Deep level transient spectroscopy and pulse height measurements on high resolution n-type 4H-SiC epitaxial schottky barrier radiation detectors

Abstract

High resolution 20 μm n-type 4H-SiC epitaxial layer Schottky barrier radiation detectors were fabricated by depositing nickel (Ni) contacts using DC sputtering for both front- and backside. Current-Voltage (I-V) measurements at 300 K showed barrier height and diode ideality factor of ~1.14 eV and 1.19 respectively. The leakage current at -170 V reverse bias was ~1.0 × 10 -9 A. Capacitance-Voltage (C-V) measurements revealed a doping concentration of 2.9 × 10 14 cm -3 . Deep level transient spectroscopy (DLTS) was carried out to investigate defect levels and capture cross sections. Shallow and deep level defects at Ec - (0.14 ± 0.01) eV, Ec - (0.18 ± 0.01) eV, Ec - (0.62 ± 0.02) eV, Ec - (1.42 ± 0.04) eV, and Ec - (1.52 ± 0.03) eV have been found. A 0.1 μCi 241 Am radiation source was used to assess the detector performance by pulse height spectroscopy (PHS) and the detector showed energy resolution of 0.38% full-width half maxima (FWHM) for alpha particles at 5447 keV.