β-Ga2O3 MESFETs with insulating Mg-doped buffer grown by plasma-assisted molecular beam epitaxy

In this work, we develop in situ Mg doping techniques in plasma-assisted molecular beam epitaxy (PAMBE) of beta-Ga2O3 to compensate Si dopants at the substrate epilayer growth interface and eliminate parasitic leakage paths. Both abrupt and uniform Mg doping profiles over a wide range of concentrations were achieved in beta-Ga2O3 epilayers grown by PAMBE. Capacitance-voltage characteristics of Si and Mg co-doped samples confirmed the compensating effect of the Mg dopants. Mg delta-doping was then integrated into a beta-Ga2O3 metal-semiconductor field effect transistor structure and shown to be effective in eliminating source leakage. The results presented here show that Mg doping is a promising way to engineer insulating buffer layers for beta-Ga2O3 lateral devices grown by PAMBE.

Automated summary

In this study, we have developed an in situ Mg doping technique in plasma-assisted molecular beam epitaxy for compensating Si dopants and eliminating parasitic leakage paths in beta-Ga2O3. The technique achieved both abrupt and uniform Mg doping profiles over a wide range of concentrations. Capacitance-voltage characteristics confirmed the compensating effect of Mg dopants. Mg delta-doping was also shown to effectively eliminate source leakage in beta-Ga2O3 metal-semiconductor field effect transistor structure.