A cost effective process flow for manufacturing semiconductor on insulator structures is parallel is provided. Each of the multiple semiconductor-on-insulator composite structures prepared in parallel comprises a charge trapping layer (CTL).

A lateral trench MOSFET comprises an insulating layer buried in a substrate, a body region in the substrate, an isolation region in the substrate, a first drain/source region over the body region, a second drain/source region in the substrate, wherein the first drain/source region and the second drain/source region are on opposing sides of the isolation region, a drift region comprising a first drift region of a first doping density formed between the second drain/source region and the insulating layer, wherein the first drift region comprises an upper portion surrounded by isolation regions and a lower portion and a second drift region of a second doping density formed between the isolation region and the insulating layer, wherein a height of the second drift region is equal to a height of the lower portion of the first drift region.

A cost effective process flow for manufacturing semiconductor on insulator structures is parallel is provided. Each of the multiple semiconductor-on-insulator composite structures prepared in parallel includes a charge trapping layer (CTL).

A first side wall and a second side wall of a trench are each an a-plane having high carrier mobility. Along the first side wall of the trench, a gate insulating film is provided. A gate electrode is provided in the trench, and across the gate insulating film, opposes a portion of a p-type base region between an n.sup.+-type source region and an n-type current spreading region. Along the second side wall of the trench, a conductive layer is provided. The conductive layer, at the second side wall of the trench, forms Schottky contacts with a p.sup.++-type contact region, the p-type base region, and the n-type current spreading region. The trench has a bottom corner portion that is at the second side wall and encompassed by a p.sup.+-type region that is provided in the n-type current spreading region so as to be separated from the p-type base region.

A vertical MOSFET having a trench gate structure includes an n.sup.-type drift layer and a p-type base layer formed by epitaxial growth. In the n.sup.-type drift layer, an n-type region, a first p.sup.+-type region, and a second p.sup.+-type region are provided. A metal film of a trench SBD is connected to a source electrode; and a p.sup.+-type region is provided between the source electrode and the p-type base layer.

A semiconductor device includes a substrate, a semiconductor body and a metal layer between the substrate and the semiconductor body. The device further includes first and second electrodes, a first control electrode between the semiconductor body and the first electrode; and a second control electrode between the semiconductor body and the second electrode. The semiconductor body includes a first to fifth semiconductor layers. The second semiconductor layer is provided between the first semiconductor layer and the first electrode. The third semiconductor layer is selectively provided between the second semiconductor layer and the first electrode. The fourth semiconductor layer is provided between the first semiconductor layer and the second electrode. The fifth semiconductor layer selectively provided between the fourth semiconductor layer and the second electrode. The first, third and fifth semiconductor layers are of a first conductivity type. The second and fourth semiconductor layers are of a second conductivity type.

A lateral trench MOSFET comprises an insulating layer buried in a substrate, a body region in the substrate, an isolation region in the substrate, a first drain/source region over the body region, a second drain/source region in the substrate, wherein the first drain/source region and the second drain/source region are on opposing sides of the isolation region, a drift region comprising a first drift region of a first doping density formed between the second drain/source region and the insulating layer, wherein the first drift region comprises an upper portion surrounded by isolation regions and a lower portion and a second drift region of a second doping density formed between the isolation region and the insulating layer, wherein a height of the second drift region is equal to a height of the lower portion of the first drift region.

A vertical semiconductor device (e.g. a vertical power device, an IGBT device, a vertical bipolar transistor, a UMOS device or a GTO thyristor) is formed with an active semiconductor region, within which a plurality of semiconductor structures have been fabricated to form an active device, and below which at least a portion of a substrate material has been removed to isolate the active device, to expose at least one of the semiconductor structures for bottom side electrical connection and to enhance thermal dissipation. At least one of the semiconductor structures is preferably contacted by an electrode at the bottom side of the active semiconductor region.

A vertical semiconductor device (e.g. a vertical power device, an IGBT device, a vertical bipolar transistor, a UMOS device or a GTO thyristor) is formed with an active semiconductor region, within which a plurality of semiconductor structures have been fabricated to form an active device, and below which at least a portion of a substrate material has been removed to isolate the active device, to expose at least one of the semiconductor structures for bottom side electrical connection and to enhance thermal dissipation. At least one of the semiconductor structures is preferably contacted by an electrode at the bottom side of the active semiconductor region.

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.