Abstract:
Breakdown voltage BVdss is enhanced and ON-resistance reduced in RESURF devices, e.g., LDMOS transistors, by careful charge balancing, even when body and drift region charge balance is not ideal, by: (i) providing a plug or sinker near the drain and of the same conductivity type extending through the drift region at least into the underlying body region, and/or (ii) applying bias Viso to a surrounding lateral doped isolation wall coupled to the device buried layer, and/or (iii) providing a variable resistance bridge between the isolation wall and the drift region. The bridge may be a FET whose source-drain couple the isolation wall and drift region and whose gate receives control voltage Vc, or a resistor whose cross-section (X, Y, Z) affects its resistance and pinch-off, to set the percentage of drain voltage coupled to the buried layer via the isolation wall.
Abstract:
Breakdown voltage BVdss is enhanced and ON-resistance reduced in RESURF devices (40, 60, 80, 80′, 80″), e.g., LDMOS transistors, by careful charge balancing, even when body (44, 44′, 84, 84′) and drift (50, 50′, 90, 90′) region charge balance is not ideal, by: (i) providing a plug or sinker (57) near the drain (52, 92) and of the same conductivity type extending through the drift region (50, 50′, 90, 90′) at least into the underlying body region (44, 44′ 84, 84′), and/or (ii) applying bias Viso to a surrounding lateral doped isolation wall (102) coupled to the device buried layer (42, 82), and/or (iii) providing a variable resistance bridge (104) between the isolation wall (102) and the drift region (50, 50′, 90, 90′). The bridge (104) may be a FET (110) whose source-drain (113, 114) couple the isolation wall (102) and drift region (50, 50′, 90, 90′) and whose gate (116) receives control voltage Vc, or a resistor (120) whose cross-section (X, Y, Z) affects its resistance and pinch-off, to set the percentage of drain voltage coupled to the buried layer (42, 82) via the isolation wall (102).
Abstract:
Breakdown voltage BVdss is enhanced and ON-resistance reduced in RESURF devices (40, 60, 80, 80′, 80″), e.g., LDMOS transistors, by careful charge balancing, even when body (44, 44′, 84, 84′) and drift (50, 50′, 90, 90′) region charge balance is not ideal, by: (i) providing a plug or sinker (57) near the drain (52, 92) and of the same conductivity type extending through the drift region (50, 50′, 90, 90′) at least into the underlying body region (44, 44′ 84, 84′), and/or (ii) applying bias Viso to a surrounding lateral doped isolation wall (102) coupled to the device buried layer (42, 82), and/or (iii) providing a variable resistance bridge (104) between the isolation wall (102) and the drift region (50, 50′, 90, 90′). The bridge (104) may be a FET (110) whose source-drain (113, 114) couple the isolation wall (102) and drift region (50, 50′, 90, 90′) and whose gate (116) receives control voltage Vc, or a resistor (120) whose cross-section (X, Y, Z) affects its resistance and pinch-off, to set the percentage of drain voltage coupled to the buried layer (42, 82) via the isolation wall (102).
Abstract:
A method of fabricating a transistor includes forming a field isolation region in a substrate. After forming the field isolation region, dopant is implanted in a first region of a substrate for formation of a drift region. A drain region is formed in a second region of the substrate. The first and second regions laterally overlap to define a conduction path for the transistor. The first region does not extend laterally across the second region.
Abstract:
A method of fabricating a transistor includes forming a field isolation region in a substrate. After forming the field isolation region, dopant is implanted in a first region of a substrate for formation of a drift region. A drain region is formed in a second region of the substrate. The first and second regions laterally overlap to define a conduction path for the transistor. The first region does not extend laterally across the second region.
Abstract:
A device includes a semiconductor substrate, source and drain regions in the semiconductor substrate, a channel region in the semiconductor substrate between the source and drain regions through which charge carriers flow during operation from the source region to the drain region, and a drift region in the semiconductor substrate, on which the drain region is disposed, and through which the charge carriers drift under an electric field arising from application of a bias voltage between the source and drain regions. A PN junction along the drift region includes a first section at the drain region and a second section not at the drain region. The drift region has a lateral profile that varies such that the first section of the PN junction is shallower than the second section of the PN junction.
Abstract:
A device includes a semiconductor substrate, source and drain regions in the semiconductor substrate, a channel region in the semiconductor substrate between the source and drain regions through which charge carriers flow during operation from the source region to the drain region, and a drift region in the semiconductor substrate, on which the drain region is disposed, and through which the charge carriers drift under an electric field arising from application of a bias voltage between the source and drain regions. A PN junction along the drift region includes a first section at the drain region and a second section not at the drain region. The drift region has a lateral profile that varies such that the first section of the PN junction is shallower than the second section of the PN junction.
Abstract:
A semiconductor device includes an isolated p-type well, wherein the isolated p-type well is a first electrode of a capacitor device; a capacitor dielectric on the isolated p-type well; a p-type polysilicon electrode over the capacitor dielectric, wherein the p-type polysilicon electrode is a second electrode of the capacitor device; a first p-type contact region in the isolated p-type well, laterally extending from a first sidewall of the p-type polysilicon electrode; a second p-type contact region in the isolated p-type well, laterally extending from a second sidewall of the p-type polysilicon electrode, opposite the first sidewall of the p-type polysilicon electrode, wherein a portion of the isolated p-type well between the first and second p-type contact regions is under the p-type polysilicon electrode and the capacitor dielectric; and an n-type isolation region surrounding the isolated p-type well. This device may be conveniently coupled to a fringe capacitor.
Abstract:
A semiconductor device includes a source region within a semiconductor substrate, a drain region within the semiconductor substrate, a control gate over the semiconductor substrate and between the source region and the drain region, a first gate between the control gate and the drain region, and a first doped region within the semiconductor region and between the control gate and the first gate. The method of forming the semiconductor device may include depositing an electrode material over the semiconductor substrate, patterning the electrode material to form a control gate and a first gate, implanting a first doped region within the semiconductor substrate between the control gate and the first gate while using the control gate and the first gate as a mask, and implanting a source region within the semiconductor substrate.
Abstract:
Embodiments of microelectronic assemblies are provided. First and second semiconductor devices are formed over a substrate having a first dopant type at a first concentration. First and second buried regions having a second dopant type are formed respectively below the first and second semiconductor devices with a gap therebetween. At least one well region is formed over the substrate and between the first and second semiconductor devices. A barrier region having the first dopant type at a second concentration is formed between and adjacent to the first and second buried regions such that at least a portion of the barrier region extends a depth from the first and second semiconductor devices that is greater or equal to the depth of the buried regions.