Electrical characterization of proton irradiated p+p+–n–n+n+ Si diode

Electrical characterization of p+p+–n–n+n+ Si power electric diodes was done with proton irradiation. The kinetic energies of irradiated protons were 2.32, 2.55 and 2.97 MeV, and for each energy condition, doses of 1×10111×1011, 1×10121×1012 and 1×1013cm-2 were given. By modulating the kinetic energy, the proton penetration depth into Si crystal could be adjusted to the range of 55–90μm, and then controlled to the special depth regions such as junction region, depletion region and neutral region over the depletion layer in the p+p+–n–n+n+ diode structure. Defects produced by the proton irradiation affected to electrical property of the Si diode because of their carrier trapping, and then the reverse recovery time was improved from 240 to 50 ns. It appeared that the defect states with activation energies of 0.47 and 0.54 eV may be responsible for the decrease of the minority carrier lifetime in the proton-irradiated diode with 2.97 MeV energy and 1×1013cm-2 doses.