Investigation of Electronic States of Pd in 4H-SiC by Means of Radiotracer-DLTS

Abstract

The existence of deep levels of the transition metal Pd localized within the band gap of SiC is investigated. By using radioactive isotopes as tracer atoms, vanishing or arising peaks found in repeated DLTS measurements can be definitely assigned to a certain element due to the known half-life. In the present study, the radioactive isotope 100 Pd was recoil-implanted into 4H-SiC at the ISL of the HMI in Berlin. The isotope 100 Pd decays with a half-life T 1/2 of 3.6 d to 100 Rh (T 1/2 = 20.8 h), which itself decays to stable 100 Ru. A deep level decreasing in concentration during the 100 Pd decay was found at 1.03 eV below the conduction band E c in n-type 4H-SiC. It is definitely assigned to Pd. In p-type 4H-SiC no defect level with time dependent concentration was detected.