A semiconductor device includes a first external electrode with a first electrode surface portion; a second external electrode with a second electrode surface portion; a MOSFET chip with a built-in Zener diode which includes an active region and a peripheral region; a control IC chip which drives the MOSFET chip based on voltage or current between a drain electrode and a source electrode of the MOSFET chip; and a capacitor which supplies power to the MOSFET chip and the control IC chip. The first electrode surface portion is connected to either the drain electrode or the source, the second electrode surface portion is connected to either the source electrode or the drain electrode, a plurality of unit cells of the MOSFET with the built-in Zener diode are provided in the active region, and the breakdown voltage of the Zener diode is set to be lower than that of the peripheral region.

A semiconductor device includes a semiconductor body having first and second opposite sides, a drift region, a body layer at the second side, and a field-stop region in Ohmic connection with the body layer. A source metallization at the second side is in Ohmic connection with the body layer. A drain metallization at the first side is in Ohmic connection with the drift region. A gate electrode at the second side is electrically insulated from the semiconductor body to define an operable switchable channel region in the body layer. A through contact structure extends at least between the first and second sides, and includes a conductive region in Ohmic connection with the gate electrode and a dielectric layer. In a normal projection onto a horizontal plane substantially parallel to the first side, the field-stop region surrounds at least one of the drift region and the gate electrode.

According to one embodiment, a semiconductor device includes first to third electrodes, a conductive member, a semiconductor member, and an insulating member. The conductive member includes a conductive member end portion and a conductive member other-end portion. The conductive member end portion is between the first electrode and the conductive member other-end portion. The conductive member is electrically connected with one of the second electrode or the third electrode. The semiconductor member includes first to third semiconductor regions. The first semiconductor region includes first and second partial regions. The first partial region is between the first and second electrodes. The second semiconductor region is between the first partial region and the third semiconductor region. The third semiconductor region is electrically connected with the second electrode. A portion of the insulating member is between the semiconductor member and the third electrode and between the semiconductor member and the conductive member.

A vertical semiconductor device is formed in a semiconductor layer having a first surface, a second surface and background doping. A first doped region, doped to a conductivity type opposite that of the background, is formed at the second surface of the semiconductor layer. A second doped region of the same conductivity type as the background is formed at the second surface of the semiconductor layer, inside the first doped region. A portion of the semiconductor layer is removed at the first surface, exposing a new third surface. A third doped region is formed inside the semiconductor layer at the third surface. Electrical contact is made at least to the second doped region (via the second surface) and the third doped region (via the new third surface). In this way, vertical DMOS, IGBT, bipolar transistors, thyristors, and other types of devices can be fabricated in thinned semiconductor, or SOI layers.

A method of fabricating a semiconductor device includes forming a buried insulation region within a substrate by processing the substrate using etching and deposition processes. A semiconductor layer is formed over the buried insulation region at a first side of the substrate. Device regions are formed in the semiconductor layer. The substrate is thinned from a second side of the substrate to expose the buried insulation region. The buried insulation region is selectively removed to expose a bottom surface of the substrate. A conductive region is formed under the bottom surface of the substrate.

In one embodiment, a power MOSFET cell includes an N+ silicon substrate having a drain electrode. An N-type drift layer is grown over the substrate. An N-type layer, having a higher dopant concentration than the drift region, is then formed along with a trench having sidewalls. A P-well is formed in the N-type layer, and an N+ source region is formed in the P-well. A gate is formed over the P-well's lateral channel and has a vertical extension into the trench. A positive gate voltage inverts the lateral channel and increases the vertical conduction along the sidewalls to reduce on-resistance. A vertical shield field plate is also located next to the sidewalls and may be connected to the gate. The field plate laterally depletes the N-type layer when the device is off to increase the breakdown voltage. A buried layer and sinker enable the use of a topside drain electrode.

A bidirectional Metal-Oxide-Semiconductor (MOS) device, including a P-type substrate, and an active region. The active region includes a drift region, a first MOS structure and a second MOS structure; the first MOS structure includes a first P-type body region, a first P+ contact region, a first N+ source region, a first metal electrode, and a first gate structure; the second MOS structure includes a second P-type body region, a second P+ contact region, a second N+ source region, a second metal electrode, and a second gate structure; and the drift region includes a dielectric slot, a first N-type layer, a second N-type layer, and an N-type region. The active region is disposed on the upper surface of the P-type substrate. The first MOS structure and the second MOS structure are symmetrically disposed on two ends of the upper layer of the drift region.

A power semiconductor device includes a semiconductor-on-insulator island having a semiconductor region and an insulation structure, the insulation structure being formed by an oxide and separating the semiconductor region from a portion of a semiconductor body of the power semiconductor device. The insulation structure includes a sidewall that laterally confines the semiconductor region; a bottom that vertically confines the semiconductor region; and a local deepening that forms at least a part of a transition between the sidewall and the bottom, wherein the local deepening extends further along the extension direction as compared to the bottom.

Structures and methods for better optimizing the performance of all the circuitry of an SOI IC. Embodiments include SOI IC having dual-thickness active areas, such that digital and non-RF analog circuitry may be fabricated on a relatively thin active layer while RF circuitry may be fabricated on a relatively thick active layer. Fabrication of RF circuitry on the relatively thick active layer allows for improvements to the R.sub.ON*C.sub.OFF figure of merit for the FET devices, and for optimizations not feasible for RF circuitry fabricated on a relatively thin active layer. Two methods of forming shallow-trench isolation (STI) structures in both active layers are described. A first method forms STIs in the thin active layer first, then in the thick active layer. A second method forms STIs in the thin active layer first and partial STIs in the thick active layer, then completes the partial STIs in the thick active layer.