Spectroscopic Calculation of Band Alignment Between High Permittivity Composites ZrSiO, AlSiO and β-Ga2O3

Monoclinic gallium oxide ( β -Ga 2 O 3 ) combined with high permittivity composites (such as HfZrO, HfAlO, et al.) has exhibited great potential for promote performance and stability of power transistors. In this study, the ZrSiO/ β -Ga 2 O 3 , AlSiO/ β -Ga 2 O 3 heterojunctions are fabricated by low-pressure chemical vapor deposition (LPCVD) and radio frequency magnetron sputtering. The interfacial chemical properties, crystalline structures, surface morphologies, and band alignments of ZrSiO/ β -Ga 2 O 3 , AlSiO/ β -Ga 2 O 3 have been analyzed by various measurements. Both ZrSiO, AlSiO, and β -Ga 2 O 3 films own great crystal quality, and a smooth surface with low roughness. Based in the X-ray photoelectron spectroscopy (XPS), the valence band offset (Δ E v ) of ZrSiO/ β -Ga 2 O 3 , AlSiO/ β -Ga 2 O 3 is estimated to be 0.41 ± 0.03, 0.76 ± 0.02 eV, respectively, using the Ga 2p , Al 2p , Si 2p and Zr 3d core levels as references. It is found that both ZrSiO/ β -Ga 2 O 3 , and AlSiO/ β -Ga 2 O 3 heterojunction show a straddling type I alignment with large conduction band offset (Δ E c ) of 1.74 ± 0.03, 2.30 ± 0.02 eV, respectively. These results demonstrate that feasibility of ZrSiO/ β -Ga 2 O 3 , AlSiO/ β -Ga 2 O 3 heterojunctions with a type I band alignment, sufficient band offsets, smooth surface, and decent film quality, which could be one of the promising candidates for developing high performance β -Ga 2 O 3 devices and power applications.