We report on metalorganic chemical vapor deposition (MOCVD) growth of controllably Si-doped 4.5 μm thick β-Ga2O3 films with electron concentrations in the 1015 cm−3 range and record-high room temperature Hall electron mobilities of up to 200 cm2/V.s, reaching the predicted theoretical maximum room temperature mobility value for β-Ga2O3. Growth of the homoepitaxial films was performed on Fe-doped (010) β-Ga2O3 substrates at a growth rate of 1.9 μm/hr using TEGa as the Gallium precursor. To probe the background electron concentration, an unintentionally doped film was grown with a Hall concentration of 3.43 x 1015 cm−3 and Hall mobility of 196 cm2/V.s. Growth of intentionally Si-Doped films was accomplished by fixing all growth conditions and varying only the silane flow, with controllable Hall electron concentrations ranging from 4.38 x 1015 cm−3 to 8.30 x 1015 cm−3 and exceptional Hall mobilities ranging from 194 - 200 cm2/V.s demonstrated. C-V measurements showed a flat charge profile with the ND+ - NA− values correlating well with the Hall-measured electron concentration in the films. SIMS measurements showed the silicon atomic concentration matched the Hall electron concentration with Carbon and Hydrogen below detection limit in the films. The Hall, C-V, and SIMS data indicate the growth of high-quality 4.5 μm thick β-Ga2O3 films and controllable doping into the mid 1015 cm−3 range. These results demonstrate MOCVD growth of electronics grade record-high mobility, low carrier density, and thick β-Ga2O3 drift layers for next generation vertical β-Ga2O3 power devices.
@article{arxiv.2407.17089,
title = {Record-High Electron Mobility and Controlled Low 10$^{15}$ cm$^{-3}$ Si-doping in (010) $\beta$-Ga$_2$O$_3$ Epitaxial Drift Layers},
author = {Carl Peterson and Arkka Bhattacharyya and Kittamet Chanchaiworawit and Rachel Kahler and Saurav Roy and Yizheng Liu and Steve Rebollo and Anna Kallistova and Thomas E. Mates and Sriram Krishnamoorthy},
journal= {arXiv preprint arXiv:2407.17089},
year = {2024}
}