Integrated circuits including LDMOS transistor structures and methods for fabricating LDMOS transistor structures are provided. An exemplary method for fabricating an LDMOS transistor structure includes providing a semiconductor-on-insulator (SOI) substrate including a semiconductor layer overlying an insulator layer overlying a bulk layer. The method includes forming a gate structure overlying the substrate. A channel region is formed in the semiconductor layer under the gate structure. The method includes forming a source region overlying the substrate. Further, the method includes forming a drain region overlying the substrate. A drift region is located between the drain region and the gate structure. Also, the method includes forming contacts to the gate structure, the source region, and the drain region.

A semiconductor device includes a lateral transistor having: a semiconductor substrate including a drift layer; a first impurity layer in the drift layer; a channel layer in the drift layer; a second impurity layer in the channel layer; a separation insulation film on the drift layer between the channel layer and the first impurity layer; a gate insulation film on a channel region between the second impurity layer and the drift layer connected with the separation insulation film; a gate electrode on the gate insulation film and the separation insulation film; a first electrode connected with the first impurity layer; a second electrode connected with the second impurity layer and the channel layer; and a field plate on the separation insulation film between the gate electrode and the first electrode and connected with the first electrode. The field plate is larger than the gate electrode in a current direction.

A transistor structure including a substrate, a gate, a first dielectric layer, a first contact and a second contact is provided. The gate is disposed on the substrate. The first dielectric layer is disposed on the substrate. The first dielectric layer covers a portion of a top surface of the gate. The first contact is electrically connected to the gate. The second contact is disposed on the first dielectric layer. The second contact is electrically connected with the first contact.

A semiconductor device comprises a transistor formed in a semiconductor body having a first main surface. The transistor comprises a source region, a drain region, a channel region, a drift zone, a source contact electrically connected to the source region, a drain contact electrically connected to the drain region, and a gate electrode at the channel region. The channel region and the drift zone are disposed along a first direction between the source region and the drain region, the first direction being parallel to the first main surface. The channel region has a shape of a first ridge extending along the first direction. One of the source contact and the drain contact is adjacent to the first main surface, the other one of the source contact and the drain contact is adjacent to a second main surface that is opposite to the first main surface.

A metal-oxide-semiconductor field-effect transistor (MOSFET) power device includes an active region formed on a bulk semiconductor substrate, the active region having a first conductivity type formed on at least a portion of the bulk semiconductor substrate. A first terminal is formed on an upper surface of the structure and electrically connects with at least one other region having the first conductivity type formed in the active region. A buried well having a second conductivity type is formed in the active region and is coupled with a second terminal formed on the upper surface of the structure. The buried well and the active region form a clamping diode which positions a breakdown avalanche region between the buried well and the first terminal. A breakdown voltage of at least one of the power devices is a function of characteristics of the buried well.

An LDMOS device includes a handle portion having a buried dielectric layer and a semiconductor layer thereon doped a second dopant type. A drift region doped a first type is within the semiconductor layer providing a drain extension. A gate stack includes a gate electrode on a gate dielectric layer on respective sides of a junction with the drift region. A DWELL region is within the semiconductor layer. A source region doped the first type is within the DWELL region. A drain region doped the first type is within the drift region. A first partial buried layer doped the second type is in a first portion of the drift region including under the gate electrode. A second partial buried layer doped the first type is in a second portion of the drift region including under the drain.

A device includes a semiconductor substrate having a first conductivity type, a device isolating region in the semiconductor substrate, defining an active area, and having a second conductivity type, a body region in the active area and having the first conductivity type, and a drain region in the active area and spaced from the body region to define a conduction path of the device, the drain region having the second conductivity type. At least one of the body region and the device isolating region includes a plurality of peripheral, constituent regions disposed along a lateral periphery of the active area, each peripheral, constituent region defining a non-uniform spacing between the device isolating region and the body region. The non-uniform spacing at a respective peripheral region of the plurality of peripheral, constituent regions establishes a first breakdown voltage lower than a second breakdown voltage in the conduction path.

The present disclosure provides a method for forming a semiconductor device, including: forming a mask layer over a substrate, the mask layer containing an opening, exposing a surface portion of the substrate to form an exposed surface portion of the substrate; forming an insulation structure between the mask layer and the substrate, and in the opening; performing a thinning process on the insulation structure exposed by the opening to form a recess region on a top of the insulation structure; and forming a gate electrode over the insulation structure and covering a portion of the recess region.

Disclosed are methods that employ a mask with openings arranged in a pattern of elongated trenches and holes of varying widths to achieve a linearly graded conductivity level. These methods can be used to form a lateral double-diffused metal oxide semiconductor field effect transistor (LDMOSFET) with a drain drift region having an appropriate type conductivity at a level that increases essentially linearly from the body region to the drain region. Furthermore, these methods also provide for improve manufacturability in that multiple instances of this same pattern can be used during a single dopant implant process to implant a first dopant with a first type (e.g., N-type) conductivity into the drain drift regions of both first and second type LDMOSFETs (e.g., N and P-type LDMOSFETs, respectively). In this case, the drain drift region of a second type LDMOSFET can subsequently be uniformly counter-doped. Also disclosed are the resulting semiconductor structures.

A semiconductor device includes a supporting substrate, an insulating film formed in a first region over the supporting substrate, a first semiconductor layer formed over the insulating film, a first epitaxial layer formed in an opening of the insulating film in a second region over the supporting substrate, an element isolation region formed between the first semiconductor layer and the first epitaxial layer, and a semiconductor element formed over each of the first semiconductor layer in the first region and the first epitaxial layer in the second region. The first semiconductor layer and the first epitaxial layer is spaced apart from each other by 5 μm or more.