Study of the Bonding Characteristics at β-Ga2O3(201)/4H-SiC(0001) Interfaces from First Principles and Experiment

Abstract

For the first time, β-Ga2O3 were prepared on 4H-SiC (0001) substrates using a low-pressure chemical vapor deposition (LPCVD) technique. The obtained β-Ga2O3/4H-SiC heterostructures display strongly preferential growth orientation along the <201> of β-Ga2O3. Combining the experimental results, interfacial properties, such as the work of adhesion (Wad), electronic properties and bonding characteristics of β-Ga2O3(201)/4H-SiC(0001) heterointerface were systemically studied using first principles. Four different β-Ga2O3(201)/4H-SiC(0001) interface models composed of different atom stacking sequences were established. It was found that the interface consisting of silicon terminated of 4H-SiC (0001), and oxygen terminated of β-Ga2O3(201) (Si-O) has the lowest relaxation energy and the highest stability. Results indicated that the binding of interface Si and C to the O atoms is stronger than that to the Ga atoms. The results of the difference charge density and electron localization function reveals that the Si and C atoms at interface are bonded with O atoms of β-Ga2O3 by covalent bonds, in which Si-O and C-O covalent bonds play a favorable role in the final stable configurations formation. This work will provide a further understanding of the various electronic behaviors of the β-Ga2O3(201)/4H-SiC(0001) heterointerface.