High performance E-mode NiO/β-Ga2O3 HJ-FET with high conduction band offset and thin recessed channel

In this paper, an enhancement-mode (E-mode) NiO/β-Ga₂O₃ heterojunction field-effect transistor (HJ-FET) with high conduction band offset (ΔE_C) and thin recessed channel is proposed and studied by Sentaurus TCAD. Different from the existing HJ-FET with low ΔE_C alignment, the High ΔE_C HJ-FET can achieve a much lower on-resistance (R_on) due to the strong electron confinement effect. More importantly, the disadvantage in the threshold voltage (V_th) is compensated by reducing the thickness of the recessed channel, maintaining an almost unchanged R_on with the help of the special surface conduction channel. Compared with the corresponding Low ΔE_C HJ-FET, at the same V_th ($\sim$ 0.82 V), the R_on is decreased from 135 Ω/mm to 90.7 Ω/mm and the maximum drain current is increased from 14.9 mA/mm to 83.1 mA/mm. By adding a top p-NiO layer for further optimization, a greatly improved power figure of merit (P-FOM) of 2.29 GW/cm² is achieved among the E-mode HJ-FETs. These results show that the proposed High ΔE_C HJ-FET with thin recessed channel is probably a better choice to achieve the high-performance E-mode lateral HJ-FET.