title: Silicon diffusion control in atomic-layer-deposited Al2O3/La2O3/Al2O3 gate stacks using an Al2O3 barrier layer.
abstract: In this study, the physical and electrical characteristics of Al2O3/La2O3/Al2O3/Si stack structures affected by the thickness of an Al2O3 barrier layer between Si substrate and La2O3 layer are investigated after a rapid thermal annealing (RTA) treatment. Time of flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS) tests indicate that an Al2O3 barrier layer (15 atomic layer deposition (ALD) cycles, approximately 1.5 nm) plays an important role in suppressing the diffusion of silicon atoms from Si substrate into the La2O3 layer during the annealing process. As a result, some properties of La2O3 dielectric degenerated by the diffusion of Si atoms are improved. Electrical measurements (C-V, J-V) show that the thickness of Al2O3 barrier layer can affect the shift of flat band voltage (V FB) and the magnitude of gate leakage current density.
authors.affiliation: Key Laboratory for Wide-Band Gap Semiconductor Materials and Devices of Education, School of Microelectronics, Xidian University, No. 2, South Taibai Road, Yanta Zone, Xi'an City, Shaanxi Province 710071 People's Republic of China.
authors.forename: Xing
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory for Wide-Band Gap Semiconductor Materials and Devices of Education, School of Microelectronics, Xidian University, No. 2, South Taibai Road, Yanta Zone, Xi'an City, Shaanxi Province 710071 People's Republic of China.
authors.forename: Hong-Xia
authors.initials: HX
authors.lastname: Liu
authors.affiliation: Key Laboratory for Wide-Band Gap Semiconductor Materials and Devices of Education, School of Microelectronics, Xidian University, No. 2, South Taibai Road, Yanta Zone, Xi'an City, Shaanxi Province 710071 People's Republic of China.
authors.forename: Chen-Xi
authors.initials: CX
authors.lastname: Fei
authors.affiliation: Key Laboratory for Wide-Band Gap Semiconductor Materials and Devices of Education, School of Microelectronics, Xidian University, No. 2, South Taibai Road, Yanta Zone, Xi'an City, Shaanxi Province 710071 People's Republic of China.
authors.forename: Shu-Ying
authors.initials: SY
authors.lastname: Yin
authors.affiliation: Key Laboratory for Wide-Band Gap Semiconductor Materials and Devices of Education, School of Microelectronics, Xidian University, No. 2, South Taibai Road, Yanta Zone, Xi'an City, Shaanxi Province 710071 People's Republic of China.
authors.forename: Xiao-Jiao
authors.initials: XJ
authors.lastname: Fan
keywords: Atomic layer deposition; Diffusion; Equivalent oxide thickness; Interfacial layer; Silicate