600 V/7 A Large-Size RESURF β-Ga2O3 Schottky Barrier Diode With High-Temperature Storage Test

A new design concept to improve the blocking capability and reliability is proposed and verified by simulations and experiments. Based on the concept, the reduced surface field (RESURF)
$\beta $
-Ga2O3 Schottky barrier diode (SBD) is fabricated. Its electrical characteristics are investigated and the thermal stability is evaluated by the long-time high-temperature storage (HTS) test from 400 to 450 K. The RESURF structure is achieved by the oxidation region and SiO2 trench termination. First, the oxidation region is formed by thermal oxidation treatment (TOT) to reduce the surface electron concentration and passivate the oxygen-vacancy type interface states. It not only reduces surface electric field peak (
${E}_{\text {max}}{)}$
and optimizes the vertical electric field profile, but also improves reliability. Second, the SiO2 trench further reduces the charges to decrease the surface
${E} _{\text {max}}$
. The large-size RESURF SBD exhibits a withstand voltage of 600 V with the reverse leakage current (
${I}_{\text {R}}{)}$
of less than
$10 ~\mu \text{A}$
, as well as a forward current (
${I}_{\text {F}}{)}$
of 7 A. After the HTS test up to 450 K, the forward
${I}-{V}$
curves exhibit a less than 2% positive shift with almost constant ON-resistance and turn-on voltage; the withstand voltage is still up to 600 V without a sharp increase in
${I}_{\text {R}}$
; and the fluctuations of extracted reverse recovery time/charge (
${T}_{\text {rr}}/{Q}_{\text {rr}}{)}$
are less than 5%. The fabricated large-size RESURF
$\beta $
-Ga2O3 SBD achieves good compressive performance and thermal stability, showing the great potential in high power applications under high-temperature condition.