According to an aspect of the present disclosure, a semiconductor device includes a substrate including an IGBT region, and a diode region, a surface electrode provided on a top surface of the substrate and a back surface electrode provided on a back surface on an opposite side to the top surface of the substrate, wherein the diode region includes a first portion formed to be thinner than the IGBT region by the top surface of the substrate being recessed, and a second portion provided on one side of the first portion and thicker than the first portion.

The object is to provide a semiconductor device that prevents a snapback operation and has excellent heat dissipation. The semiconductor device includes a semiconductor substrate, transistor portions, diode portions, a surface electrode, and external wiring. The transistor portions and the diode portions are provided in the semiconductor substrate and are arranged in one direction parallel with the surface of the semiconductor substrate. A bonding portion of the external wiring is connected to the surface electrode. The transistor portions and the diode portions are provided in a first region and a second region and alternately arranged in the one direction. A first transistor width and a first diode width in the first region are smaller than a width of the bonding portion. A second transistor width and a second diode width in the second region are larger than the width of the bonding portion.

There is disclosed the integration of a Schottky diode with a MOSFET, more in detail there is a free-wheeling Schottky diode and a power MOSFET on top of a buried grid material structure. Advantages of the specific design allow the whole surface area to be used for MOSFET and Schottky diode structures, the shared drift layer is not limited by Schottky diode or MOSFET design rules and therefore, one can decrease the thickness and increase the doping concentration of the drift layer closer to a punch through design compared to the state of the art. This results in higher conductivity and lower on-resistance of the device with no influence on the voltage blocking performance. The integrated device can operate at higher frequency. The risk for bipolar degradation is avoided.

A semiconductor device includes a junction field effect transistor (JFET) including a source electrode, a drain electrode, and a gate electrode, and a metal oxide semiconductor field effect transistor (MOSFET) including a source electrode, a drain electrode, and a gate electrode. The JFET and the MOSFET are cascode-connected such that the source electrode of the JFET and the drain electrode of the MOSFET are electrically connected. A gate voltage dependency of the JFET or a capacitance ratio of a mirror capacitance of the MOSFET to an input capacitance of the MOSFET is adjusted in a predetermined range.

A semiconductor device includes a MOSFET including a drift layer, a channel layer, a trench gate structure, a source layer, a drain layer, a source electrode, and a drain electrode. The trench gate structure includes a trench penetrating the channel layer and protruding into the drift layer, a gate insulating film disposed on a wall surface of the trench, and a gate electrode disposed on the gate insulating film. A portion of the trench protruding into the drift layer is entirely covered with a well layer, and the well layer is connected to the channel layer.

In a semiconductor device, a semiconductor substrate has an IGBT region and a FWD, and includes a first conductivity type drift layer, a second conductivity type base layer disposed on the drift layer, a second conductivity type collector layer disposed opposite to the base layer with respect to the drift layer in the IGBT region, and a first conductivity type cathode layer disposed opposite to the base layer with respect to the drift layer in the FWD region. The collector layer includes an extension portion that covers only a part of the cathode layer on a side adjacent to the drift layer. Alternatively, the collector layer includes an extension portion that entirely covers a region of the cathode layer adjacent to the drift layer, and has an area density of 3.5×10.sup.12 cm.sup.−2 or less.

Provided is a semiconductor device including: a semiconductor substrate having a drift region of a first conductivity type; and a buffer region of the first conductivity type provided between the drift region and a lower surface of the semiconductor substrate and having a higher doping concentration than the drift region. The buffer region has two or more helium chemical concentration peaks arranged at different positions in a depth direction of the semiconductor substrate.

A semiconductor device includes a first transistor that flows a current to a load, a current generation circuit that outputs a current corresponding to a power consumption of the first transistor, a temperature sensor, a resistor-capacitor network coupled between the current generation circuit and the temperature sensor and an overheat detection circuit coupled to a connection point of the current generation circuit and the resistor-capacitor network, wherein the resistor-capacitor network comprises a resistor and a capacitor corresponding to a thermal resistance and a thermal capacitance between the first transistor and the temperature sensor.

Aspects of the present disclosure are directed to circuitry operable with enhanced capacitance and mitigation of avalanche breakdown. As may be implemented in accordance with one or more embodiments, an apparatus and/or method involves respective transistors of a cascode circuit, one of which controls the other in an off state by applying a voltage to a gate thereof. A plurality of doped regions are separated by trenches, with the conductive trenches being configured and arranged with the doped regions to provide capacitance across the source and the drain of the second transistor, and restricting voltage at one of the source and the drain of the second transistor, therein mitigating avalanche breakdown of the second transistor.

Plural sessions of proton irradiation are performed by differing ranges from a substrate rear surface side. After first to fourth n-type layers of differing depths are formed, the protons are activated. Next, helium is irradiated to a position deeper than the ranges of the proton irradiation from the substrate rear surface, introducing lattice defects. When the amount of lattice defects is adjusted by heat treatment, protons not activated in a fourth n-type layer are diffused, forming a fifth n-type layer contacting an anode side of the fourth n-type layer and having a carrier concentration distribution that decreases toward the anode side by a more gradual slope than that of the fourth n-type layer. The fifth n-type layer that includes protons and helium and the first to fourth n-type layers that include protons constitute an n-type FS layer. Thus, a semiconductor device having improved reliability and lower cost may be provided.