Removal of end-of-range defects in Ge+-pre-amorphized Si by carbon ion implantation

Carbon ion implantation was employed to annihilate the end-of-range (EOR) d efects in Ge+-pre-amorphized Si. Experimental results showed that the effic iency of EOR defect removal depends on the Ge+-pre-amorphization conditions , the location of projected range (R-p) of carbon implant and subsequent an nealing conditions. The best defect removal occurred when R-p of carbon imp lantation was brought close to the amorphous/crystalline (a/c) interface ge nerated by Ge+-pre-amorphization. The higher the annealing temperature, the better the interstitial gettering efficiency of carbon atoms was observed. However, transmission electron microscopy investigation revealed the emerg ence of hairpin dislocations when dose and accelerating voltage of Ge+ impl antation were high. In specimens without carbon implantation, the hairpin d islocations could be readily removed by a 900 degrees C, 30 min anneal. For carbon-implanted specimens, the density of hairpin dislocations increased when R-p of carbon implantation was close to the (a/c) interface. The glide motion of hairpin dislocations was affected by Ge+-pre-amorphization condi tions and was inhibited by the SiC complexes formed in the vicinity of disl ocations so that they became rather difficult to anneal out of the specimen s. (C) 1999 American Institute of Physics. [S0021-8979(99)06306-9].