A method of manufacturing a MOS transistor is provided. A gate insulation layer and a conductive layer are sequentially formed over a substrate. A pre-amorphization implantation is carried out to amorphize the conductive layer. The conductive layer and the gate insulation layer are patterned to form a gate structure. A first spacer is formed on the sidewall of the gate structure. A second pre-amorphization implantation is carried out to amorphize a portion of the substrate. A doped source/drain extension region is formed in the substrate on each side of the first spacer. A second spacer is formed on the sidewall of the first spacer and then a doped source/drain region is formed in the substrate on each side of the second spacer. A solid phase epitaxial process is carried out to convert the doped source/drain extension region and the doped source/drain region into a source/drain terminal. In the pre-amorphization implantations, dopants having an ionic radius greater than the germanium ion are used.
A method of manufacturing a semiconductor device includes forming a gate, source/drain extensions, buffer regions, and source/drain regions. The gate is formed over a semiconductor layer, and the source/drain extensions are formed within the semiconductor layer and adjacent the gate. The buffer regions are formed within first amorphous implant regions, and the source/drain regions are formed within second amorphous implant regions. The buffer regions and the source/drain regions are activated using solid-phase epitaxy whereby sidewalls of the activated buffer regions and the activated source/drain regions are substantially vertical.