Molecular Beam Epitaxy of Ga2O3

Abstract

Molecular beam epitaxy (MBE) has allowed for growth of the highest quality films of β-Ga2O3 and its alloys. In this chapter, we discuss the fundamentals of both plasma-assisted and ozone MBE of β-Ga2O3. The impact of Ga2O suboxide desorption during growth is reviewed along with its implications for growth on various crystallographic orientations of β-Ga2O3, with the (010) orientation showing the most promise for conventional MBE growth. Indium catalyzed growth in MBE is compared with conventional MBE growth, with the catalytic growth showing the ability to expand the growth window, improve maximum growth rates, and allow for higher quality films across different orientations of β-Ga2O3. The doping characteristics and capabilities for a variety of dopants in MBE grown β-Ga2O3 films are analyzed. Hall measurements reveal information about the electronic quality of MBE grown β-Ga2O3 as well as the electronic nature of the dopants themselves. Growth and characterization of β-(AlxGa1-x)2O3 and β-(InxGa1-x)2O3 are discussed for future heterostructure based devices. Progress on MBE growth of β-Ga2O3 shows much promise for its application to electron devices, but there is still much to explore in the field.