The present application provides a laterally diffused metal oxide semiconductor (LDMOS) transistor and a manufacturing method thereof. The transistor comprising: a semiconductor substrate having a doping region, wherein the doping region comprises a first well region and a second well region with opposite doping types; a source region, a drain region, a shallow trench isolation (STI) structure comprising a laminated structure having an alternate layers of insulating material and ferroelectric material, a gate, a contact hole, and a metal layer. The LDMOS transistor simultaneously increases breakdown voltage (BV) and reduces on-resistance (R.sub.on).

An SOI lateral homogenization field high voltage power semiconductor device, and a manufacturing method and application thereof are provided. The device includes a type I conductive semiconductor substrate, a type II conductive drift region, a type I field clamped layer, type I and type II conductive well regions, the first dielectric oxide layer forming a field oxide layer, the second dielectric oxide layer forming a gate oxide layer, a type II conductive buried dielectric layer, a type II conductive source heavily doped region, a type II conductive drain heavily doped region. The first dielectric oxide layer and the floating field plate polysilicon electrodes form a vertical floating field plate distributed throughout the type II conductive drift region to form a vertical floating equipotential field plate array. When the device is in on-state, high doping concentration can be realized by the full-region depletion effect form the vertical field plate arrays.

A power semiconductor device includes a P-type substrate, an N-type well region, a P-type body region, a gate oxide layer, a polysilicon gate, a first oxide layer, a first N+ contact region, a first P+ contact region, drain metal, a first-type doped region, and a gate oxide layer. An end of the P-type body region is flush with or exceeds an end of the polysilicon gate, wherein C.sub.gd of the power semiconductor device is reduced and a switching frequency of the power semiconductor device is increased. A polysilicon field plate connected with a source is introduced over a drift region that is not only shield an influence of the polysilicon gate on the drift region, thereby eliminating C.sub.gd caused by overlapping of traditional polysilicon gate and drift region, but also enable the power semiconductor device to have strong robustness against an hot carrier effect.

A semiconductor device includes a source region. A drain region has a first conductivity type and a second dopant concentration spaced apart from the source region. A first drift region is located between the source region and the drain region and has the first conductivity type and a first dopant concentration that is lower than the second dopant concentration of the drain region. An oxide structure includes a first portion on or over the first drift region and a tapered portion between the first portion and the drain region. A substrate surface extension is between the tapered portion and the drain region. A buffer region has the first conductivity type between the first drift region and the drain region and under the tapered portion of the oxide structure. The buffer region has a third dopant concentration between the second dopant concentration and the first dopant concentration.

A laterally double-diffused metal oxide semiconductor device is provided, including: a drift region (3) having a first conductivity type; a first body region (10) disposed on the drift region (3) and having a second conductivity type, the first conductivity type and the second conductivity type being opposite conductivity types; a first conductivity type region (13) disposed in the first body region (10); a second body region (12) disposed in the first conductivity type region (13) and having the second conductivity type; a source region (11) disposed in the second body region (12) and having the first conductivity type; and a contact region (9) disposed in the first body region (10) and having the second conductivity type.

A method for manufacturing a semiconductor device includes forming a plate structure over an isolation region. A drain electrode electrically connected to a drift region underlying the isolation region is formed, wherein the drain electrode is separated from a first location of the plate structure by a first distance along a central axis of an active area of the semiconductor device in a direction of a current flow between a source and a drain of the semiconductor device, the drain electrode is separated from a second location of the plate structure by a second distance along a line parallel to the central axis and within the active area. The first distance is less than the second distance.

A semiconductor device includes a semiconductor layer, an element isolation portion that is formed at the semiconductor layer and that defines an element region in the semiconductor layer, and a first contact that is formed in a linear shape along the element isolation portion in a plan view and that is electrically connected to the element isolation portion. The semiconductor device further includes a semiconductor substrate supporting the semiconductor layer and a buried layer formed so as to be contiguous to the semiconductor layer, and the element isolation portion may reach the semiconductor substrate through the buried layer from a front surface of the semiconductor layer.

Existing semiconductor transistor processes may be leveraged to form lateral extensions adjacent to a conventional gate structure. The dielectric thickness under these lateral gate extensions can be varied to tune device performance and enable higher cut-off frequencies without compromising resistance to breakdown at high operating voltages. These extensions may be patterned with dimensions that are not limited by lithographic resolution and overlay capabilities and are compatible with conventional processing for ease of integration with other devices. The lateral extensions and dielectric spacers may be used to form self-aligned source, drain, and channel regions. A narrow-highly-doped channel may be formed under a narrow gate extension to improve operating frequencies. A thick dielectric layer may be formed under a narrow extension gate to improve operation voltage range. The present invention provides an innovative structure with lateral gate extensions which may be referred to as EGMOS (extended gate metal oxide semiconductor).

A semiconductor device includes an insulator layer and a semiconductor layer formed on the insulator layer. The semiconductor layer includes a first region of a first conductivity type, a second region of a second conductivity type, and a lightly doped extension region of the first conductivity type separating the first region and the second region along a lateral x-axis. A dielectric structure laterally surrounds the semiconductor layer. At least one of the first region and the lightly doped extension region is formed at a distance to the dielectric structure along a lateral y-axis orthogonal to the x-axis. Along the x-axis and between the second region and the first region, a lateral extension of the semiconductor layer along the y-axis increases with increasing distance to the second region.

A method for forming a semiconductor device involves providing a semiconductor wafer having an active layer of a first conductivity type. First and second gates having first and second gate polysilicon are formed on the active layer. A first mask region is formed on the active layer. Between the first and second gates, using the first mask region, the first gate polysilicon, and the second gate polysilicon as a mask, a deep well of a second conductivity type, a shallow well of the second conductivity type, a source region of the first conductivity type, and first and second channel regions of the second conductivity type, are formed. In the active layer, using one or more second mask regions, first and second drift regions of the first conductivity type, first and second drain regions of the first conductivity type, and a source connection region of the second conductivity type, are formed.