Abstract: In one aspect, a method includes depositing a first glass layer on a metallization layer and depositing an etch stop layer on the first glass layer. The method further includes depositing a second glass layer on the etch stop layer and polishing the second glass layer down to at least a surface of the etch stop layer.

Abstract: In one aspect, a method of fabricating a transistor includes depositing a first epitaxial layer; depositing a second epitaxial layer on the first epitaxial layer; forming a single termination trench in the second epitaxial layer; and filling the termination trench with a dielectric. A depth of the termination trench is greater than 10 microns. In another aspect, a transistor includes a first epitaxial layer; a second epitaxial layer on the first epitaxial layer; and a single termination trench in the second epitaxial layer. The termination trench is greater than 10 microns and is filled with a dielectric.

Abstract: In one aspect, a method includes depositing a first glass layer on a metallization layer and depositing an etch stop layer on the first glass layer. The method further includes depositing a second glass layer on the etch stop layer and polishing the second glass layer down to at least a surface of the etch stop layer.

Abstract: In one aspect, a method of fabricating a transistor includes depositing a first epitaxial layer; depositing a second epitaxial layer on the first epitaxial layer; forming a single termination trench in the second epitaxial layer; and filling the termination trench with a dielectric. A depth of the termination trench is greater than 10 microns. In another aspect, a transistor includes a first epitaxial layer; a second epitaxial layer on the first epitaxial layer; and a single termination trench in the second epitaxial layer. The termination trench is greater than 10 microns and is filled with a dielectric.

Abstract: In one aspect, a method of fabricating a transistor includes implanting ions into a first portion of a second epitaxial layer to form a recombination region, depositing a second portion of the second epitaxial layer having an n-type dopant on the recombination region, and forming trenches in the second portion of the second epitaxial layer.

Abstract: In one aspect, a method of fabricating a transistor includes depositing a first epitaxial layer, depositing a second epitaxial layer on the first epitaxial layer, implanting the second epitaxial layer to form a p-field termination region, depositing a third epitaxial layer on the p-field termination layer and forming trenches in the third epitaxial layer. The trenches include a trench gate of the transistor and a termination trench.

Abstract: 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.

Abstract: In one aspect, a method of fabricating a transistor includes depositing a first epitaxial layer having a first n-type dopant, depositing a first portion of a second epitaxial layer having a second n-type dopant on the first epitaxial layer, implanting ions into the first portion of the second epitaxial layer to form a recombination region, depositing a second portion of the second epitaxial layer having the second n-type dopant on the recombination region, and forming trenches in the second portion of the second epitaxial layer, wherein the trenches comprise a trench gate of the transistor and a termination trench. The second portion of the second epitaxial layer is thicker than the first portion of the second epitaxial layer.

Abstract: In one aspect, a method of fabricating a transistor includes depositing a first epitaxial layer, depositing a second epitaxial layer on the first epitaxial layer, implanting the second epitaxial layer to form a p-field termination region, depositing a third epitaxial layer on the p-field termination layer and forming trenches in the third epitaxial layer. The trenches include a trench gate of the transistor and a termination trench.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Apparatus and associate methods relate to a high-voltage MOSFET bounded by two trenches, each having dielectric sidewalls and a dielectric bottom isolating a top field plate and a bottom field plate. The top field plate is electrically connected to a biasing circuit net, and the bottom field plate is biased via a capacitive coupling to the top field plate. The upper field plate and lower field plate are configured to deplete the majority carriers in a drain region of the MOSFET bounded by the two trenches so as to equalize two local maxima of an electric field induced by a drain/body bias, the two local maxima located proximate a drain/body metallurgical junction and proximate a trench bottom. The two local maxima of the electric field are equalized by controlling a depth location of an intervening dielectric between the upper field plate and the lower field plate.

Abstract: A semiconductor device according to one or more embodiments may include: a drain region; a drift region positioned above the drain region; a base region positioned on the drift region; a trench positioned to abut the base region and the drift region; an insulating in the trench; a counter electrode embedded in the insulating film; a gate electrode positioned above the counter electrode and that is embedded in the insulating film; and a source region that abuts the base region and the trench, wherein a thickness of the insulating film between the gate electrode and an interface between the drift region and the base region is larger than a thickness of the insulating film between the gate electrode and an interface between the source region and the base region.

Abstract: Apparatus and associated methods relate to controlling an electric field profile within a drift region of an LDMOS device using first and second RESURF regions. The first RESURF region extends from a source end toward a drain end of the LDMOS device. The first RESURF region is adjacent to a forms a metallurgical junction with the drift region. The second RESURF layer extends from the drain end toward the source end of the LDMOS device. The second RESURF layer has an end that is longitudinally between the body contact and the source end of the first RESURF layer. A distance between the end of the second RESURF layer and the body contact is greater than a vertical distance between the end of the second RESURF layer and the body contact. A maximum electric field between the second RESURF layer and the body contact can be advantageously reduced with this geometry.

Abstract: Apparatus and associated methods relate to controlling an electric field profile within a drift region of an LDMOS device using biased field plates to deplete majority carriers from a drift region between a body/drift-region metallurgical junction and a drain contact. Such field plates are located in trenches that longitudinally extend within the drift region. Field plates are laterally spaced apart from each other at a distance that permits substantial depletion of majority carriers between adjacent field plates. Trenches have trench bottoms located within a drift-region/substrate metallurgical junction so as to permit substantial depletion of majority carriers between trench bottoms and the drift-region/substrate metallurgical junction. Between adjacent trenches, dopant concentrations can be increased up to a threshold that can be substantially depleted under specified bias conditions.

Abstract: 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.

Abstract: An isolation structure prevents inter-device and intra-device leakage in first and second adjacent semiconductor devices in a substrate. The first and second semiconductor devices each include a gate region and at least one active region. A first channel stop region is configured to surround the first semiconductor device. A second channel stop region is configured to surround the second semiconductor device. A first field plate is located above at least part of the first channel stop region, and overlaps the gate region of the first semiconductor device in a first overlap region. A second field plate is located above at least part of the second channel stop region, and overlaps the gate region of the second semiconductor device in a second overlap region.

Abstract: 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.

Abstract: A method of controlling an etch-pattern density of a polysilicon layer includes depositing polysilicon on a wafer. The method includes determining polysilicon-etch regions that include DMOS source regions within circuit-device areas of the wafer. The method includes calculating an etch area of the polysilicon-etch regions and then comparing the calculated etch area of the polysilicon-etch regions to a predetermined minimum etch area. If the calculated etch area is less than a predetermined threshold, the method adds polysilicon-etch regions within non-circuit-device areas to the determined polysilicon-etch regions within the circuit-device areas until the comparing step results in the calculated etch area of the polysilicon-etch regions being greater than the predetermined minimum etch area. The method includes etching the polysilicon from the polysilicon-etch regions in both the circuit-device areas and the non-circuit-device areas.