Neutron radiation effect on 4H-SiC MESFETs and SBDs

Abstract

4H-SiC metal Schottky field effect transistors (MESFETs) and Schottky barrier diodes (SBDs) were irradiated at room temperature with 1 MeV neutrons. The highest neutron flux and gamma-ray total dose were 1 × 1015 n/cm2 and 3.3 Mrad(Si), respectively. After a neutron flux of 1 × 1013 n/cm2, the current characteristics of the MESFET had only slightly changed, and the Schottky contacts of the gate contacts and the Ni, Ti/4H-SiC SBDs showed no obvious degradation. To further increase the neutron flux, the drain current of the SiC MESFET decreased and the threshold voltage increased. φB of the Schottky gate contact decreased when the neutron flux was more than or equal to 2.5 × 1014 n/cm2. SiC Schottky interface damage and radiation defects in the bulk material are mainly mechanisms for performance degradation of the experiment devices, and a high doping concentration of the active region will improve the neutron radiation tolerance.