We have fabricated lateral β-Ga2O3 MOSFETs on a 2″ (010) substrate with peripheries ranging from 100 μm to 2 mm and an overall yield of 84.5% (over 95% excluding edge dies). Devices featured source–drain spacings of 1, 2, and 5 μm with regrown ohmic contacts and scaled T-gates. 1 μm devices had Ron as low as 24 Ω · mm and 5 μm devices showed Vbk as high as 863 V. Average fT and fmax for 1, 2 and 5 μm devices were 7 ± 2, 6 ± 1, and 3.7 ± 0.7 and 22 ± 4, 17 ± 3, and 9 ± 0.9 GHz, respectively. Under large-signal operation, a 2 mm-periphery, 2 μm device demonstrated a Pout value of 467 mW (26.7 dB) at 5 GHz, the highest reported net RF power for a Ga2O3 transistor. Aggregate device performance was analyzed and sources of device failure and performance degradation were identified, including short-channel effects and gate leakage. These results demonstrate the viability of β-Ga2O3 MOSFET fabrication on large-area substrates and provide insight into technical barriers in manufacturability.
Dryden et al. (Mon,) studied this question.