Record-High Electron Mobility and Controlled Low 10${}^{15}$ cm${}^{-3}$ Si-doping in (010) $\beta$-Ga${}_2$O${}_3$ Epitaxial Drift Layers

Abstract

We report on metalorganic chemical vapor deposition (MOCVD) growth of controllably Si-doped 4.5 $\mu$m thick $\beta$-Ga${}_2$O${}_3$ films with electron concentrations in the 10${}^{15}$ cm${}^{-3}$ range and record-high room temperature Hall electron mobilities of up to 200 cm${}^2$/V.s, reaching the predicted theoretical maximum room temperature mobility value for $\beta$-Ga${}_2$O${}_3$. Growth of the homoepitaxial films was performed on Fe-doped (010) $\beta$-Ga${}_2$O${}_3$ substrates at a growth rate of 1.9 $\mu$m/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 10${}^{15}$ cm${}^{-3}$ and Hall mobility of 196 cm${}^2$/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 10${}^{15}$ cm${}^{-3}$ to 8.30 x 10${}^{15}$ cm${}^{-3}$ and exceptional Hall mobilities ranging from 194 - 200 cm${}^2$/V.s demonstrated. C-V measurements showed a flat charge profile with the N${}_D^{+}$ - N${}_A^{-}$ 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 $\mu$m thick $\beta$-Ga${}_2$O${}_3$ films and controllable doping into the mid 10${}^{15}$ cm${}^{-3}$ range. These results demonstrate MOCVD growth of electronics grade record-high mobility, low carrier density, and thick $\beta$-Ga${}_2$O${}_3$ drift layers for next generation vertical $\beta$-Ga${}_2$O${}_3$ power devices.

16 Pages, 10 Figures, 2 Tables

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Cited by in corpus (3)

• LPCVD Grown Si-Doped $\beta$-Ga${}_2$O${}_3$ Films with Promising Electron Mobilities
• LPCVD based Plasma Damage Free in situ etching of $\beta$-Ga${}_2$O${}_3$ using Solid Source Gallium
• Quasi-Vertical $\beta$-Ga${}_2$O${}_3$ Schottky Diodes on Sapphire Using All-LPCVD Growth and Plasma-Free Ga-Assisted Etching