Optimization of ClusterCarbon™ process parameters for strained Si lattice

We present here the substitutional carbon dependence of ClusterCarbon implant energy and dose, and anneal parameters such as solid phase epitaxial regrowth (SPER) temperature and various high temperature millisecond flash anneal conditions. With a multiple implant sequence of carbon implants one can obtain a fairly uniform carbon profile and we show that it provides better carbon substitution [C]sub when compared to a single implant. It is been established that optimizing the percentage of [C]sub requires an SPER anneal temperature <850 °C followed by a millisecond anneal. We show that carbon substitution increases with SPER temperature up to 800 °C and decreases beyond this temperature supporting the fact that carbon has a significant probability of being excited out of its substitutional site beyond 850 °C. We report here that SPER anneal with an additional millisecond flash anneal that provides highest carbon substitution, [C]subs > 2%. For a given millisecond anneal and for implants with various energies and doses we show that the percentages of [C]sub increases linearly with the fraction of carbon dopants within the amorphous layer.