Abstract: A low voltage power device includes a plurality of quasi-vertical LDMOS device cells. A conductive trench sinker is formed through the epitaxial layer and adjacent a selected one of the source and drain regions in each cell. The trench sinker electrically couples the selected one of the source and drain regions to the substrate for coupling current from the channel to the substrate. The resulting device exhibits a vertical current flow between the metal electrode covering the front surface and the second electrode formed at the back side of the wafer. The device cells are arranged in a closed cell configuration.

Abstract: A laterally diffused metal-oxide-semiconductor transistor device includes a substrate having a first conductivity type with a semiconductor layer formed over the substrate. A source region and a drain extension region of the first conductivity type are formed in the semiconductor layer. A body region of a second conductivity type is formed in the semiconductor layer. A conductive gate is formed over a gate dielectric layer that is formed over a channel region. A drain contact electrically connects the drain extension region to the substrate and is laterally spaced from the channel region. The drain contact includes a highly-doped drain contact region formed between the substrate and the drain extension region in the semiconductor layer, wherein a topmost portion of the highly-doped drain contact region is spaced from the upper surface of the semiconductor layer. A source contact electrically connects the source region to the body region.

Abstract: A LDMOS transistor comprises a trench formed through the epitaxial layer at least to the top surface of the substrate, the trench having a bottom surface and a sidewall contacting the source region and the portion of the channel region extending under the source region. A first insulating layer is formed over the upper surface and sidewall surfaces of the conductive gate. A continuous layer of conductive material forming a source contact and a gate shield electrode is formed along the bottom surface and the sidewall of the trench and over the first insulating layer to cover the top and sidewall surfaces of the conductive gate. A second insulating layer is formed over an active area of the transistor, including over the continuous layer of conductive material and filling the trench. A drain electrode can extend over the second insulating layer to substantially cover the active area.

Abstract: A semiconductor device includes a semiconductor substrate, a first p-channel laterally diffused metal oxide semiconductor (LDMOS) transistor formed over the semiconductor substrate and additional p-channel LDMOS transistors formed over the semiconductor substrate. First drain and gate electrodes are formed over the substrate and are coupled to the first LDMOS transistor. Additional drain and gate electrodes are formed over the substrate and are coupled to the second LDMOS transistor. A common source electrode for the first and second LDMOS transistors is also formed over the substrate.

Abstract: A method of fabricating a capacitor in a semiconductor substrate. The semiconductor substrate is doped to have a low resistivity. A second electrode, insulated from a first electrode, is formed over a front side surface and connected by a metal-filled via to the back side surface. The via may be omitted and the second electrode may be in electrical contact with the substrate or may be formed on top of the dielectric layer, yielding a pair of series-connected capacitors. ESD protection for the capacitor is provided by a pair of oppositely-directed diodes formed in the substrate connected in parallel with the capacitor. Capacitance is increased while maintaining a low effective series resistance. Electrodes include a plurality of fingers, which are interdigitated with the fingers of other electrode. The capacitor is fabricated in a wafer-scale process with other capacitors, where capacitors are separated from each other by a dicing technique.

Abstract: In a trench-gated MIS device contact is made to the gate within the trench, thereby eliminating the need to have the gate material, typically polysilicon, extend outside of the trench. This avoids the problem of stress at the upper corners of the trench. Contact between the gate metal and the polysilicon is normally made in a gate metal region that is outside the active region of the device. Various configurations for making the contact between the gate metal and the polysilicon are described, including embodiments wherein the trench is widened in the area of contact. Since the polysilicon is etched back below the top surface of the silicon throughout the device, there is normally no need for a polysilicon mask, thereby saving fabrication costs.

Abstract: An LDMOS device comprises a substrate having a first conductivity type and a lightly doped epitaxial layer thereon having an upper surface. Source and drain regions of the first conductivity type are formed in the epitaxial layer along with a channel region of a second conductivity type formed therebetween. A conductive gate is formed over a gate dielectric layer. A drain contact electrically connects the drain region to the substrate, comprising a first trench formed from the upper surface of the epitaxial layer to the substrate and having a side wall along the epitaxial layer, a highly doped region of the first conductivity type formed along the side wall of the first trench, and a drain plug in the first trench adjacent the highly doped region. A source contact is provided and an insulating layer is formed between the conductive gate and the source contact.

Abstract: A low voltage power device includes a plurality of quasi-vertical LDMOS device cells. A conductive trench sinker is formed through the epitaxial layer and adjacent a selected one of the source and drain regions in each cell. The trench sinker electrically couples the selected one of the source and drain regions to the substrate for coupling current from the channel to the substrate. The resulting device exhibits a vertical current flow between the metal electrode covering the front surface and the second electrode formed at the back side of the wafer. The device cells are arranged in a closed cell configuration.

Abstract: A laterally diffused metal-oxide-semiconductor (LDMOS) transistor device includes a doped substrate having an epitaxial layer thereover having source and drain implant regions and body and lightly doped drain regions formed therein. The channel region and lightly doped drain regions are doped to a depth to abut the top surface of the substrate. In alternative embodiments, a buffer region of the second conductivity type and having dopant concentration greater than or equal to about the channel region is formed over the top surface of the substrate between the top surface of the substrate and the channel region and lightly doped drain region, wherein the channel region and lightly doped drain regions are doped to a depth to abut the buffer region.

Abstract: A laterally diffused metal-oxide-semiconductor transistor device includes a substrate having a first conductivity type with a semiconductor layer formed over the substrate. A source region and a drain extension region of the first conductivity type are formed in the semiconductor layer. A body region of a second conductivity type is formed in the semiconductor layer. A conductive gate is formed over a gate dielectric layer that is formed over a channel region. A drain contact electrically connects the drain extension region to the substrate and is laterally spaced from the channel region. The drain contact includes a highly-doped drain contact region formed between the substrate and the drain extension region in the semiconductor layer, wherein a topmost portion of the highly-doped drain contact region is spaced from the upper surface of the semiconductor layer. A source contact electrically connects the source region to the body region.

Abstract: A semiconductor device includes at least one macro-cell device, the macro-cell device comprising a plurality of LDMOS devices. A first conductive layer is formed over the substrate, the first conductive layer providing source and drain contacts for the macro-cell device. A first isolation layer is formed over the first conductive layer and a second conductive layer is formed over the first isolation layer, the second conductive layer forming a drain bus and a source bus, wherein the buses are electrically coupled to the contacts through the first isolation layer. A second isolation layer is formed over the second conductive layer and insulates the source bus from the drain bus. A plurality of conductive bumps are formed over the second isolation layer, at least one of the conductive bumps directly contacting the drain bus and at least one of the conductive bumps directly contacting the source bus through the second isolation layer.

Abstract: A Schottky rectifier includes a rectifying interface between a semiconductor body and a metal layer. Trenches are formed in the surface of the semiconductor body and regions of a conductivity type opposite to the conductivity type of the body are formed along the sidewalls and bottoms of the trenches, the regions forming PN junctions with the rest of the body. When the rectifier is reverse-biased, the depletion regions along the PN junctions merge to occupy the entire width of the mesas. The device is fabricated by implanting dopant directly through the sidewalls and bottoms of the trenches, by filling the trenches with a material containing dopant and causing the dopant to diffuse through the sidewalls and bottoms of the trenches, or by implanting and diffusing the dopant into a gate filling material.

Abstract: A laterally diffused metal-oxide-semiconductor (LDMOS) transistor device includes a doped substrate having an epitaxial layer thereover having source and drain implant regions and body and lightly doped drain regions formed therein. The channel region and lightly doped drain regions are doped to a depth to abut the top surface of the substrate. In alternative embodiments, a buffer region of the second conductivity type and having dopant concentration greater than or equal to about the channel region is formed over the top surface of the substrate between the top surface of the substrate and the channel region and lightly doped drain region, wherein the channel region and lightly doped drain regions are doped to a depth to abut the buffer region.

Abstract: A LDMOS transistor comprises a trench formed through the epitaxial layer at least to the top surface of the substrate, the trench having a bottom surface and a sidewall contacting the source region and the portion of the channel region extending under the source region. A first insulating layer is formed over the upper surface and sidewall surfaces of the conductive gate. A continuous layer of conductive material forming a source contact and a gate shield electrode is formed along the bottom surface and the sidewall of the trench and over the first insulating layer to cover the top and sidewall surfaces of the conductive gate. A second insulating layer is formed over an active area of the transistor, including over the continuous layer of conductive material and filling the trench. A drain electrode can extend over the second insulating layer to substantially cover the active area.

Abstract: An LDMOS device comprises a substrate having a first conductivity type and a lightly doped epitaxial layer thereon having an upper surface. Source and drain regions of the first conductivity type are formed in the epitaxial layer along with a channel region of a second conductivity type formed therebetween. A conductive gate is formed over a gate dielectric layer. A drain contact electrically connects the drain region to the substrate, comprising a first trench formed from the upper surface of the epitaxial layer to the substrate and having a side wall along the epitaxial layer, a highly doped region of the first conductivity type formed along the side wall of the first trench, and a drain plug in the first trench adjacent the highly doped region. A source contact is provided and an insulating layer is formed between the conductive gate and the source contact.

Abstract: A precision high-frequency capacitor includes a dielectric layer formed on the front side surface of a semiconductor substrate and a first electrode on top of the dielectric layer. The semiconductor substrate is heavily doped and therefore has a low resistivity. A second electrode, insulated from the first electrode, is also formed over the front side surface. In one embodiment, the second electrode is connected by a metal-filled via to a layer of conductive material on the back side of the substrate. In alternative embodiments, the via is omitted and the second electrode is either in electrical contact with the substrate or is formed on top of the dielectric layer, yielding a pair of series-connected capacitors. ESD protection for the capacitor can be provided by a pair of oppositely-directed diodes formed in the substrate and connected in parallel with the capacitor.

Abstract: In a trench-gated MIS device contact is made to the gate within the trench, thereby eliminating the need to have the gate material, typically polysilicon, extend outside of the trench. This avoids the problem of stress at the upper corners of the trench. Contact between the gate metal and the polysilicon is normally made in a gate metal region that is outside the active region of the device. Various configurations for making the contact between the gate metal and the polysilicon are described, including embodiments wherein the trench is widened in the area of contact. Since the polysilicon is etched back below the top surface of the silicon throughout the device, there is normally no need for a polysilicon mask, thereby saving fabrication costs.

Abstract: In one embodiment of the present invention, a method for fabricating semiconductor devices comprises forming an active region about a front-side of a substrate. A plurality of trenches are then formed about a back-side of the substrate. A grid of banks separates the trenches. A conductive material is then applied to the back-side of the substrate. The trenches and the conductive material act to reduce the on-state resistance of the substrate and enhance thermal conductivity, while the grid of banks maintains the structural strength of the wafer.

Abstract: In a trench-gated MIS device contact is made to the gate within the trench, thereby eliminating the need to have the gate material, typically polysilicon, extend outside of the trench. This avoids the problem of stress at the upper corners of the trench. Contact between the gate metal and the polysilicon is normally made in a gate metal region that is outside the active region of the device. Various configurations for making the contact between the gate metal and the polysilicon are described, including embodiments wherein the trench is widened in the area of contact. Since the polysilicon is etched back below the top surface of the silicon throughout the device, there is normally no need for a polysilicon mask, thereby saving fabrication costs.

Abstract: In a trench-gated MIS device contact is made to the gate within the trench, thereby eliminating the need to have the gate material, typically polysilicon, extend outside of the trench. This avoids the problem of stress at the upper corners of the trench. Contact between the gate metal and the polysilicon is normally made in a gate metal region that is outside the active region of the device. Various configurations for making the contact between the gate metal and the polysilicon are described, including embodiments wherein the trench is widened in the area of contact. Since the polysilicon is etched back below the top surface of the silicon throughout the device, there is normally no need for a polysilicon mask, thereby saving fabrication costs.