US Patent 9093514 Strained and uniform doping technique for FINFETs

The present disclosure relates to a device and method of forming enhanced channel carrier mobility within a transistor. Silicon carbon phosphorus (SiCP) source and drain regions are formed within the transistor with cyclic deposition etch (CDE) epitaxy, wherein both resistivity and strain are controlled by substitutional phosphorus. A carbon concentration of less than approximately 1% aids in control of the phosphorus dopant diffusion. Phosphorus dopant diffusion is also controlled by an anneal step which promotes uniform doping through both source and drain, as well as lightly-doped drain regions.