Deep level defects in electron-irradiated 4H SiC epitaxial layers

TLDR

The study investigated the dose dependence and annealing behavior of defects in electron‑irradiated 4H SiC epitaxial layers. Deep level transient spectroscopy was employed to examine defects in CVD‑grown 4H SiC, measuring capture cross sections for two electron traps and assessing dose and annealing effects. Measurements on p⁺/n junctions from 100–750 K revealed several electron traps and one hole trap with ionization energies 0.35–1.65 eV, present even at doses as low as 5 × 10¹³ cm⁻², and the capture cross sections of two defects were temperature independent.

Abstract

Deep level defects in electron-irradiated 4H SiC epitaxial layers grown by chemical vapor deposition were studied using deep level transient spectroscopy. The measurements performed on electron-irradiated p+n junctions in the temperature range 100–750 K revealed several electron traps and one hole trap with thermal ionization energies ranging from 0.35 to 1.65 eV. Most of these defects were already observed at a dose of irradiation as low as ≈5×1013 cm−2. Dose dependence and annealing behavior of the defects were investigated. For two of these electron traps, the electron capture cross section was measured. From the temperature dependence studies, the capture cross section of these two defects are shown to be temperature independent.