Stress-induced charge trapping and electrical properties of atomic-layer-deposited HfAlO/Ga2O3 metal–oxide–semiconductor capacitors. (19th March 2019)

• Record Type: Journal Article
• Authors: Zhang, Hongpeng; Yuan, Lei; Jia, Renxu; Tang, Xiaoyan; Hu, Jichao; Zhang, Yimen; Zhang, Yuming; Sun, Jianwu
• Is Part Of: Journal of physics. Volume 52:Number 21(2019)
• Publication Date: 2019-03-19
• Subjects: gallium oxide -- HfAlO/Ga2O3 MOSCAP -- constant-voltage stress -- oxide traps; Physics -- Periodicals; 530
• DOI: 10.1088/1361-6463/ab0b93
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: Electrical properties and trapping characteristics of an atomic layer deposited Al-rich HfAlO/ β -Ga2 O3 capacitor were evaluated via constant-voltage stress (CVS), capacitance–voltage ( C – V ), and current–voltage ( I – V ) measurements. The magnitude of the stress-induced charge trapping increases with increasing voltage and time. The effective charges ( N eff ) including the 'border' traps located in near-interface oxide, interface traps ( D it ) of HfAlO/ β -Ga2 O3 interface, and fixed charges contribute significantly to the observed charge trapping, and it is found that interface traps contribute more under a large stress bias, compared with 'border' traps. In addition, the effective charge density is increased with stress time, implying that the contribution of negative sheet charges during the CVS process might not be negligible. Measurements of oxide permittivity (10.74), interface state density ( D it ~ 1 × 10 12 eV −1 cm −2 ), and gate leakage current (1.18 × 10 −5 A cm −2 at +10 V) have been extracted, suggesting the great electrical properties of Al-rich HfAlO/ β -Ga2 O3 MOSCAP. According to the above analysis, Al-rich HfAlO is an attractive candidate for normally off Ga2 O3 transistors.