Lateral double-diffused mosfet
AssigneeNissan Motor Co., Ltd.
InventorsMasakatsu Hoshi, Teruyoshi Mihara
Life of this patent
Estimating the term…
Abstract
A lateral double-diffused MOSFET has a semiconductor substrate, a drain region formed on the substrate, a gate insulation film formed on the drain region, a gate electrode formed on the gate insulation film, source and drain openings formed through the gate electrode, a first conductive region formed under the drain region, a source electrode formed on the source openings, a drain electrode formed on the drain openings, and second conductive regions for connecting the drain electrode to the first conductive region. The source and drain openings are cyclically arranged so that at least two rows of source openings are arranged between adjacent drain openings, to reduce the ON resistance of the MOSFET.
Claims16
A power LDMOSFET having a multiplicity of unitcells, each of said unitcells comprising:
- a semiconductor substrate of a first conductivity type,
- a first conductive region formed on the semiconductor substrate,
- a drain region of a second conductivity type formed on the first conductive region,
- a gate insulation film formed on the surface of the drain region,
- a gate electrode formed on the gate insulation film,
- a drain opening formed through the gate electrode, a source opening array arranged in a form of a concentric polygonal ring surrounding the drain opening, the concentric polygonal ring including at least two polygonal rings having a plurality of source openings arranged on the at least two polygonal rings, the source openings formed through the gate electrode, and each ring of the at least two polygonal rings being arranged to have a predetermined spacing therebetween,
- a base region of the first conductivity type formed under each of the source openings,
- a source region of the second conductivity type formed in each of the base regions,
- a plurality of source electrodes formed on and in contact with the source regions,
- a drain contact region formed under the drain opening,
- a second conductive region of low resistance to electrically connect the first conductive region to the drain contact region,
- a first drain electrode formed on and in contact with the drain contact region, and
- an insulation interlayer formed on the source regions, and a second drain electrode formed on the insulation interlayer and electrically connected to the first drain electrode.
A power LDMOSFET comprising:
- a semiconductor substrate of a first conductivity type,
- a first conductive region formed on the semiconductor substrate,
- a drain region of a second conductivity type formed on the first conductive region,
- a gate insulation film formed on a surface of the drain region,
- a gate electrode formed on the gate insulation film, at least two drain openings formed through the gate electrode,
- a source opening array arranged in a form of a polygonal ring surrounding each of the drain openings, the source opening array comprising a plurality of source openings formed through the gate electrode, the source openings arranged on the polygonal ring,
- a base region of the first conductivity type formed under each of the source openings,
- a source region of the second conductivity type formed in each of the base regions,
- a plurality of source electrodes formed on and in contact with the source regions,
- a drain contact region formed under each of the drain openings,
- a second conductive region of low resistance to electrically connect the first conductive region to each of the drain contact regions,
- a first drain electrode formed on and in contact with each of the drain contact regions,
- an insulation interlayer formed on the source regions, and
- a second drain electrode formed on the insulation interlayer and electrically connected to the first drain electrode,
- wherein the respective polygonal rings are arranged to have a predetermined spacing therebetween, and the predetermined spacing is selected such that depletion layers expanding from the base regions do not increase a resistance in the drain region.
Dependencies are inferred from the claim text.