Kilovolt-class β-Ga2O3 MOSFETs on 1-in. bulk substrates

Abstract

We report on the demonstration of β-Ga2O3 MOSFETs fabricated on 1-in. bulk substrates using metalorganic vapor phase epitaxy (MOVPE) with disilane (Si2H6) as the silicon precursor. Sheet charge uniformity of the as-grown films was measured via Hall and ranged from 5.9–6.7 × 1012 cm−2 with a uniform Hall mobility of 125–129 cm2/V s across the sample. MOSFET devices with a source-drain length of 5.1 μm were measured across the wafer and had a minimum on-resistance (RON) of 47.87 Ω mm with a maximum on-current (ION) of 165 mA/mm. For these same devices, the on-current (ION) and pinch-off voltage (VP) uniformity across the wafer were 137 ± 12 mA/mm and −27.3 ± 7.3 V, respectively. Devices showed low reverse leakage current until catastrophic breakdown occurred, with measured breakdown voltages (VBR) of up to 2.15 kV. This work provides valuable insights into understanding the growth, fabrication, and characterization processes for β-Ga2O3 FETs on full wafer-scale substrates. It also projects the promise of developing lateral β-Ga2O3 FETs with high current-carrying capabilities and breakdown voltages, especially on substrates of 1 in. or larger.