Patent Number: 6,309,935

Title: Methods of forming field effect transistors

Abstract: Methods of forming field effect transistors. In one aspect, a method offorming a field effect transistor includes: a) providing a gate structureover a semiconductor substrate, the gate structure comprising aconductively-doped polysilicon region and a dopant masking cap over theconductively-doped polysilicon region; b) providing a layer of polysiliconover the substrate and over the dopant masking cap of the gate structure,the polysilicon layer defining a pair of polysilicon outward projectionsextending from the semiconductor substrate adjacent the gate structure; c)removing the layer of polysilicon from over the dopant masking cap; d)while the dopant masking cap is over the polysilicon region, conductivelydoping the pair of polysilicon projections with one of an n-type or ap-type conductivity enhancing dopant impurity; and e) out-diffusing theone of the n-type conductivity enhancing dopant impurity or the p-typeconductivity enhancing dopant impurity from the pair of polysiliconprojections into the semiconductor substrate to provide one of NMOS orPMOS type diffusion regions, respectively, within the substrate adjacentthe gate line.

Inventors: Wu; Jeff Zhiqiang (Meridian, ID), Yoganathan; Sittampalam (Boise, ID)


International Classification:

Expiration Date: 10/32013