US 7,405,128 B1 · Dotted channel MOSFET and method

Abstract

A improved MOSFET (50, 51, 75, 215) has a source (60) and drain (62) in a semiconductor body (56), surmounted by an insulated control gate (66) located over the body (56) between the source (60) and drain (62) and adapted to control a conductive channel (55) extending between the source (60) and drain (62). The insulated gate (66) is perforated by a series of openings (61) through which highly doped regions (69) in the form of a series of (e.g., square) dots (69) of the same conductivity type as the body (56) are provided, located in the channel (55), spaced apart from each other and from the source (60) and drain (62). These channel dots (69) are desirably electrically coupled to a highly doped contact (64) to the body (56). The resulting device (50, 51, 75, 215) has a greater SOA, higher breakdown voltage and higher HBM stress resistance than equivalent prior art devices (20) without the dotted channel. Threshold voltage is not affected.

Claims7

Dependent claims

A method for forming a dotted channel field effect device, comprising:

providing a semiconductor substrate of a first conductivity type and having a surface;
forming a well region of a second, opposite, conductivity type in a first part of the substrate extending to the surface;
forming a body region of the first conductivity type in a second part of the substrate extending to the surface and in contact with or spaced apart from the well region;
forming a control gate insulated from the surface over at least a portion of the body region and having therein multiple holes extending through the control gate and located over the portion of the body region;
forming multiple highly doped regions of the first conductivity type in the body region through the multiple holes;
forming source and drain regions of the second, opposite, conductivity type in the substrate on either side of the control gate;
and
providing electrical terminals to the source, drain, control gate and the multiple highly doped regions.

5 more elements

Dependencies are inferred from the claim text.

Dotted channel MOSFET and method

Life of this patent

Dotted channel MOSFET and method

Life of this patent

Abstract

Claims7