Homoepitaxial β-Ga2O3 transparent conducting oxide with conductivity σ = 2323 S cm−1

Abstract

Conductive homoepitaxial Si-doped β-Ga2O3 films were fabricated by pulsed laser deposition with an as-deposited 2323 S cm−1 conductivity (resistivity = 4.3 × 10−4 Ω-cm, carrier concentration = 2.24 × 1020 cm−3, mobility = 64.5 cm2 V−1 s−1, and electrical activation efficiency = 77%). High quality homoepitaxial films deposited on commercial (010) Fe-compensated β-Ga2O substrates were determined by high-resolution transmission electron microscopy and x-ray diffraction. The β-Ga2O3 films have ∼70% transparency from 3.7 eV (335 nm) to 0.56 eV (2214 nm). The combination of high conductivity and transparency offers promise for numerous ultrawide bandgap electronics and optoelectronic applications.

Recent progress on the effects of impurities and defects on the properties of Ga2O3

“…265,267,268 Based on this, homogeneous epitaxial doped b-Ga 2 O 3 films on Fe doped semi-insulating substrates have many advantages compared with heterogeneous epitaxial doped b-Ga 2 O 3 films, e.g., smooth surface (RMS o 0.5), high carrier concentrations (B10 20 cm À3 ) and electrical conductivity (m max = 2323 cm 2 V À1 s À1 ), low defects, good lattice match with the substrates, etc. 269 Therefore, homogeneous epitaxial thin films based on Fe doped semi-insulating substrates are widely applied in power devices. In addition, selecting the appropriate gate oxide dielectric material is crucial in the applications of FETs, because the lattice mismatch existing between the gate dielectric layer and the Ga 2 O 3 channel layer may further deteriorate the electronic performance of the interface.…”

Achieving n‐Type Conductivity in Epitaxial Ultrawide‐Bandgap β‐Ga2O3 Films via a Hf Doping Strategy

“…Instead, using extrinsic dopants including Si and Sn is more efficient to obtain highly conductive Ga 2 O 3 films. [8][9][10][11][12][13][14] To date, a majority of research efforts have been devoted to achieving large n-type conductivity of Ga 2 O 3 heteroepitaxial films. For example, Si-doped Ga 2 O 3 films can be deposited on foreign (MgAl 2 O 4 , sapphire) substrates by various methods such as pulsed laser deposition (PLD), [15,16] hydride vapor-phase epitaxy (HVPE), [17] and low-pressure chemical vapor deposition (LPCVD).…”

“…Instead, using extrinsic dopants including Si and Sn is more efficient to obtain highly conductive Ga 2 O 3 films. [ 8–14 ]…”

Large-Sized Nanocrystalline Ultrathin β-Ga2O3 Membranes Fabricated by Surface Charge Lithography

“…Ga 2 O 3 thin films prove to be a promising material for solar-blind photodetectors due to its large bandgap and UVC absorption [23], transparent electrodes for optical devices [24,25], gas sensors [26], and high-power Schottky barrier diodes with breakdown field exceeding 1 kV [27]. Moreover, Hwang et al [28] demonstrated the first high-voltage transistor based on β-Ga 2 O 3 nanomembranes exfoliated from bulk crystals.…”