MOCVD Growth of β-Ga2O3 Epitaxy

Abstract

This chapter discusses the MOCVD growth of epitaxial β-Ga2O3 films. MOCVD is the most suitable method for growing high-quality epitaxial β-Ga2O3 films with epitaxial maturity comparable to Silicon carbide (SiC) and Gallium nitride (GaN). Key metalorganic precursors, oxygen sources, dopant sources, and reactor geometries used for the MOCVD growth of Ga2O3 are discussed. Moreover, process conditions to manage Si accumulation at film and substrate interfaces, mitigate carbon and hydrogen incorporation into the films, and grow high purity films using trimethylgallium (TMGa) and triethylgallium (TEGa) precursors are presented. Transport properties of Si and Ge doped Ga2O3 films grown by MOCVD were analyzed to characterize the purity of the films, identify donor states, and determine donor and acceptor concentrations in the films. High purity epitaxial β-Ga2O3 films with record low temperature electron mobility exceeding 23,000 cm2/Vs and acceptor concentration of 2 × 1013 cm−3 were realized. This chapter provides insight into the MOCVD growth of high quality epitaxial Ga2O3 thin films and points out challenges that require future optimization to grow epitaxial layers suitable for various power device architectures.