The present invention provides a bipolar transistor, a method for forming the bipolar transistor, a method for turning on the bipolar transistor, and a band-gap reference circuit, virtual ground reference circuit and double band-gap reference circuit with the bipolar transistor. The bipolar transistor includes: a Silicon-On-Insulator wafer; a base area, an emitter area and a collector area; a base area gate dielectric layer on a top silicon layer and atop the base area; a base area control-gate on the base area gate dielectric layer; an emitter electrode connected to the emitter area via a first contact; a collector electrode connected to the collector area via a second contact; and a base area control-gate electrode connected to the base area control-gate via a third contact. Processes of forming the bipolar transistor are fully compatible with traditional standard CMOS processes; and the base current to turn on the bipolar transistor is based on the GIDL current and formed by applying a voltage to the base area control-gate electrode without any need of contact to the base.

A method for treating a semiconductor wafer having a basic doping is disclosed. The method includes determining a doping concentration of the basic doping, and adapting the basic doping of the semiconductor wafer by postdoping. The postdoping includes at least one of the following methods: a proton implantation and a subsequent thermal process for producing hydrogen induced donors. In this case, at least one of the following parameters is dependent on the determined doping concentration of the basic doping: an implantation dose of the proton implantation, and a temperature of the thermal process.

A method for forming a semiconductor device includes carrying out an anodic oxidation of a surface region of a semiconductor substrate to form an oxide layer at a surface of the semiconductor substrate by generating an attracting electrical field between the semiconductor substrate and an external electrode within an electrolyte to attract oxidizing ions of the electrolyte, causing an oxidation of the surface region of the semiconductor substrate. Further, the method includes reducing the number of remaining oxidizing ions within the oxide layer, while the semiconductor substrate is within an electrolyte.

A method of manufacturing a silicon carbide semiconductor device includes forming a constituent layer and forming a super junction structure. The formation of the super junction structure includes forming a film-forming mask on the constituent layer, forming an opening portion at the film-forming mask, forming a mask-forming trench at the constituent layer and adopting a portion of the constituent layer surrounding the mask-forming trench as a silicon carbide mask through etching by adopting the film-forming mask, forming a second-conductivity-type column region by ion implantation of impurities at a bottom surface of the mask-forming trench by adopting an ion-implantation mask having the film-forming mask and the silicon carbide mask, and removing a portion of the constituent layer where the silicon carbide mask is formed.

Heterostructure and double-heterostructure trench-gate devices, in which the substrate and/or the body are constructed of a narrower-bandgap semiconductor material than the uppermost portion of the drift region. Fabrication most preferably uses a process where gate dielectric anneal is performed after all other high-temperature steps have already been done.

A method of fabricating a wide bandgap device includes providing a thin native substrate. An epitaxial layer is grown on a surface of the native substrate. After growing the epitaxial layer, a handle substrate is attached to the opposite surface of the native substrate by way of an interface layer. With the handle substrate providing mechanical support, wide bandgap devices are fabricated in the epitaxial layer using a low-temperature fabrication process. The handle substrate is detached from the native substrate after fabrication of the wide bandgap devices.

A semiconductor device comprising a semiconductor substrate including an upper surface and a lower surface wherein a donor concentration of a drift region is higher than a base doping concentration of the semiconductor substrate, entirely over the drift region in a depth direction connecting the upper surface and the lower surface is provided.

A semiconductor device having a first load terminal, a second load terminal and a semiconductor body is presented. The semiconductor body comprises an active region configured to conduct a load current between the first load terminal and the second load terminal and a junction termination region surrounding the active region. The semiconductor body includes a drift layer arranged within both the active region and the junction termination region and having dopants of a first conductivity type at a drift layer dopant concentration of equal to or less than 10.sup.14 cm.sup.3; a body zone arranged in the active region and having dopants of a second conductivity type complementary to the first conductivity type and isolating the drift layer from the first load terminal; a guard zone arranged in the junction termination region and having dopants of the second conductivity type and being configured to extend a depletion region formed by a transition between the drift layer and the body zone; a field stop zone arranged adjacent to the guard zone, the field stop zone having dopants of the first conductivity type at a field stop zone dopant concentration that is higher than the drift layer dopant concentration by a factor of at least 2; a low doped zone arranged adjacent to the field stop zone, the low doped zone having dopants of the first conductivity type at a dopant concentration that is lower than the drift layer dopant concentration by a factor of at least 1.5, wherein the body zone, the guard zone, the field stop zone and the low doped zone are arranged in the semiconductor body such that they exhibit a common depth range (DR) of at least 1 m along a vertical extension direction (Z).

A silicon carbide semiconductor device includes a silicon carbide substrate having a first main surface and a second main surface opposite to the first main surface. A gate trench is provided in the first main surface. The gate trench is defined by side surfaces and a bottom surface. The side surfaces penetrate the source region and the body region to reach the drift region. The bottom surface connects to the side surfaces. The gate trench extends in a first direction parallel to the first main surface. The silicon carbide substrate further includes an electric field relaxation region that is the second conductive type, the electric field relaxation region being provided between the bottom surface and the second main surface and extending in the first direction, and a connection region that is the second conductive type, the connection region electrically connecting a contact region to the electric field relaxation region. In a plan view in a direction normal to the first main surface, the gate trench and the electric field relaxation region are disposed on a virtual line that extends in the first direction, and the connection region is in contact with the electric field relaxation region on the virtual line.

There is provided a semiconductor device including: a drift region of a first conductivity type disposed in a semiconductor substrate; a base region of a second conductivity type disposed above the drift region; an emitter region of the first conductivity type disposed above the base region; a plurality of trench portions arrayed in a predetermined array direction on a front surface side of the semiconductor substrate; a trench contact disposed on the front surface side of the semiconductor substrate between two adjacent trench portions; and a contact layer of the second conductivity type disposed under the trench contact and having a higher doping concentration than the base region, wherein a lower end of the trench contact is deeper than a lower end of the emitter region, and the emitter region and the contact layer are in contact with each other at a side wall of the trench contact.