High temperature annealing effects on the electrical characteristics of C implanted Si

We have investigated the electrical characteristics of p(+)-n Si junction diodes implanted with 300 keV C ions at fluences of 0.5 and 1x10(15) cm(-2) and annealed at 900 or 1100 degrees C. In all cases cross-sectional transmission electron microscopy shows an excellent crystalline quality, with no extended defects, and the C-rich region is characterized by an n-type doping. In the material annealed at 900 degrees C the C-rich region shows a low electron mobility and the presence of deep donor levels, and, as a consequence, the diode characteristics are nonideal. These effects can be attributed to the formation of C-Si self-interstitial-type complexes after the 900 degrees C anneal. At 1100 degrees C part of the C-Si complexes dissolve and the electrical characteristics of the materials noticeably improve