ga and N elements are susceptible to be dissociated during post thermal processing, leading to device performance degradation. In particular, interface between GaN and dielectric could be significantly affected by this dissociation event. Thus, many attempts to passivate GaN interface have been reported using various chemical treatment (HF, HCl, NH4OH, BOE, and (NH4)2Sx) or plasma treatment (N2, H2, NH3). Beside interface passivation, alternative deposited dielectrics including Al2O3, TiO2, and HfO2 are investigated in parallel because thermally grown oxide process causes Ga-N dissociation. In this study, NH3 pre-plasma treatment was carried out to improve the electrical properties of Atomic Layer Deposition (ALD) HfO2 GaN metal oxide semiconductor (MOS) devices. Processing parameters of plasma power, flow rate, process temperature and pressure for treatment were used with 50 watt, 100 sccm, 250 oC, 0.6 Torr, respectively. Process time was varied with 5, 10 and 15 minutes. Compared to device without passivation, a lower gate leakage current, a smaller frequency dispersion (2.2%), a negligible hysteresis (~10mV @1 KHz), and a reduced interface state density (6x1011 cm-2eV-1). These improved characteristics are attributed to the elimination of carbon-related species and the suppressed Ga-N dissociation by NH3 plasma treatment. In addition, hydrogen ion as a result of NH3 plasma improves interface state density. [Acknowledgement] This study was supported by the Industrial Technology Innovation Program (10054882, Development of dry cleaning technology for nanoscale patterns) funded by the Ministry of Trade, Industry and Energy (MOTIE, Republic of Korea) |
| 저자 | 정우석, 임동환, 김영진, 한훈희, 손석기, Andrey Sokolov Sergeevich, 이재호, 최창환 |
| 소속 | 한양대 |
| 키워드 | GaN; NH<SUB>3</SUB> Plasma Passivation; Interface State Density |
