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 1×1015 cm−2 and annealed at 900 or 1100 °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 °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 °C anneal. At 1100 °C part of the C–Si complexes dissolve and the electrical characteristics of the materials noticeably improve.