Sun Mengyuan, Wang Luyu, Zhang Penghao, Chen Kun
State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, China.
Shanghai Integrated Circuit Manufacturing Innovation Center Co., Ltd., Shanghai 200433, China.
Micromachines (Basel). 2023 May 23;14(6):1100. doi: 10.3390/mi14061100.
A novel monocrystalline AlN interfacial layer formation method is proposed to improve the device performance of the fully recessed-gate AlO/AlN/GaN Metal-Insulator-Semiconductor High Electron Mobility Transistors (MIS-HEMTs), which is achieved by plasma-enhanced atomic layer deposition (PEALD) and in situ N plasma annealing (NPA). Compared with the traditional RTA method, the NPA process not only avoids the device damage caused by high temperatures but also obtains a high-quality AlN monocrystalline film that avoids natural oxidation by in situ growth. As a contrast with the conventional PELAD amorphous AlN, results indicated a significantly lower interface density of states () in a MIS characterization, which could be attributed to the polarization effect induced by the AlN crystal from the X-ray Diffraction (XRD) and Transmission Electron Microscope (TEM) characterizations. The proposed method could reduce the subthreshold swing, and the AlO/AlN/GaN MIS-HEMTs were significantly enhanced with ~38% lower on-resistance at = 10 V. What is more, in situ NPA provides a more stable threshold voltage () after a long gate stress time, and Δ is inhibited by about 40 mV under = 10 V for 1000 s, showing great potential for improving AlO/AlN/GaN MIS-HEMT gate reliability.
提出了一种新型的单晶AlN界面层形成方法，以提高全凹槽栅AlO/AlN/GaN金属-绝缘体-半导体高电子迁移率晶体管（MIS-HEMT）的器件性能，该方法通过等离子体增强原子层沉积（PEALD）和原位N等离子体退火（NPA）实现。与传统的快速热退火（RTA）方法相比，NPA工艺不仅避免了高温对器件造成的损伤，还通过原位生长获得了高质量的AlN单晶膜，避免了自然氧化。与传统的PELAD非晶AlN相比，MIS表征结果表明界面态密度（）显著降低，这可归因于X射线衍射（XRD）和透射电子显微镜（TEM）表征中AlN晶体引起的极化效应。所提出的方法可以降低亚阈值摆幅，并且在V = 10 V时，AlO/AlN/GaN MIS-HEMT的导通电阻显著降低约38%，性能得到显著提升。此外，原位NPA在长时间栅极应力后提供了更稳定的阈值电压（），在V = 10 V下施加1000 s时，Δ被抑制约40 mV，显示出在提高AlO/AlN/GaN MIS-HEMT栅极可靠性方面的巨大潜力。
