Method of fabricating a semiconductor device with field-effect transistors having shallow source and drain junctions

Abstract

A field-effect transistor is fabricated by depositing and patterning a layer of a semiconductor material and a first dielectric film to form a gate electrode covered by the remaining part of the first dielectric film, depositing a second dielectric film to form sidewalls on the gate electrode and first dielectric film, implanting a first impurity into the substrate to form source and drain regions, forming a third dielectric film masking at least the inner parts of the source and drain regions while exposing the first dielectric film, removing the first dielectric film by etching, and implanting a second impurity into the gate electrode. The first and second impurities may be, for example, boron difluoride and boron, respectively. The implantation parameters can be adjusted to form shallow source and drain regions and form a fully doped gate electrode.