Isochronal Annealing Study of Deep Levels in Hydrogen Implanted p-Type 4H-SiC

Abstract

Aluminum doped 4H-SiC samples have been implanted with 200 and 100 keV hydrogen at five different temperatures. An isochronal annealing series has been carried out up to 1000 °C and deep level transient spectroscopy (DLTS) was performed after every annealing step in the 150-700 K temperature range. After studying the role of the annealing treatments on the reactivation of aluminum acceptors, we discuss the results of the DLTS experiment. Eight deep levels were found in the 0.15 - 0.7 eV range above the valence band (E v ), and their annealing behavior, as a function of the temperature is presented. We found that deep levels implanted at temperatures below 300 °C are less thermally stable. Furthermore, we compare the experimental results with theoretical data present in the literature, and suggest a possible microscopic structure of the detected levels.