ELECTRON-IRRADIATION OF ION-IMPLANTED N-TYPE SI-SIO2 STRUCTURES STUDIED BY DEEP-LEVEL TRANSIENT SPECTROSCOPY

The effect of 12-MeV electron irradiation on Si-SiO2 structures implan ted with 50-keV boron ions is studied by deep-level transient spectros copy (DLTS) measurements. The DLTS spectra of ion-implanted samples ex hibit one peak which corresponds to a deep level located in the forbid den gap of the silicon matrix at E-c -0.40 eV below the conducting ban d edge. New additional shallower levels are found in the spectra follo wing bombardment by high-energy electrons, the peak intensity being de pendent on the irradiation dose. The corresponding activation energy o f the created defects, the density of the traps, and the electron-capt ure cross sections are evaluated.