Various improvements in vertical transistors, such as IGBTs, are disclosed. The improvements include forming periodic highly-doped p-type emitter dots in the top surface region of a growth substrate, followed by growing the various transistor layers, followed by grounding down the bottom surface of the substrate, followed by a wet etch of the bottom surface to expose the heavily doped p+ layer. A metal contact is then formed over the p+ layer. In another improvement, edge termination structures utilize p-dopants implanted in trenches to create deep p-regions for shaping the electric field, and shallow p-regions between the trenches for rapidly removing holes after turn-off. In another improvement, a dual buffer layer using an n-layer and distributed n+ regions improves breakdown voltage and saturation voltage. In another improvement, p-zones of different concentrations in a termination structure are formed by varying pitches of trenches. In another improvement, beveled saw streets increase breakdown voltage.

A technique of reducing the manufacturing cost of a semiconductor device is provided, There is provided a method of manufacturing a semiconductor device comprising an ion implantation process of implanting at least one of magnesium and beryllium by ion implantation into a first semiconductor layer that is mainly formed from a group III nitride; and a heating process of heating the first semiconductor layer in an atmosphere that includes an anneal gas of at least one of magnesium and beryllium, after the ion implantation process.

There is provided a semiconductor device having LDMOS transistors embedded in a semiconductor substrate to boost source-drain breakdown voltage, with arrangements to prevent fluctuations of element characteristics caused by electric field concentration so that the reliability of the semiconductor device is improved. A trench is formed over the upper surface of a separation insulating film of each LDMOS transistor, the trench having a gate electrode partially embedded therein. This structure prevents electric field concentration in the semiconductor substrate near the source-side edge of the separation insulating film.

A lateral superjunction MOSFET device includes multiple transistor cells connected to a lateral superjunction structure, each transistor cell including a conductive gate finger, a source region finger, a body contact region finger and a drain region finger arranged laterally within each transistor cell. Each of the drain region fingers, the source region fingers and the body contact region fingers is a doped region finger having a termination region at an end of the doped region finger. The lateral superjunction MOSFET device further includes a termination structure formed in the termination region of each doped region finger and including one or more termination columns having the same conductivity type as the doped region finger and positioned near the end of the doped region finger. The one or more termination columns extend through the lateral superjunction structure and are electrically unbiased.

The performance of a semiconductor device is improved. An emitter electrode is coupled to a P-type body region and an N.sup.+-type emitter region of a linear active cell region via a contact groove formed on an interlayer insulating film and is coupled to a P-type body region of a linear hole connector cell region via a contact groove. The contact grooves arranged in the linear hole connector cell region are shorter than the contact groove in plan view.

In one embodiment, a power MOSFET vertically conducts current. A bottom electrode may be connected to a positive voltage, and a top electrode may be connected to a low voltage, such as a load connected to ground. A gate and/or a field plate, such as polysilicon, is within a trench. The trench has a tapered oxide layer insulating the polysilicon from the silicon walls. The oxide is much thicker near the bottom of the trench than near the top to increase the breakdown voltage. The tapered oxide is formed by implanting nitrogen into the trench walls to form a tapered nitrogen dopant concentration. This forms a tapered silicon nitride layer after an anneal. The tapered silicon nitride variably inhibits oxide growth in a subsequent oxidation step.

An electrical device that in some embodiments includes a substrate including a lateral device region and a vertical device region. A lateral diffusion metal oxide semiconductor (LDMOS) device may be present in the lateral device region, wherein a drift region of the LDMOS device has a length that is parallel to an upper surface of the substrate in which the LDMOS device is formed. A vertical field effect transistor (VFET) device may be present in the vertical device region, wherein a vertical channel of the VFET has a length that is perpendicular to said upper surface of the substrate, the VFET including a gate structure that is positioned around the vertical channel.

A memory array includes a plurality of memory pages, each memory page includes a plurality of memory bytes, each memory byte includes a plurality of memory cells, and each memory cell includes a floating gate module, a control element, and an erase element. Memory bytes of the same column are coupled to the same erase line, and memory bytes of different columns are coupled to different erase lines. Therefore, the memory array is able to support byte operations while the memory cells of the same memory byte can share the same wells. The circuit area of the memory array can be reduced and the operation of the memory array can be more flexible.

A trench IGBT includes a floating P well and a floating N+ well that extends down into the floating P well. A bottom surface of the floating P well has a novel waved contour so that it has thinner portions and thicker portions. When the IGBT is on, electrons flow from an N+ emitter, vertically through a channel along a trench sidewall, and to an N type drift layer. Additional electrons flow through the channel but then pass under the trench, through the floating P well to the floating N+ well, and laterally through the floating N+ well. NPN transistors are located at thinner portions of the floating P type well. The NPN transistors inject electrons from the floating N+ type well down into the N drift layer. The extra electron injection reduces V.sub.CE(SAT). The waved contour can be made without adding any masking step to an IGBT manufacturing process.

An integrated circuit device includes at least two epitaxially grown active regions grown onto a substrate, the active regions being placed between a first gate device and a second gate device. The integrated circuit device includes at least one dummy gate between the two epitaxially grown active regions and between the first gate device and the second gate device, wherein each active region is substantially uniform in length. The first gate device and the second device are formed over a first well having a first conductivity type and the dummy gate is formed over a second well having a second conductivity type.