Abstract: A process for forming at least two different doping levels at the surface of a wafer using one photo resist pattern and implantation process step. A resist layer is developed (but not baked) to form a first resist geometry and a plurality of sublithographic resist geometries. The resist layer is baked causing the sublithographic resist geometries to reflow into a continuous second resist geometry having a thickness less that the first resist geometry. A high energy implant implants dopants through the second resist geometry but not through the first resist geometry. A low energy implant is blocked by both the first and second resist geometries.

Abstract: The density of a transistor array is increased by forming one or more deep trench isolation structures in a semiconductor material. The deep trench isolation structures laterally surround the transistors in the array. The deep trench isolation structures limit the lateral diffusion of dopants and the lateral movement of charge carriers.

Abstract: An integrated circuit which includes a field-plated FET is formed by forming a first opening in a layer of oxide mask, exposing an area for a drift region. Dopants are implanted into the substrate under the first opening. Subsequently, dielectric sidewalls are formed along a lateral boundary of the first opening. A field relief oxide is formed by thermal oxidation in the area of the first opening exposed by the dielectric sidewalls. The implanted dopants are diffused into the substrate to form the drift region, extending laterally past the layer of field relief oxide. The dielectric sidewalls and layer of oxide mask are removed after the layer of field relief oxide is formed. A gate is formed over a body of the field-plated FET and over the adjacent drift region. A field plate is formed immediately over the field relief oxide adjacent to the gate.

Abstract: A semiconductor device is formed by forming a deep trench in a substrate and a dielectric liner on sidewalls of the deep trench. A first undoped polysilicon layer is formed on the semiconductor device, extending into the deep trench on the dielectric liner, but not filling the deep trench. Dopants are implanted into the first polysilicon layer. A second layer of polysilicon is formed on the first layer of polysilicon. A thermal drive anneal activates and diffuses the dopants. In one version, the dielectric liner is removed at the bottom of the deep trench before the first polysilicon layer is formed, so that the polysilicon in the deep trench provides a contact to the substrate. In another version, the polysilicon in the deep trench is isolated from the substrate by the dielectric liner.

Abstract: A semiconductor device has an n-type buried layer formed by implanting antimony and/or arsenic into the p-type first epitaxial layer at a high dose and low energy, and implanting phosphorus at a low dose and high energy. A thermal drive process diffuses and activates both the heavy dopants and the phosphorus. The antimony and arsenic do not diffuse significantly, maintaining a narrow profile for a main layer of the buried layer. The phosphorus diffuses to provide a lightly-doped layer several microns thick below the main layer. An epitaxial p-type layer is grown over the buried layer.

Abstract: A semiconductor device is formed by forming a deep trench in a substrate and a dielectric liner on sidewalls of the deep trench. A first undoped polysilicon layer is formed on the semiconductor device, extending into the deep trench on the dielectric liner, but not filling the deep trench. Dopants are implanted into the first polysilicon layer. A second layer of polysilicon is formed on the first layer of polysilicon. A thermal drive anneal activates and diffuses the dopants. In one version, the dielectric liner is removed at the bottom of the deep trench before the first polysilicon layer is formed, so that the polysilicon in the deep trench provides a contact to the substrate. In another version, the polysilicon in the deep trench is isolated from the substrate by the dielectric liner.

Abstract: A semiconductor device with a buried layer has a deep trench structure abutting the buried layer and a self-aligned sinker along sidewalls of the deep trench structure. The semiconductor device may be formed by forming a portion of a deep trench down to the buried layer, and implanting dopants into a substrate of the semiconductor device along sidewalls of the deep trench, and subsequently forming a remainder of the deep trench extending below the buried layer. Alternatively, the semiconductor device may be formed by forming the deep trench to extend below the buried layer, and subsequently implanting dopants into the substrate of the semiconductor device along sidewalls of the deep trench.

Abstract: A process for forming at least two different doping levels at the surface of a wafer using one photo resist pattern and implantation process step. A resist layer is developed (but not baked) to form a first resist geometry and a plurality of sublithographic resist geometries. The resist layer is baked causing the sublithographic resist geometries to reflow into a continuous second resist geometry having a thickness less that the first resist geometry. A high energy implant implants dopants through the second resist geometry but not through the first resist geometry. A low energy implant is blocked by both the first and second resist geometries.

Abstract: A semiconductor device is formed by forming a deep trench in a substrate and a dielectric liner on sidewalls of the deep trench. A first undoped polysilicon layer is formed on the semiconductor device, extending into the deep trench on the dielectric liner, but not filling the deep trench. Dopants are implanted into the first polysilicon layer. A second layer of polysilicon is formed on the first layer of polysilicon. A thermal drive anneal activates and diffuses the dopants. In one version, the dielectric liner is removed at the bottom of the deep trench before the first polysilicon layer is formed, so that the polysilicon in the deep trench provides a contact to the substrate. In another version, the polysilicon in the deep trench is isolated from the substrate by the dielectric liner.

Abstract: A semiconductor device has an n-type buried layer formed by implanting antimony and/or arsenic into the p-type first epitaxial layer at a high dose and low energy, and implanting phosphorus at a low dose and high energy. A thermal drive process diffuses and activates both the heavy dopants and the phosphorus. The antimony and arsenic do not diffuse significantly, maintaining a narrow profile for a main layer of the buried layer. The phosphorus diffuses to provide a lightly-doped layer several microns thick below the main layer. An epitaxial p-type layer is grown over the buried layer.

Abstract: A semiconductor device is formed by forming a deep trench in a substrate and a dielectric liner on sidewalls of the deep trench. A first undoped polysilicon layer is formed on the semiconductor device, extending into the deep trench on the dielectric liner, but not filling the deep trench. Dopants are implanted into the first polysilicon layer. A second layer of polysilicon is formed on the first layer of polysilicon. A thermal drive anneal activates and diffuses the dopants. In one version, the dielectric liner is removed at the bottom of the deep trench before the first polysilicon layer is formed, so that the polysilicon in the deep trench provides a contact to the substrate. In another version, the polysilicon in the deep trench is isolated from the substrate by the dielectric liner.

Abstract: A process for forming at least two different doping levels at the surface of a wafer using one photo resist pattern and implantation process step. A resist layer is developed (but not baked) to form a first resist geometry and a plurality of sublithographic resist geometries. The resist layer is baked causing the sublithographic resist geometries to reflow into a continuous second resist geometry having a thickness less that the first resist geometry. A high energy implant implants dopants through the second resist geometry but not through the first resist geometry. A low energy implant is blocked by both the first and second resist geometries.

Abstract: The width of a heavily-doped sinker is substantially reduced by forming the heavily-doped sinker to lie in between a number of closely-spaced trench isolation structures, which have been formed in a semiconductor material. During drive-in, the closely-spaced trench isolation structures significantly limit the lateral diffusion.

Abstract: An ESD cell includes an n+ buried layer (NBL) within a p-epi layer on a substrate. An outer deep trench isolation ring (outer DT ring) includes dielectric sidewalls having a deep n-type diffusion (DEEPN diffusion) ring (DEEPN ring) contacting the dielectric sidewall extending downward to the NBL. The DEEPN ring defines an enclosed p-epi region. A plurality of inner DT structures are within the enclosed p-epi region having dielectric sidewalls and DEEPN diffusions contacting the dielectric sidewalls extending downward from the topside surface to the NBL. The inner DT structures have a sufficiently small spacing with one another so that adjacent DEEPN diffusion regions overlap to form continuous wall of n-type material extending from a first side to a second side of the outer DT ring dividing the enclosed p-epi region into a first and second p-epi region. The first and second p-epi region are connected by the NBL.

Abstract: An integrated circuit containing a first plurality of MOS transistors operating in a low voltage range, and a second plurality of MOS transistors operating in a mid voltage range, may also include a high-voltage MOS transistor which operates in a third voltage range significantly higher than the low and mid voltage ranges, for example 20 to 30 volts. The high-voltage MOS transistor has a closed loop configuration, in which a drain region is surrounded by a gate, which is in turn surrounded by a source region, so that the gate does not overlap field oxide. The integrated circuit may include an n-channel version of the high-voltage MOS transistor and/or a p-channel version of the high-voltage MOS transistor. Implanted regions of the n-channel version and the p-channel version are formed concurrently with implanted regions in the first and second pluralities of MOS transistors.

Abstract: A semiconductor device has an n-type buried layer formed by implanting antimony and/or arsenic into the p-type first epitaxial layer at a high dose and low energy, and implanting phosphorus at a low dose and high energy. A thermal drive process diffuses and activates both the heavy dopants and the phosphorus. The antimony and arsenic do not diffuse significantly, maintaining a narrow profile for a main layer of the buried layer. The phosphorus diffuses to provide a lightly-doped layer several microns thick below the main layer. An epitaxial p-type layer is grown over the buried layer.

Abstract: The density of a transistor array is increased by forming one or more deep trench isolation structures in a semiconductor material. The deep trench isolation structures laterally surround the transistors in the array. The deep trench isolation structures limit the lateral diffusion of dopants and the lateral movement of charge carriers.

Abstract: An integrated circuit containing a first plurality of MOS transistors operating in a low voltage range, and a second plurality of MOS transistors operating in a mid voltage range, may also include a high-voltage MOS transistor which operates in a third voltage range significantly higher than the low and mid voltage ranges, for example 20 to 30 volts. The high-voltage MOS transistor has a closed loop configuration, in which a drain region is surrounded by a gate, which is in turn surrounded by a source region, so that the gate does not overlap field oxide. The integrated circuit may include an n-channel version of the high-voltage MOS transistor and/or a p-channel version of the high-voltage MOS transistor. Implanted regions of the n-channel version and the p-channel version are formed concurrently with implanted regions in the first and second pluralities of MOS transistors.

Abstract: The width of a heavily-doped sinker is substantially reduced by forming the heavily-doped sinker to lie in between a number of closely-spaced trench isolation structures, which have been formed in a semiconductor material. During drive-in, the closely-spaced trench isolation structures significantly limit the lateral diffusion.

Abstract: A junction field-effect transistor (JFET) includes a substrate having a first-type semiconductor surface including a topside surface, and a top gate of a second-type formed in the semiconductor surface. A first-type drain and a first-type source are formed on opposing sides of the top gate. A first deep trench isolation region has an inner first trench wall and an outer first trench wall surrounding the top gate, the drain and the source, and extends vertically to a deep trench depth from the topside surface. A second-type sinker formed in semiconductor surface extends laterally outside the outer first trench wall. The sinker extends vertically from the topside surface to a second-type deep portion which is both below the deep trench depth and laterally inside the inner first trench wall to provide a bottom gate.