Application of halide vapor phase epitaxy for the growth of ultra-wide band gap Ga₂O₃

Abstract

Halide vapor phase epitaxy (HVPE) is widely used in the semiconductor industry for the growth of Si, GaAs, GaN, etc. HVPE is a non-organic chemical vapor deposition (CVD) technique, characterized by high quality growth of epitaxial layers with fast growth rate, which is versatile for the fabrication of both substrates and devices with wide applications. In this paper, we review the usage of HVPE for the growth and device applications of Ga2O3, with detailed discussions on a variety of technological aspects of HVPE. It is concluded that HVPE is a promising candidate for the epitaxy of large-area Ga2O3 substrates and for the fabrication of high power β-Ga2O3 devices.

Projected Cost of Gallium Oxide Wafers from Edge-Defined Film-Fed Crystal Growth

“…For the heteroepitaxial growth step in the fabrication of Ga 2 O 3 wafers, growth rates of over 250 μm/h have previously been achieved using halide vapor phase epitaxy (HVPE), which is a chemical vapor deposition (CVD) technique in which one of the precursors is a halide. However, growing films at that rapid rate results in a rough surface of the film.…”

“…However, growing films at that rapid rate results in a rough surface of the film. HVPE typically consists of a reaction between the metal precursor (Ga in this case) and a halide to form a more chemically reactive metal halide (commonly Ga + HCl → GaCl + H 2 or a similar reaction starting from Cl 2 ), which is then reacted with the anion of choice in a different temperature zone (most commonly GaCl + O 2 → Ga 2 O 3 + Cl 2 , but sometimes using H 2 O as the oxygen precursor). − Theoretical and experimental results indicate that Ga 2 O 3 growth via HVPE is thermodynamically controlled and that the GaCl partial pressure plays a significant role in the growth rate. In a thermodynamic study of HVPE growth rates for Ga 2 O 3 , a growth rate of 20 μm/h was found to be both reasonable and achievable, so 20 μm/h was set as the epitaxial growth rate in the model.…”

Ga2O3 and Related Ultra-Wide Bandgap Power Semiconductor Oxides: New Energy Electronics Solutions for CO2 Emission Mitigation

“…Furthermore, with the presence of chlorine catalyst in the growth chamber, this technique exhibits the growth of metastable phases of Ga 2 O 3 , such as α and ε [ 57 ]. The HVPE method suffers from a high level of roughness on the surface even at a relatively low growth rate [ 56 , 58 ]; an electrical mechanical [ 59 ] or a chemical mechanical [ 60 ] polishing can be employed to remove further deep surface pits formed during the growth. Leach et al [ 61 ] reported a vast difference in surface morphology and XRD full-width half-maximum (FWMH), between sufficiently and insufficiently CMP polished (discriminated by the polishing times of the various polishing steps) β -Ga 2 O 3 wafers grown by HVPE.…”

Deep-ultraviolet integrated photonic and optoelectronic devices: A prospect of the hybridization of group III–nitrides, III–oxides, and two-dimensional materials

“…The thicknesses of the QWs and QBs also affect hole concentration. Fewer than a couple nanometers of QW thickness and less than 8 nm for QB are the thicknesses recommended for the high hole concentrations and excellent spatial overlap of the electron-hole wavefunctions [718][719][720][721] .…”