Apparatus and method for source side implantation after spacer formation to reduce short channel effects in metal oxide semiconductor field effect transistors

The present invention provides an apparatus and method for a metal oxide semiconductor field effect transistor (MOSFET) fabricated to reduce short channel effects. The MOSFET includes a semiconductor substrate, a gate stack formed above the semiconductor substrate, a drain side sidewall spacer formed on a drain side of the gate stack, a source side sidewall spacer formed on a source side of the gate stack, and source and drain regions. The source region is formed in the semiconductor substrate on the source side, and is aligned by the source side sidewall spacer to extend an effective channel length between the source region and drain region. The drain region is formed on the drain side in the semiconductor substrate, and is aligned by drain side sidewall spacer to further extend the effective channel length.