Silicidation and deep source-drain formation prior to source- drain extension formation

摘要

A process in accordance with the invention minimizes the number of heat steps to which an source-drain extension region is exposed, thus minimizing source-drain extension region diffusion and allowing more precise control of source-drain extension region thickness over conventional processes. In accordance with the invention, spacers are formed abutting the gate and then heavily doped source and drain regions are formed. The gate and source and drain regions are silicided. The spacers are subsequently removed and source-drain extension regions are then formed. In one embodiment of the invention, a laser doping process is used to form the source-drain extension regions.