Semiconductor device having multiple thickness nickel silicide layers

A method of manufacturing a semiconductor device includes providing a gate electrode having first and second opposing sidewalls over a substrate having source/drain regions; forming first and second sidewall spacers respectively disposed adjacent the first and second sidewalls; and forming first and second nickel silicide layer respectively disposed on the source/drain regions and the gate electrode. The nickel silicide layer over the gate electrode can be thicker than the nickel silicide layer over the source/drain regions. A semiconductor device formed from the method is also disclosed.