A Sn-doped (100) $\beta $ -Ga2O3 epitaxial layer was grown via metal–organic vapor phase epitaxy onto a single-crystal, Mg-doped semi-insulating (100) $\beta $ -Ga2O3 substrate. Ga2O3-based metal–oxide–semiconductor field-effect transistors with a 2- $\mu \text{m}$ gate length ( $L_{G})$ , 3.4- $\mu \text{m}$ source–drain spacing ( $L_{\textrm {SD}})$ , and 0.6- $\mu \text{m}$ gate–drain spacing ( $L_{\textrm {GD}})$ were fabricated and characterized. Devices were observed to hold a gate-to-drain voltage of 230 V in the OFF-state. The gate-to-drain electric field corresponds to 3.8 MV/cm, which is the highest reported for any transistor and surpassing bulk GaN and SiC theoretical limits. Further performance projections are made based on layout, process, and material optimizations to be considered in future iterations.

3.8-MV/cm Breakdown Strength of MOVPE-Grown Sn-Doped $\beta $ -Ga 2 O 3 MOSFETs

This letter demonstrates GaN vertical Schottky and p-n diodes on Si substrates for the first time. With a total GaN drift layer of only 1.5- $\mu{\rm m}$ thick, a breakdown voltage (BV) of 205 V was achieved for GaN-on-Si Schottky diodes, and a soft BV higher than 300 V was achieved for GaN-on-Si p-n diodes with a peak electric field of 2.9 MV/cm in GaN. A trap-assisted space-charge-limited conduction mechanism determined the reverse leakage and breakdown mechanism for GaN-on-Si vertical p-n diodes. The on-resistance was 6 and 10 ${\rm m}\Omega\cdot{\rm cm}^{2}$ for the vertical Schottky and p-n diode, respectively. These results show the promising performance of GaN-on-Si vertical devices for future power applications.

GaN-on-Si Vertical Schottky and p-n Diodes

In this letter, we present AlGaN/GaN lateral Schottky barrier diodes on silicon with recessed anodes and dual field plates. A low specific ON-resistance $R_{{\rm ON, SP}}$ (5.12 $\text{m}\Omega \cdot \textrm {cm}^{2}$ ), a low turn-ON voltage ( 1.9 kV) were simultaneously achieved in devices with a 25- $\mu \text{m}$ anode/cathode distance, resulting in a power figure-of-merit BV $^{2}$ / $R_{{\rm ON, SP}}$ of 727 $\textrm {MW}\,\cdot \, \textrm {cm}^{-2}$ . The record high BV of 1.9 kV is attributed to the dual field-plate structure.

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1.9-kV AlGaN/GaN Lateral Schottky Barrier Diodes on Silicon

Vertical geometry Ni/Au-β-Ga2O3 Schottky rectifiers were fabricated on Hydride Vapor Phase Epitaxy layers on conducting bulk substrates, and the rectifying forward and reverse current-voltage characteristics were measured at temperatures in the range of 25–100 °C. The reverse breakdown voltage (VBR) of these β-Ga2O3 rectifiers without edge termination was a function of the diode diameter, being in the range of 920–1016 V (average value from 25 diodes was 975 ± 40 V, with 10 of the diodes over 1 kV) for diameters of 105 μm and consistently 810 V (810 ± 3 V for 22 diodes) for a diameter of 210 μm. The Schottky barrier height decreased from 1.1 at 25 °C to 0.94 at 100 °C, while the ideality factor increased from 1.08 to 1.28 over the same range. The figure-of-merit (VBR2/Ron), where Ron is the on-state resistance (∼6.7 mΩ cm2), was approximately 154.07 MW·cm−2 for the 105 μm diameter diodes. The reverse recovery time was 26 ns for switching from +5 V to −5 V. These results represent another impressive advanc...

High reverse breakdown voltage Schottky rectifiers without edge termination on Ga2O3

High-performance AlGaN/GaN diodes are realized on 8-in Si wafers with Au-free CMOS-compatible technology. The diodes are cointegrated on the same substrate together with the AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors and with only one extra lithographic step. The diode anode and the transistor gate are processed together and the same metallization is used for both, avoiding extra metal deposition dedicated to the Schottky junction. A gated edge termination allows obtaining low reverse leakage current (within 1 μA/mm at -600 V), which is several orders of magnitude lower than the one of conventional Schottky diodes processed on the same wafer. Recess is implemented at the anode, resulting in low diode turn-on voltage values.

Au-Free AlGaN/GaN Power Diode on 8-in Si Substrate With Gated Edge Termination

GaN-based heterostructure lateral Schottky barrier diodes (SBDs) grown on n-SiC substrate are investigated in this letter. These SBDs own very low onset voltage VF = 0.43 V, high reverse blocking VBR >; 1000 V, very low capacitive charge of 0.213 nC/A, and a very fast recovery time of 10 ps. These unique qualities are achieved by combining lateral topology, GaN:C back-barrier epitaxial structure, fully recessed Schottky anode (φB = 0.43 eV), and slanted anode field plate in a robust and innovative process. Diode operation at elevated temperature up to 200 °C was also characterized.

A. Wentzel

Papers

Fast-Switching GaN-Based Lateral Power Schottky Barrier Diodes With Low Onset Voltage and Strong Reverse Blocking