Yeom Min Jae, Yang Jeong Yong, Lee Chan Ho, Heo Junseok, Chung Roy Byung Kyu, Yoo Geonwook
School of Electronic Engineering, Soongsil University, Seoul 06938, Korea.
Department of Electrical and Computer Engineering, Ajou University, Suwon 16499, Korea.
Micromachines (Basel). 2021 Nov 25;12(12):1441. doi: 10.3390/mi12121441.
AlGaN/GaN metal-oxide semiconductor high electron mobility transistors (MOS-HEMTs) with undoped ferroelectric HfO have been investigated. Annealing is often a critical step for improving the quality of as-deposited amorphous gate oxides. Thermal treatment of HfO gate dielectric, however, is known to degrade the oxide/nitride interface due to the formation of Ga-containing oxide. In this work, the undoped HfO gate dielectric was spike-annealed at 600 °C after the film was deposited by atomic layer deposition to improve the ferroelectricity without degrading the interface. As a result, the subthreshold slope of AlGaN/GaN MOS-HEMTs close to 60 mV/dec and on/off ratio>10 were achieved. These results suggest optimizing the HfO/nitride interface can be a critical step towards a low-loss high-power switching device.
对具有未掺杂铁电HfO的AlGaN/GaN金属氧化物半导体高电子迁移率晶体管（MOS-HEMT）进行了研究。退火通常是提高沉积态非晶栅氧化物质量的关键步骤。然而，已知HfO栅介质的热处理会由于含Ga氧化物的形成而使氧化物/氮化物界面退化。在这项工作中，通过原子层沉积法沉积薄膜后，对未掺杂的HfO栅介质在600℃进行尖峰退火，以提高铁电性而不使界面退化。结果，实现了AlGaN/GaN MOS-HEMT的亚阈值斜率接近60 mV/dec且开/关比>10。这些结果表明，优化HfO/氮化物界面可能是迈向低损耗高功率开关器件的关键一步。
