Interfacial chemistry and energy band alignment of TiAlO on 4H-SiC determined by X-ray photoelectron spectroscopy

• DOI: 10.1016/j.apsusc.2017.02.257
• Publication Date: 2017-03-05T01:01:58Z
• Authors: Qian Wang; Xinhong Cheng; Li Zheng; Peiyi Ye; Menglu Li; Lingyan Shen; Jingjie Li; Dongliang Zhang; Ziyue Gu; Yuehui Yu
• Keywords: High-κ dielectric

Abstract Intermixing of TiO 2 with Al 2 O 3 to form TiAlO films on 4H-SiC is expected to simultaneously boost the dielectric constant and achieve sufficient conduction/valence band offsets (CBO/VBO) between dielectrics and 4H-SiC. In this work, a composite TiAlO film rather than TiO 2 -Al 2 O 3 laminations is deposited on 4H-SiC by plasma enhanced atomic layer deposition (PEALD). X-ray photoelectron spectroscopy (XPS) is performed to systematically analyze the interfacial chemistry and energy band alignment between TiAlO and 4H-SiC. An interfacial layer composed of Ti, Si, O and C forms between TiAlO and 4H-SiC during PEALD process. The VBO and CBO between TiAlO and 4H-SiC are determined to be 1.45 eV and 1.10 eV, respectively, which offer competitive barrier heights (>1 eV) for both electrons and holes and make it suitable for the fabrication of 4H-SiC metal-oxide-semiconductor field effect transistors (MOSFETs).