US 6,548,359 B1 · Asymmetrical devices for short gate length performance with disposable sidewall

Abstract

An asymmetrical channel implant from source to drain improves short channel characteristics. The implant provides a relatively high VT net dopant adjacent to the source region and a relatively low VT net dopant in the remainder of the channel region. One way to achieve this arrangement with disposable gate processing is to add disposable sidewalls inside the gate opening (after removing the disposable gate), patterning to selectively remove the source or gate side sidewalls, implant the source and drain regions and remove the remaining sidewall and the proceed. According to a second embodiment, wherein the channel implant can be symmetrical, a relatively low net VT implant is provided in the central region of the channel and a relatively high net VT implant is provided in the channel regions adjacent to the source and drain regions.

Claims17

Dependent claims

A method of fabricating a transistor which comprises the steps of:

(a) providing a semiconductor substrate having a surface and having a first source/drain region and a second source/drain region spaced apart from each other and extending to said surface;
and
(b) providing a channel region disposed in said substrate between said first and second source/drain regions in said substrate and extending to said surface, said channel region having a first dopant profile in a first region of said channel region to provide a first VT and a second dopant profile different from said first dopant profile in a second region of said channel region between said first region and said first source/drain region to provide a second VT different from said first VT, the second dopant profile comprising an implant disposed between said first region and said first source/drain region.

Dependencies are inferred from the claim text.

Asymmetrical devices for short gate length performance with disposable sidewall

Life of this patent

Asymmetrical devices for short gate length performance with disposable sidewall

Life of this patent

Abstract

Claims17