HIGH-TEMPERATURE ANNEALING EFFECTS ON THE ELECTRICAL CHARACTERISTICS OF C IMPLANTED SI

We have investigated the electrical characteristics of p(+)-n Si junct ion diodes implanted with 300 keV C ions at fluences of 0.5 and 1x10(1 5) cm(-2) and annealed at 900 or 1100 degrees C. In all cases cross-se ctional transmission electron microscopy shows an excellent crystallin e quality, with no extended defects, and the C-rich region is characte rized by an n-type doping. In the material annealed at 900 degrees C t he C-rich region shows a low electron mobility and the presence of dee p donor levels, and, as a consequence, the diode characteristics are n onideal. These effects can be attributed to the formation of C-Si self -interstitial-type complexes after the 900 degrees C anneal. At 1100 d egrees C part of the C-Si complexes dissolve and the electrical charac teristics of the materials noticeably improve. (C) 1996 American Insti tute of Physics.