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

• The band alignment of ALD-Al2O3/ML-MoS2 was characterized using XPS.
• The ΔEV and ΔEC of ALD-Al2O3/ML-MoS2 is found to be 4.10 eV and 3.41 eV, respectively.
• ALD-Al2O3 served as the gate dielectric for n-type ML-MoS2 based FETs has advantage of ALD-SiO2.

The energy band alignment between Al2O3/multilayer (ML)-MoS2 was characterized using high-resolution x-ray photoelectron spectroscopy (XPS). The Al2O3 was deposited using an atomic layer deposition (ALD) tool. A valence band offset of 4.10 eV and a conduction band offset of 3.41 eV were obtained across the ALD-Al2O3/ML-MoS2 interface. For comparison, the valence band offset and a conduction band offset were also obtained for ALD-SiO2/ML-MoS2 interface. It was found out that ALD-Al2O3/ML-MoS2 interface has a larger conduction band offset, compared to that of ALD-SiO2/ML-MoS2 interface, which indicate ALD-Al2O3 served as the gate dielectric for n-type ML-MoS2 based field effect transistors has advantage over ALD-SiO2 in term of suppressing the gate leakage current.