Sanken Electric Co., Ltd.

Polar Semiconductor, Inc.

Tatsuya Kamimura

Peter West

Don Rankila

Steven L Kosier

Dosi Dosev

Shunsuke Fukunaga

Steve Kosier

A trench semiconductor device includes a layer of semiconductor material, an exterior trench pattern formed in the layer of semiconductor material, and an interior trench pattern formed in the layer of semiconductor material, at least partially surrounded by the exterior trench pattern. The exterior trench pattern includes a plurality of exterior trench portions that are each lined with dielectric material and filled with conductive material, and the interior trench pattern includes a plurality of interior trench portions that are each lined with dielectric material and filled with conductive material.

Trench semiconductor device layout configurations

Apparatus and associated methods relate to a bond-pad structure having small pad-substrate capacitance for use in high-voltage MOSFETs. The bond-pad structure includes upper and lower polysilicon plates interposed between a metal bonding pad and an underlying semiconductor substrate. The lower polysilicon plate is encapsulated in dielectric materials, thereby rendering it floating. The upper polysilicon plate is conductively coupled to a source of the high-voltage MOSFET. A perimeter of the metal bonding pad is substantially circumscribed, as viewed from a plan view perspective, by a perimeter of the upper polysilicon plate. A perimeter of the upper polysilicon plate is substantially circumscribed, as viewed from the plan view perspective, by a perimeter of the lower polysilicon plate. In some embodiments, the metal bonding pad is conductively coupled to a gate of the high-voltage MOSFET. The pad-substrate capacitance is advantageously made small by this bond-pad structure.

High-voltage MOSFET structures

Apparatus and associated methods relate to a bonding pad structure for a trench-based semiconductor device. The bonding pad structure reduces a peak magnitude of the electric field between a metal bonding pad and the underlying semiconductor. The bonding pad structure includes a plurality of trenches vertically extending from a top surface of a semiconductor. Each of the plurality of trenches has dielectric sidewalls and a dielectric bottom, the dielectric sidewalls and dielectric bottom electrically isolating a conductive core within each of the trenches from a region of semiconductor outside of and adjacent to each of the plurality of trenches. The bonding pad structure includes a metal bonding pad disposed above the plurality of trenches, the metal bonding pad electrically isolated from the region of semiconductor outside of the trenches. The conductive core can be biased to reduce the magnitude of the field between adjacent trenches.

High voltage tolerant bonding pad structure for trench-based semiconductor devices

Apparatus and associated methods relate to an edge-termination structure surrounding a high-voltage MOSFET for reducing a peak lateral electric field. The edge-termination structure includes a sequence of annular trenches and semiconductor pillars circumscribing the high-voltage MOSFET. Each of the annular trenches is laterally separated from the other annular trenches by one of the semiconductor pillars. Each of the annular trenches has dielectric sidewalls and a dielectric bottom electrically isolating a conductive core within each of the annular trenches from a drain-biased region of the semiconductor pillar outside of and adjacent to the annular trench. The conductive core of the innermost trench is biased, while the conductive cores of one or more outer trenches are floating. In some embodiments, a surface of an inner semiconductor pillar is biased as well. The peak lateral electric field can advantageously be reduced by physical arrangement of trenches and electrical biasing sequence.

Growing community of inventors

St. Louis Park, MN, United States of America

Tatsuya Kamimura