US Patent 7867861 Semiconductor device employing precipitates for increased channel stress

A method for fabricating a semiconductor device including implanting a selected material at a desired target depth below a surface of a silicon substrate, performing an annealing process to create a band of precipitates formed from the selected material and the silicon of the silicon substrate at the desired target depth, and forming a source region and a drain region in the substrate such that a channel region there between is positioned above the band of precipitates, wherein the desired target depth is such that a desired separation distance is achieved between the channel region and the band of precipitates, and wherein an average lattice constant of the band of precipitates is different from the average lattice constant of the silicon substrate so as to cause a stress in the channel region.