2 - MBE growth and characterization of gallium oxide

Abstract

Ultrawide bandgap (UWBG) semiconductors can have higher figure of merit values than existing materials for power and radio frequency (rf) devices and are increasingly viewed as the next-generation semiconductors in high-power/temperature electronics. Gallium oxide (Ga2O3) is one of the UWBG semiconductors and has five different known polymorphs. Recently, there has been great interest in the most stable (β-Ga2O3) and metastable (ɛ- and α-Ga2O3) polymorphs of Ga2O3. In this chapter, we discuss molecular beam epitaxy (MBE) growth and characterization of β- and ɛ-Ga2O3. After a brief introduction, the chapter discusses MBE equipment considerations, amorphous Ga2O3 for gate dielectrics, heteroepitaxial growth of Ga2O3, and then focuses on homoepitaxial growth and metastable phase stabilization by MBE in Section 2.2. Section 2.3 discusses current and future prospects, and finally a summary is presented in Section 2.4.