【Device Papers】β-Ga₂O₃/p-Si (100) based vertical diode deposited using RF sputtering for rectifier design

      Researchers from the NIT Meghalaya have published a dissertation titled "β-Ga₂O₃/p-Si (100) based vertical diode deposited using RF sputtering for rectifier design" in Micro and Nanostructures.

Abstract

      Conventional Si-based devices are limited in high-power and high-frequency applications due to their narrow bandgap and poor thermal stability. To address these limitations, β-Ga₂O₃/p-Si heterojunction diodes were fabricated using RF sputtering for next-generation devices. Structural, optical, and chemical state analyses of the deposited Ga₂O₃ films confirm the formation of the β-phase with a polycrystalline nature, where the (403) plane emerges as the dominant crystallographic orientation. The crystallite size was estimated to be ~15.05 nm from XRD, while cross-sectional FESEM confirmed a uniform film thickness of ~120 nm. The fabricated Ga₂O₃/p-Si diode exhibits excellent rectifying performance, with a high breakdown voltage (V_BR) of 223 V, a low on-resistance (R_on) of 21 mΩ cm², an ideality factor of 3.5, a built-in potential (V_bi) of 0.52 V, and a carrier concentration of . The device demonstrates a rectification ratio of 6.23 × 10¹⁵cm^-3 at 4 V and a reverse saturation current density (J₀) of 3.804 × 10^-5 A/cm². TCAD simulation results were calibrated against experimental data, and SPICE parameters were extracted using the SILVACO UTMOST IV-compatible model. The Verilog-A implementation in Cadence validated the diode behavior in an AC–DC rectifier circuit. The rectifier exhibited stable and efficient operation up to the MHz range, while higher frequencies led to noticeable leakage degradation. These results highlight the potential of RF-sputtered Ga₂O₃/Si heterojunctions for high-power and high-frequency electronic device applications.

DOI：

https://doi.org/10.1016/j.micrna.2025.208495