Lifetime Control in SiC PiN Diodes Using Radiation Defects

Abstract

Application of radiation defects for lifetime control in contemporary SiC PiN diodes was investigated using the calibrated device simulator ATLAS from Silvaco, Inc. Recombination models accounting for the effect of deep levels introduced by the irradiation were set according to experimental results obtained by C-V and DLTS measurements performed on low-doped n-type SiC epilayers irradiated with 4.5 MeV electrons and 670 keV protons. Global (4.5 MeV electron irradiation) and local (700 keV proton irradiation) lifetime reduction was then applied on the 2A/10kV SiC PiN diode and the ON-state and reverse recovery characteristics were simulated and compared. Results show that the proton irradiation can substantially improve the trade‑off between the diode ON‑state and turn‑OFF losses. Compared to the electron irradiation, the local lifetime killing by protons allows achieving better trade-off and softer recovery curves.

Improved reverse recovery characteristics obtained in 4H‐SiC double‐trench superjunction MOSFET with an integrated p‐type Schottky diode

“…Smooth recovery of needs lower with reduced minority carrier charge in the drift region, which can be achieved with the proposed device. Lower and higher soft factor without any carrier lifetime killing technique [18] makes it feasible for high‐frequency applications with more reliability. Table 1 lists the summary of reverse recovery characteristics obtained for temperature ranging from 300 to 500 K. Fig.…”

Displacement damage and total ionisation dose effects on 4H‐SiC power devices

“…the number of defects produced by the projectile, are higher in 4H‐SiC than in Si. More than a tenth of the primary damage (Frenkel's pairs) is transformed into stable defects [38, 42, 43]. Dominant defects (Z1/Z2 and E1–E3 centres) have a character of deep acceptors.…”

“…On the other hand, the lifetime reduction caused by recombination centres introduced by irradiation decreases the charge, which is accumulated in the diode during its ON‐state operation. The irradiated PiN diode then turns OFF faster, and dynamic losses caused by commutation decrease significantly [42].…”

Низкотемпературный отжиг слаболегированных слоев n-4H-SiC после облучения быстрыми электронами

“…Для n-SiC долгое время эта тема считалась недостаточно актуальной, тaк как основные радиационные дефекты Z1/Z2 и EH6/7 отжигаются при температурах ∼ 1000 • С [5][6][7]. Однако в последнее время стали появляться сообщения, свидетельствующие о некой низкотемпературной нестабильности радиационных дефектов, в частности введенных в n-4H-SiC (CVD) при облучении быстрыми электронами [8][9][10][11]. В представленных ранее работах исследования нестабильности проводились либо при определенной температуре отжига, либо в узком диапазоне температур (см., например, [8]).…”