A vertical JFET with a ladder termination may be made by a method using a limited number of masks. A first mask is used to form mesas and trenches in active cell and termination regions simultaneously. A mask-less self-aligned process is used to form silicide source and gate contacts. A second mask is used to open windows to the contacts. A third mask is used to pattern overlay metallization. An optional fourth mask is used to pattern passivation. Optionally the channel may be doped via angled implantation, and the width of the trenches and mesas in the active cell region may be varied from those in the termination region.

A semiconductor device of the present invention includes a semiconductor layer of a first conductivity type having a cell portion and an outer peripheral portion disposed around the cell portion, formed with a gate trench at a surface side of the cell portion, and a gate electrode buried in the gate trench via a gate insulating film, forming a channel at a portion lateral to the gate trench at ON-time, the outer peripheral portion has a semiconductor surface disposed at a depth position equal to or deeper than a depth of the gate trench, and the semiconductor device further includes a voltage resistant structure having a semiconductor region of a second conductivity type formed in the semiconductor surface of the outer peripheral portion.

The semiconductor device of the present invention includes a first conductivity type semiconductor layer made of a wide bandgap semiconductor and a Schottky electrode formed to come into contact with a surface of the semiconductor layer, and has a threshold voltage V.sub.th of 0.3 V to 0.7 V and a leakage current J.sub.r of 110.sup.9 A/cm.sup.2 to 110.sup.4 A/cm.sup.2 in a rated voltage V.sub.R.

A method of making a graphene base transistor with reduced collector area comprising forming an electron injection region, forming an electron collection region, and forming a base region wherein the base region comprises one or more sheets of graphene and wherein the base region is intermediate the electron injection region and the electron collection region and forms electrical interfaces therewith.

A method of manufacturing a wide band gap semiconductor device includes the steps of preparing a wide band gap semiconductor substrate, separating the wide band gap semiconductor substrate into a plurality of first semiconductor chips, fixing the plurality of first semiconductor chips on a fixation member, measuring a breakdown voltage of each of the first semiconductor chips while immersing at least the first semiconductor chips in inert liquid, and after the step of measuring a breakdown voltage of each of the first semiconductor chips, providing a plurality of second semiconductor chips each having each of the first semiconductor chips fixed on the fixation member, by cutting the fixation member.

A method of forming an electrical device that includes forming a gate dielectric layer over a gate electrode, forming source and drain electrodes on opposing sides of the gate electrode, wherein one end of the source and drain electrodes provides a coplanar surface with the gate dielectric, and positioning a 1D or 2D nanoscale material on the coplanar surface to provide the channel region of the electrical device.

A method of forming an electrical device that includes forming a gate dielectric layer over a gate electrode, forming source and drain electrodes on opposing sides of the gate electrode, wherein one end of the source and drain electrodes provides a coplanar surface with the gate dielectric, and positioning a 1D or 2D nanoscale material on the coplanar surface to provide the channel region of the electrical device.

A photodetector includes an insulating layer on a substrate, a first graphene layer on the insulating layer, a 2-dimensional (2D) material layer on the first graphene layer, a second graphene layer on the 2D material layer, a first electrode on the first graphene layer, and a second electrode on the second graphene layer. The 2D material layer includes a barrier layer and a light absorption layer. The barrier layer has a larger bandgap than the light absorption layer.

A semiconductor device includes an insulating substrate, a semiconductor element secured to a top surface of the insulating substrate, a case formed of a resin and having a frame portion surrounding the semiconductor element, a metal support located above the insulating substrate and having an end secured to the frame portion, a holding-down portion extending downward from the metal support so as to prevent upwardly convex bending of the insulating substrate, and an adhesive bonding the insulating substrate and the case together.

A method of evaluating a semiconductor device having an insulated gate formed of a metal-oxide film semiconductor. The semiconductor device has a high potential side and a low potential side, and a threshold voltage that is a minimum voltage for forming a conducting path between the high and low potential sides. The method includes determining a variation of the threshold voltage at turn-on of the semiconductor device by continuously applying an alternating current (AC) voltage to the gate of the semiconductor device, a maximum voltage of the AC voltage being equal to or higher than the threshold voltage of the semiconductor device.