Evolution of {311} type defects in boron-doped structures: Experimental evidence of boron–interstitial cluster formation

Boron-doped well structures formed in Czochralski silicon are subjected to a self-implant and various anneals to form a population of type {311} defects. Quantitative transmission electron microscopy is then used to measure the residual interstitials trapped in the {311} defects as a function of boron concentration and anneal temperature. We have found a strong tendency for increased dissolution rates of {311} type defects at boron concentrations above 1018 cm−3, providing direct evidence for the formation of boron–interstitial clusters. By profiling the samples with secondary ion mass steptroscopy and comparing the results to spreading resistance measurements the degree of deactivation can be determined.