Band alignment of atomic layer deposited high-k Al2O3/multilayer MoS2 interface determined by X-ray photoelectron spectroscopy

Abstract High-resolution x -ray photoelectron spectroscopy (XPS) was employed to characterize the energy band alignment between TiO 2 /multilayer (ML)-MoS 2 . The TiO 2 film and ML-MoS 2 film was grown by an atomic layer deposition (ALD) and chemical vapor deposition (CVD), respectively. The effect of CHF 3 plasma treatment on the band alignment between TiO 2 /ML-MoS 2 was evaluated. It was found that the valence band offset (VBO) and a conduction band offset (CBO) of TiO 2 /ML-MoS 2 interface was changed from 2.28 eV to 2.51 eV, and from 0.28 eV to 0.51 eV, respectively for the sample with CHF 3 plasma treatment. With the CHF 3 plasma treatment, the down-shift of Mo 3d core level binding energy results in a bend-up of energy potential on the MoS 2 side, leading to 0.23 eV ΔE C difference between the control and the sample with CHF 3 plasma treatment, which is caused by the interfacial layer in rich of F element. The physics details of the band alignment at TiO 2 /ML-MoS 2 interface will provide a guide for the MoS 2 based electronic device design.