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. φ_B 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.

Key words: silicon carbide, metal Semiconductor field effect transistor, Schottky barrier diode, neutron radiation