Integrated circuits with improved laterally diffused metal oxide semiconductor (LDMOS) structures, and methods of fabricating the same, are provided. An exemplary LDMOS integrated circuit includes a p-type semiconductor substrate, an n-type epitaxial layer disposed over and in contact with the p-type semiconductor substrate, and a p-type implant layer disposed within the n-type epitaxial layer, wherein the p-type implant layer is not in contact with the p-type semiconductor substrate. It further includes an n-type reduced surface field region disposed over and in contact with the p-type implant layer, a p-type body well disposed on a lateral side of the p-type implant layer and the n-type reduced surface field region, and a shallow trench isolation (STI) structure disposed within the n-type reduced surface field region. Still further, it includes a gate structure disposed partially over the p-type body well, partially over the n-type surface field region, and partially over the STI structure.

LDMOS devices are disclosed. An LDMOS device includes at least one drift region disposed in a portion of a semiconductor substrate; at least one isolation structure at a surface of the semiconductor substrate; a D-well region positioned adjacent a portion of the at least one drift region, and an intersection of the drift region and the D-well region forming a junction between first and second conductivity types; a gate structure disposed over the semiconductor substrate; a source contact region disposed on the surface of the D-well region; a drain contact region disposed adjacent the isolation structure; and a double buffer region comprising a first buried layer lying beneath the D-well region and the drift region and doped to the second conductivity type and a second high voltage deep diffusion layer lying beneath the first buried layer and doped to the first conductivity type. Methods are disclosed.

A dual-well metal oxide semiconductor (MOS) device includes: a semiconductor substrate, an active layer, a first conductive type well, a first conductive type body region, a second conductive type well, a gate, a second conductive type lightly doped diffusion (LDD) region, a second conductive type source, a second conductive type connection region, and a second conductive type drain. The second conductive type well is connected to the first conductive type well in a lateral direction, and a PN junction is formed therebetween right below the gate. The second conductive type connection region is formed right below a spacer of the gate, and is connected to the second conductive type source in a lateral direction to avoid OFF-channel. The second conductive type connection region is formed by a tilt-angle ion implantation process step through the spacer.

A semiconductor structure and a method for forming the same are provided. The semiconductor structure comprises a first doped region, a second doped region, a doped strip and a top doped region. The first doped region has a first type conductivity. The second doped region is formed in the first doped region and has a second type conductivity opposite to the first type conductivity. The doped strip is formed in the first doped region and has the second type conductivity. The top doped region is formed in the doped strip and has the first type conductivity. The top doped region has a first sidewall and a second sidewall opposite to the first sidewall. The doped strip is extended beyond the first sidewall or the second sidewall.

A MOSFET transistor in a SiGe BICMOS technology and resulting structure having a drain-gate feedback capacitance shield formed between a gate electrode and the drain region. The shield does not overlap the gate and thereby minimizes effect on the input capacitance of the transistor. The process does not require complex or costly processing since the shield is composed of bipolar base material commonly used in SiGe BICMOS technologies.

A method of fabricating a MOSFET transistor in a SiGe BICMOS technology and resulting structure having a drain-gate feedback capacitance shield formed between a gate electrode and the drain region. The shield does not overlap the gate and thereby minimizes effect on the input capacitance of the transistor. The process does not require complex or costly processing since the shield is composed of bipolar base material commonly used in SiGe BICMOS technologies.

The present disclosure relates to a lateral double-diffused metal oxide semiconductor transistor and a method for manufacturing the same. In the method, a high-voltage gate dielectric is formed at a surface of a semiconductor layer. A thin gate dielectric is formed above the substrate and has at least a portion adjacent to the high-voltage gate dielectric. A gate conductor is formed above the thin gate dielectric and the high-voltage gate dielectric. A first mask is used for patterning the gate conductor to define a first sidewall of the gate conductor above the thin gate dielectric. A second mask is used for patterning the gate conductor to define a second sidewall of the gate conductor at least partially above the high-voltage gate dielectric. Source and drain regions are formed to have a first doping type. The method further comprises doping through the first mask to form a body region of a second doping type. The second doping type is opposite to the first doping type. The method simplifies a manufacturer process and improves reliability of the resultant devices.

A semiconductor device includes a substrate having a first conductivity type, a high-voltage well having a second conductivity type and disposed in the substrate, a high-voltage doped region having the first conductivity type and disposed in the high-voltage well, a drain region disposed in the high-voltage well and spaced apart from the high-voltage doped region, a source region disposed in the high-voltage doped region, a first gate structure disposed above a first side portion of the high-voltage doped region between the source region and the drain region, and a second gate structure disposed above a second and opposite side portion of the high-voltage doped region.

A semiconductor device includes a semiconductor substrate having a first conductivity type, an epitaxial layer having a second conductivity type, an isolation area in the epitaxial layer to define an active area of the semiconductor substrate, a body area having a first conductivity type and a drift area having a second conductivity type adjacent to each other in the epitaxial layer, a LOCOS insulating layer in the drift area and surrounded by the drift area, a drain area adjacent to a side part of the LOCOS insulating layer and surrounded by the drift area, a body contact area and a source area in the body area and surrounded by the body area, and a gate area overlapping the drift area and a part of the LOCOS insulating layer from a direction of the body area.

An N-type Lateral Diffused Metal-Oxide-Semiconductor (NLDMOS) transistor is provided. The NLDMOS transistor comprises a P-type substrate; and a semiconductor layer having a deep N-type well region formed on the P-type substrate. Further, the NLDMOS transistor also includes at least a P-type body region and an N-type drift region formed in the deep N-type well region; and an N-type heavily doped drain region formed in the N-type drift region. Further, the NLDMOS transistor includes a P-type doped reverse type region formed below the N-type drift region in the deep N-type well region, being physically connected with the first P-type body region, and preventing carriers from escaping between the N-type source region and external devices.