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US 5,760,440 AGranted
Back-source MOSFET
AssigneeFuji Electric Co., Ltd.
InventorsAkio Kitamura, Naoto Fujishima
Life of this patent
Estimating the term…
Abstract
A back-source MOSFET uses a source electrode on a second surface of a substrate to reduce noise which would otherwise interfere with the logic circuit of a power integrated circuit. One embodiment includes a substrate of a first conductivity type and a base layer of a second conductivity type on a first surface of the substrate. A source region is electrically connected with the substrate. A source electrode is formed on a second surface of the substrate. A further embodiment includes a substrate of a first conductivity type and a base layer of a first conductivity type on a first surface of the substrate. A source electrode is formed on a second surface of the substrate.
Claims20
A back-source MOSFET comprising:
- a semiconductor substrate of a first conductivity type;
- a base layer of a second conductivity type on a first surface of said semiconductor substrate;
- a source region of said first conductivity type in said base layer;
- said source region extending in said base layer to contact said semiconductor substrate;
- a drain drift region of said first conductivity type in said base layer;
- a drain region of said first conductivity type in said drain drift region;
- a gate electrode on a portion of said base layer;
- a gate insulation film interposed between said portion of said base layer extending between said source region and said drain drift region;
- a drain electrode connected to said drain region;
- a source electrode on a second surface of said semiconductor substrate;
- and
- said source electrode being connected to said source region.
9 more elements
A back-source MOSFET comprising:
- a semiconductor substrate of a first conductivity type;
- a base layer of a second conductivity type on a first surface of said semiconductor substrate;
- a source region of said first conductivity type in said base layer;
- said source region disposed in said base layer on an opposing side from said semiconductor substrate;
- a trench from a surface of said source region to said semiconductor substrate;
- a conductor in said trench, whereby said source region and said semiconductor substrate are connected with one another via said conductor;
- a drain drift region of said first conductivity type in said base layer;
- a drain region of said first conductivity type in said drain drift region;
- a gate electrode on a portion of said base layer;
- a gate insulation film interposed between said portion of said base layer extending between said source region and said drain drift region;
- a drain electrode connected to said drain region;
- a source electrode on a second surface of said semiconductor substrate;
- said source electrode being connected to said source region.
10 more elements
A back-source MOSFET comprising:
- a semiconductor substrate of a first conductivity type;
- a base layer of a second conductivity type on a first surface of said semiconductor substrate;
- an insulation film on at least a part of a boundary between said semiconductor substrate and said base layer;
- a source region of said first conductivity type in said base layer;
- said source region extending in said base layer to contact said semiconductor substrate;
- a drain drift region of said first conductivity type in said base layer;
- a drain region of said first conductivity type in said drain drift region;
- a gate electrode on a portion of said base layer;
- a gate insulation film interposed between said portion of said base layer extending between said source region and said drain drift region;
- a drain electrode connected to said drain region;
- a source electrode on a second surface of said semiconductor substrate;
- and
- said source electrode being connected to said source region.
10 more elements
A back-source MOSFET comprising:
- a semiconductor substrate of a first conductivity type;
- a base layer of a second conductivity type on a first surface of said semiconductor substrate;
- an insulation film on at least a part of a boundary between said semiconductor substrate and said base layer;
- a source region of said first conductivity type in said base layer;
- said source region extending in said base layer to contact said semiconductor substrate;
- said source region including a diffusion layer extending from a surface of said base layer to said semiconductor substrate;
- a drain drift region of said first conductivity type in said base layer;
- a drain region of said first conductivity type in said drain drift region;
- a gate electrode on a portion of said base layer;
- a gate insulation film interposed between said portion of said base layer extending between said source region and said drain drift region;
- a drain electrode connected to said drain region;
- a source electrode on a second surface of said semiconductor substrate;
- and
- said source electrode being connected to said source region.
11 more elements
A back-source MOSFET comprising:
- a semiconductor substrate of a first conductivity type;
- a base layer of a second conductivity type on a first surface of said semiconductor substrate;
- an insulation film on at least a part of a boundary between said semiconductor substrate and said base layer;
- a source region of said first conductivity type in said base layer;
- said source region extending in said base layer to contact said semiconductor substrate;
- a trench from a surface of said source region to said semiconductor substrate;
- a diffusion layer including impurity ions diffused from an inner face of said trench, whereby said source region and said semiconductor substrate are connected with one another via said diffusion layer;
- a drain drift region of said first conductivity type in said base layer;
- a drain region of said first conductivity type in said drain drift region;
- a gate electrode on a portion of said base layer;
- a gate insulation film interposed between said portion of said base layer extending between said source region and said drain drift region;
- a drain electrode connected to said drain region;
- a source electrode on a second surface of said semiconductor substrate;
- and
- said source electrode being connected to said source region.
12 more elements
A back-source MOSFET comprising:
- a semiconductor substrate of a first conductivity type;
- a base layer of a second conductivity type on a first surface of said semiconductor substrate;
- an insulation film on at least a part of a boundary between said semiconductor substrate and said base layer;
- a source region of said first conductivity type in said base layer;
- said source region disposed in said base layer on an opposite side from said semiconductor substrate;
- a trench from a surface of said source region to said semiconductor substrate;
- a conductor in said trench whereby said source region and said semiconductor substrate are connected with one another via said conductor;
- a drain drift region of said first conductivity type in said base layer;
- a drain region of said first conductivity type in said drain drift region;
- a gate electrode on a portion of said base layer;
- a gate insulation film interposed between said portion of said base layer extending between said source region and said drain drift region;
- a drain electrode connected to said drain region;
- a source electrode on a second surface of said semiconductor substrate;
- said source electrode being connected to said source region.
11 more elements
A back-source MOSFET comprising:
- a semiconductor substrate of a first conductivity type;
- a base layer of a second conductivity type on a first surface of said semiconductor substrate;
- an insulation film on at least a part of a boundary between said semiconductor substrate and said base layer;
- a source region of said first conductivity type in said base layer;
- said source region disposed in said base layer on an opposite side from said semiconductor substrate;
- a trench extending from a surface of said source region to said semiconductor substrate;
- a conductor in said trench whereby said source region and said semiconductor substrate are connected with one another via said conductor;
- said conductor further connecting said source region and said semiconductor substrate;
- a drain drift region of said first conductivity type in said base layer;
- a drain region of said first conductivity type in said drain drift region;
- a gate electrode on a portion of said base layer;
- a gate insulation film interposed between said portion of said base layer extending between said source region and said drain drift region;
- a drain electrode connected to said drain region;
- a source electrode on a second surface of said semiconductor substrate;
- said source electrode being connected to said source region.
12 more elements
A back-source MOSFET comprising
- a semiconductor substrate of a first conductivity type;
- a base layer of a second conductivity type on a first surface of said semiconductor substrate;
- a drain drift region of said first conductivity type on said base layer;
- a drain region on said drain drift region;
- a trench from a surface of said drain region at least to said semiconductor substrate;
- a conductor, disposed between said base layer and said semiconductor substrate whereby said semiconductor substrate and said base layer are connected with one another by said conductor;
- a gate electrode in said trench;
- a gate oxide film between said gate electrode and said base layer;
- said gate electrode and said base layer facing opposite surfaces of said gate oxide film;
- a source electrode on a second surface of said semiconductor substrate;
- and
- a drain electrode connected to said drain region.
9 more elements
A back-source MOSFET comprising:
- a semiconductor substrate of a first conductivity type;
- a base layer of said first conductivity type on a first surface of said semiconductor substrate;
- a drain drift region of said first conductivity type formed directly on said base layer;
- a drain region on said drain drift region;
- a trench from a surface of said drain region at least to said semiconductor substrate;
- a gate electrode in said trench;
- a gate oxide file between said gate electrode and said base layer;
- said gate electrode and said base layer facing opposite surfaces of said gate oxide film;
- a source electrode on a second surface of said semiconductor substrate;
- and
- a drain electrode connected to said drain region;
- whereby a normally-on switch is formed.
9 more elements
Dependencies are inferred from the claim text.