To improve an on-resistance of a semiconductor device. A plurality of collector regions are formed at a predetermined interval on a bottom surface of a drift layer made of SiC. Next, on the bottom surface of the drift layer, both of the drift layer and a collector region via a silicide layer are connected to a collector electrode.

Provided is a semiconductor device including a drift region, a base region, two trench portions and a mesa portion, wherein at least one of the two trench portions is a gate trench portion, the mesa portion includes: a first conductivity type emitter region provided to be exposed on an upper surface of the mesa portion; a second conductivity type contact region provided to be exposed on the upper surface of the mesa portion alternately with the emitter region in an extending direction; and a second conductivity type connecting region with a higher doping concentration than the base region, wherein the connecting region is provided to overlap with the emitter region in a top view, is arranged apart from the gate trench portion, is arranged below the upper surface of the mesa portion, and connects two of the contact regions sandwiching the emitter region in the extending direction.

A method of forming a laterally varying dopant concentration profile of an electrically activated dopant in a power semiconductor device includes: providing a semiconductor body; implanting a dopant to form a doped region in the semiconductor body; providing, above the doped region, a mask layer having a first section and a second section, the first section having has a first thickness along a vertical direction and the second section having a second thickness along the vertical direction, the second thickness being different from the first thickness; and subjecting the doped region and both mask sections to a laser thermal annealing, LTA, processing step.

A semiconductor device includes: a first electrode; a first semiconductor layer on the first electrode in a diode region; a second semiconductor layer on the first electrode in an IGBT region; a semiconductor layer on the first and second semiconductor layers, a first upper layer of the semiconductor layer in the diode region including a first region adjacent to the IGBT region and a second region separated from the IGBT region, an impurity concentration being less in the first region than in the second region; a third semiconductor layer on the semiconductor layer; a fourth semiconductor layer of the third semiconductor layer in the IGBT region; a third electrode extending in a direction from the fourth semiconductor layer toward the semiconductor layer; and an insulating film between the second electrode and each of the third semiconductor layer, the semiconductor layer, and the third electrode.

Provided here are methods and manufacturing systems to implant protons into SiC IGBT devices at multiple depths in the drift layer of the SiC IGBT device. Provides are SiC IGBT devices manufactured with process steps including multiple proton implant processes where the SiC IGBT device is irradiated with ion to affect proton implantation into the SiC IGBT device at multiple depths in the drift region to reduced minority carrier lifetime.

A semiconductor device includes a semiconductor substrate in which a first region having a freewheeling diode arranged therein, second regions having an IGBT arranged therein, and a withstand-voltage retention region surrounding the first region and the second regions in plan view are defined. The semiconductor substrate has a first main surface and a second main surface. The semiconductor substrate includes an anode layer having a first conductivity type, which is arranged in the first main surface of the first region, and a diffusion layer having the first conductivity type, which is arranged in the first main surface of the withstand-voltage retention region adjacently to the anode layer. A first trench is arranged in the first main surface on a side of the anode layer with respect to a boundary between the anode layer and the diffusion layer.

An npnp layered switch is modified to have a composite anode structure. Instead of the continuous p-type bottom anode layer of a typical npnp IGTO device, thyristor, or IGBT, the composite anode is formed of a segmented p-type layer with gaps containing n-type semiconductor material. The n-type material forms a majority carrier path between the bottom anode electrode and the n-type collector of the vertical npn bipolar transistor. When a trenched gate is biased high, the majority carrier path is created between the bottom anode electrode and the top cathode electrode. Such a current path operates at very low operating voltages, starting at slightly above 0 volts. Above operating voltages of about 1.0 volts, the npnp layered switch operates normally and uses regenerative bipolar transistor action to conduct a vast majority of the current. The two current paths conduct in parallel.

After the various regions of a vertical power device are formed in or on the top surface of an n-type wafer, the wafer is thinned, such as by grinding. A drift layer may be n-type, and various n-type regions and p-type regions in the top surface contact a top metal electrode. A blanket dopant implant through the bottom surface of the thinned wafer is performed to form an n− buffer layer and a bottom p+ emitter layer. Energetic particles are injected through the bottom surface to intentionally damage the crystalline structure. A wet etch is performed, which etches the damaged crystal at a much greater rate, so some areas of the n− buffer layer are exposed. The bottom surface is metallized. The areas where the metal contacts the n− buffer layer form cathodes of an anti-parallel diode for conducting reverse voltages, such as voltage spikes from inductive loads.

Provided in the present disclosure are an IGBT device backside structure and a preparation method therefor, and an IGBT device, the IGBT device backside structure comprising a buffer layer, the buffer layer comprising a first activation efficiency buffer area corresponding to an active area of the IGBT device and a second activation efficiency buffer area corresponding to a terminal area of the IGBT device, the activation efficiency of the first activation efficiency buffer area being less than the activation efficiency of the second activation efficiency buffer area.

A diode region includes: an n-type first semiconductor layer provided on a second-main-surface side in the semiconductor substrate; an n-type second semiconductor layer provided on the first semiconductor layer; a p-type third semiconductor layer provided closer to a first main surface of the semiconductor substrate than the second semiconductor layer; a first main electrode that applies a first potential to the diode; a second main electrode that applies a second potential to the diode; and a dummy active trench gate provided so as to extend from the first main surface of the semiconductor substrate and reach the second semiconductor layer. The dummy active trench gate includes the third semiconductor layer that is not applied with the first potential to be in a floating state on at least one of two side surfaces, and the dummy active trench gate is applied with a gate potential of the transistor.