Influence of heavy ion irradiation and high temperature on the performance of 4H–SiC Schottky barrier α particle detector

Abstract

Traditional semiconductor detectors such as silicon and germanium are easily affected by ambient temperature and charge-particle ion's radiation. They can't work stably in harsh environments such as high temperature and strong radiation for a long time. In this paper, 4H-silicon carbide detectors based on a Schottky barrier diode (SBD) were fabricated and the combined influences of high temperatures and heavy ion irradiation on 4H–SiC detectors have been investigated. With no radiation, the 4H–SiC detectors have excellent I–V characteristics performance during a temperature range of 30–200 °C. Even at an ambient temperature of 200 °C, the leakage current of the 4H–SiC detector was only 107 nA at the full depletion voltage. Then 280 KeV C4+ heavy ions were used to irradiate the 4H-silicon carbide detectors, and the performances of the irradiated detectors were studied for different radiation doses from 1 × 1013 to 1 × 1016 ions/cm2 in a certain higher ambient temperature environment. For the fully depleted 4H-silicon carbide detectors in an ambient temperature of 140 °C, both the I–V characteristics and the energy resolution have shown a certain radiation damage at the radiation fluence of 1 × 1015 ions/cm2, while a significant deterioration was observed when the radiation fluence is up to 1 × 1016 ions/cm2. It means that the 4H–SiC detectors can withstand an irradiation dose of 1 × 1015 ions/cm2 at 140 °C. The time-dependent I–V curves were also investigated for the irradiated detectors for a standing time up to 192 h, and it's found that the irradiated detectors had minor changes in the leakage currents during a long time standing. A PN junction model with current and voltage equations was used to explain the phenomenon that the reverse leakage current increases with the increase of temperature. The surface recombination model was also used to explain the deterioration of I–V characteristics and energy resolution after irradiation.