Recesses are formed in the drain and source regions of an MOS transistor. The recesses are formed using two anisotropic etch processes and first and second sidewall spacers. The recesses are made up of first and second recesses, and the depths of the first and second recesses are independently controllable....http://www.google.de/patents/US7670923?utm_source=gb-gplus-sharePatent US7670923 - Method of fabricating strain-silicon CMOS
