Impact of 10 MeV Proton Irradiation on the Electrical Characteristics of Diamond Schottky and Heterojunction Diodes

The radiation tolerance of single-crystal diamond devices was investigated under 10 MeV proton irradiation. Schottky barrier diodes (SBDs) and ITO/diamond heterojunction diodes were fabricated on boron-doped diamond substrates with a 10 μm lightly doped drift layer and exposed to proton fluences from 1.0 × 10 13 to 1.6 × 10 14 cm −2 . Irradiation induced increased on-resistance, reduced saturation current, and enhanced reverse leakage, with heterojunction devices showing greater degradation due to the vulnerability of the ITO layer and interface. Capacitance–voltage measurements revealed carrier removal rates of 171, 65, and 43 cm −1 for fluences of 1.0 × 10 13 , 6.0 × 10 13 , and 1.6 × 10 14 cm −2 , respectively, confirming diamond’s superior radiation hardness compared to Si, GaN, and Ga 2 O 3 . This resilience is attributed to diamond’s high atomic displacement energy, which limits lattice damage. These results demonstrate the potential of single-crystal diamond devices for radiation-hard power electronics and high-radiation environments.