Fairchild Semiconductor Corporation

Intersil Corporation

Joseph L Cumbo

Thomas E Grebs

Christopher Boguslaw Kocon

Rodney S Ridley

Jeffrey P Spindler

Jeffrey Edward Lauffer

Rodney Sylvester Ridley, Sr

A method for forming trenches in a device layer disposed on a silicon semiconductor substrate comprises: covering the device layer with an etch resistant masking layer to define at least two trench regions; removing semiconductor material from the exposed trench regions by applying an etching agent that selectively etches the semiconductor substrate with respect to the trench masking layer, thereby forming at least two trenches each comprising a floor and sidewalls; and, during the removal of semiconductor material, exposing the sidewalls to a passivating agent in increasing amounts, thereby passivating the sidewalls while reducing lateral etching of semiconductor material from them.

Trench etch with incremental oxygen flow

A process for constructing a trench MOS-gated device includes: forming in a semiconductor substrate an extended trench that comprises an upper segment and a bottom segment, wherein the bottom segment has a lesser width relative to a greater width of the trench upper segment and extends to a depth corresponding to the total depth of the extended trench. The bottom segment of the trench is substantially filled with dielectric material. The trench upper segment has a floor and sidewalls comprising dielectric material and is substantially filled with a conductive material to form a gate region. A heavily doped source region of the first conduction type and a heavily doped body region of the second conduction type are formed in a surface well region on the side of the extended trench opposite an extended doped zone.

Process for forming MOS-gated power device having segmented trench and extended doping zone

A trench MOS-gated device comprises a doped monocrystalline semiconductor substrate that includes an upper layer and is of a first conduction type. An extended trench in the substrate in the upper layer comprises two segments having differing widths relative to one another: a bottom segment of lesser width filled with a dielectric material, and an upper segment of greater width lined with a dielectric material and substantially filled with a conductive material, the filled upper segment of the trench forming a gate region. An extended doped zone of a second opposite conduction type extends from an upper surface into the upper layer of the substrate only on one side of the trench, and a doped well region of the second conduction type overlying a drain zone of the first conduction type is disposed in the upper layer on the opposite side of the trench.

MOS-gated power device having segmented trench and extended doping zone and process for forming same

A semiconductor device includes a source region and a gate disposed at the upper surface of a silicon substrate, which includes a drain region for the device. On the lower surface of the substrate is disposed a backmetal drain terminal comprising a stack that includes a first layer of tantalum and an outermost second layer of copper.

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West Wyoming, PA, United States of America

Joseph L Cumbo