Poly recessed fabrication method for defining high performance MOSFETS

摘要

A method for forming a gate conductor by using a masking layer above a polysilicon layer to define the length of a gate is presented. The length of the gate may be adjusted by the use of spacers. The method includes forming a plurality of layers including a dielectric layer, a polysilicon layer and a masking layer. An opening is preferably formed in the masking layer, the opening defining the location of the gate conductor. The width of the opening may be narrowed by the use of spacers. A portion of the polysilicon layer defined by the opening is implanted with an n-type impurity. An oxide layer is formed over the implanted portion of the polysilicon layer. The polysilicon layer is etched such that a gate conductor is formed underneath the oxide layer. LDD areas and source/drain areas are subsequently formed adjacent to the gate conductor.