Breakdown and C-V Characteristics Analysis of Depletion Mode Lateral β-Ga2O3 MOSFET

Gallium oxide (Ga2O3) has recently become a highly intriguing semiconductor, particularly in the field of power electronics. Ultra-wide bandgap (~5 eV) and higher dielectric constant (~10.5-12.5) are the two properties far better than silicon carbide (SiC) and gallium nitride (GaN). $\beta-\text{Ga}_{2}\mathrm{O}_{3}$ is the most stable phase among the five polymorphs $(\alpha, \beta, \gamma, \delta$, and $\epsilon$). Moreover, a key advantage of $\beta-\text{Ga}_{2}\mathrm{O}_{3}$ over SiC and GaN is its ability to produce high-quality native crystals at a lower cost. Devices based on $\beta-\text{Ga}_{2}\mathrm{O}_{3}$, such as Schottky barrier diodes and depletion-mode lateral MOSFETs, have demonstrated stable I-V characteristics at voltages exceeding 1 kV. However, limited research has been conducted on the capacitance-voltage (C-V) analysis of $\beta-\text{Ga}_{2}\mathrm{O}_{3}$ devices. This paper presents a TCAD simulation of a $\beta-\text{Ga}_{2}\mathrm{O}_{3}$ depletion-mode lateral MOSFET (D-MOSFET), which exhibits stable characteristics up to 370V. The reverse transfer capacitance (Crss), output capacitance (Coss), and input capacitance (Ciss) of the device were analyzed using Silvaco. The lower capacitances are expected because of the higher dielectric constant of $\beta-\text{Ga}_{2}\mathrm{O}_{3}$. Additionally, the electron concentration distribution was studied to illustrate the expansion of the depletion region with increasing drain voltage. These findings provide valuable insights for future modeling and optimization of $\beta-\text{Ga}_{2}\mathrm{O}_{3}$ depletion-mode lateral MOSFETs.