this invention adds to the art of replacement source - drain cmos transistors . processes may involve etching a recess in the substrate material using one equipment set , then performing deposition in another . disclosed is a method to perform the etch and subsequent deposition in the same reactor without atmospheric exposure . in - situ etching of the source - drain recess for replacement source - drain applications provides several advantages over state of the art ex - situ etching . transistor drive current is improved by : eliminating contamination of the silicon - epilayer interface when the as - etched surface is exposed to atmosphere and precise control over the shape of the etch recess . deposition may be done by a variety of techniques including selective and non - selective methods . in the case of blanket deposition , a measure to avoid amorphous deposition in performance critical regions is also presented .