US Patent 7629655 Semiconductor device with multiple silicide regions

A system and method for forming a semiconductor device with a reduced source/drain extension parasitic resistance is provided. An embodiment comprises implanting two metals (such as ytterbium and nickel for an NMOS transistor or platinum and nickel for a PMOS transistor) into the source/drain extensions after silicide contacts have been formed. An anneal is then performed to create a second silicide region within the source/drain extension. Optionally, a second anneal could be performed on the second silicide region to force a further reaction. This process could be performed to multiple semiconductor devices on the same substrate.