Enhanced interface properties of diamond MOSFETs with Al2O3 gate dielectric deposited via ALD at a high temperature

• 作者: Yu Fu Rui-Min Xu Xin-Xin Yu Jian-Jun Zhou Yue-Chan Kong Tang-Sheng Chen Bo Yan Yan-Rong Li Zheng-Qiang Ma Yue-Hang Xu
• 来源期刊: 中国物理B（英文版）
• 年，卷（期）: 2021,（5）
• 所属期刊栏目: INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY
• 页码范围: 746-752
• 页数: 7页
• 语种: 英文
• DOI: 10.1088/1674-1056/abd749

摘要

The interface state of hydrogen-terminated (C-H) diamond metal-oxide-semiconductor field-effect transistor (MOS-FET) is critical for device performance.In this paper,we investigate the fixed charges and interface trap states in C-H diamond MOSFETs by using different gate dielectric processes.The devices use Al2O3 as gate dielectrics that are de-posited via atomic layer deposition (ALD) at 80 ℃ and 300 ℃,respectively,and their C-V and Ⅰ-Ⅴ characteristics are comparatively investigated.Mott-Schottky plots (1/C2-VG) suggest that positive and negative fixed charges with low den-sity of about 1011 cm-2 are located in the 80-℃-and 300-℃ deposition Al2O3 films,respectively.The analyses of direct current (DC)/pulsed Ⅰ-Ⅴ and frequency-dependent conductance show that the shallow interface traps (0.46 eV-0.52 eV and 0.53 eV-0.56 eV above the valence band of diamond for the 80-℃ and 300-℃ deposition conditions,respectively) with distinct density (7.8 × 1013 eV-1·cm-2-8.5 × 1013 eV-1·cm-2 and 2.2 × 1013 eV-1·cm-2-5.1 × 1013 eV-1·cm-2 for the 80-℃-and 300-℃-deposition conditions,respectively) are present at the Al2O3/C-H diamond interface.Dynamic pulsedⅠ-Ⅴ and capacitance dispersion results indicate that the ALD Al2O3 technique with 300-℃ deposition temperature has higher stability for C-H diamond MOSFETs.