A semiconductor device includes: a SiC substrate; a device structure in or on the SiC substrate and subject to an electric field during operation of the semiconductor device; a current-conduction region of a first conductivity type in the SiC substrate adjoining the device structure; and a shielding region of a second conductivity type laterally adjacent to the current-conduction region and configured to at least partly shield the device structure from the electric field. The shielding region has a higher net doping concentration than the current-conduction region, and has a length (L) measured from a first position which corresponds to a bottom of the device structure to a second position which corresponds to a bottom of the shielding region. The current-conduction region has a width (d) measured between opposing lateral sides of the current-conduction region, and L/d is in a range of 1 to 10.

The present application discloses an SiC MOSFET device, including an SiC epitaxial layer in which a trench gate is formed, wherein a first bottom doped region is formed below a bottom surface of a gate trench, a second deep doped region with spacing from the gate trench is formed in the SiC epitaxial layer, the first bottom doped region is connected to a source so that voltage borne by a gate dielectric layer on the bottom surface of the gate trench is determined by gate-source voltage; the second deep doped region extends downward from a top surface of the SiC epitaxial layer, and a bottom surface of the second deep doped region is located below a bottom surface of the first bottom doped region; a top of the second deep doped region is connected to the source. The present application further discloses a method for manufacturing an SiC MOSFET device.

A semiconductor device with a junction type FET includes: a drift layer; a channel layer on the drift layer; a source layer in a surface portion of the channel layer; a gate layer in the channel layer; a body layer in the channel layer; a drain layer disposed on an opposite side of the source layer with respect to the drift layer; a gate wiring electrically connected to the gate layer; a first electrode electrically connected to the source layer and the body layer; and a second electrode electrically connected to the drain layer.

A semiconductor wafer includes a silicon carbide wafer and an epitaxial layer, which is disposed at a surface of the silicon carbide wafer and made of silicon carbide. The semiconductor wafer satisfies a condition that a waviness value is equal to or smaller than 1 micrometer. The waviness value is a sum of an absolute value of a value α and an absolute value of a value β. A highest height among respective heights of a plurality of points with reference to a surface reference plane within a light exposure area is denoted as the value α. A lowest height among the respective heights of the points at the epitaxial layer with reference to the surface reference plane within the light exposure area is denoted as the value β.

A semiconductor device includes a semiconductor layer structure that comprises silicon carbide, a gate dielectric layer on the semiconductor layer structure, the gate dielectric layer including a base gate dielectric layer that is on the semiconductor layer structure and a capping gate dielectric layer on the base gate dielectric layer opposite the semiconductor layer structure, and a gate electrode on the gate dielectric layer opposite the semiconductor layer structure. A dielectric constant of the capping gate dielectric layer is higher than a dielectric constant of the base gate dielectric layer.

Self-aligned FET devices and associated fabrication methods are disclosed herein. A disclosed process for forming a FET includes forming a first mask, implanting a deep well region in a drift region using the first mask, forming a spacer in contact with the first mask, and implanting a shallow well region in the drift region using the first mask and the spacer. A disclosed FET includes a drift region, a shallow well region, a deep well region located between the shallow well region and the drift region, and a junction field effect region: in contact with the shallow well region, the drift region, and the deep well region; and having a junction field effect doping concentration of the first conductivity type. The FETs can include a hybrid channel formed by a portion of the junction field effect region, as influenced by the deep well region, and the shallow well region.

A semiconductor device includes a semiconductor layer structure and a gate formed in a gate trench in the semiconductor layer structure. The gate trench has a bottom surface comprising a first portion at a first level and a second portion at a second level, different from the first level. A method of forming a semiconductor device includes providing a semiconductor layer structure, etching a first gate trench into the semiconductor layer structure, etching a second gate trench into the semiconductor layer structure, and performing an ion implantation into a bottom surface of the second gate trench. The second gate trench is deeper than the first gate trench, and at least a portion of the second gate trench is connected to the first gate trench.

A semiconductor device includes: a silicon carbide semiconductor body having a source region of a first conductivity type and a body region of a second conductivity type; and a trench structure extending from a first surface into the silicon carbide semiconductor body along a vertical direction, the trench structure having a gate electrode and a gate dielectric. The trench structure is stripe-shaped and runs along a longitudinal direction that is perpendicular to the vertical direction. The source region includes a first source sub-region and a second source sub-region alternately arranged along the longitudinal direction. A doping concentration profile of the first source sub-region along the vertical direction differs from a doping concentration profile of the second source sub-region along the vertical direction. A corresponding method of manufacturing the semiconductor device is also described.

A semiconductor device includes: a semiconductor substrate; a semiconductor layer of a first conductivity type that is deposited on a surface of the semiconductor substrate; a trench that is formed on a surface of the semiconductor layer; an insulating film that covers a bottom surface of the trench and a lateral surface of the trench; a conductive body that fills inside the trench that is covered by the insulating film; a second conductive type region that is formed in the semiconductor layer, is arranged under the trench, and is within a region of the trench in a plan view of the semiconductor substrate; and a metal film that is electrically connected to the conductive body and forms a Schottky barrier with the surface of the semiconductor layer.

A semiconductor device includes a semiconductor layer structure and a gate formed in a gate trench in the semiconductor layer structure. The gate trench has a bottom surface comprising a first portion at a first level and a second portion at a second level, different from the first level. A method of forming a semiconductor device includes providing a semiconductor layer structure, etching a first gate trench into the semiconductor layer structure, etching a second gate trench into the semiconductor layer structure, and performing an ion implantation into a bottom surface of the second gate trench. The second gate trench is deeper than the first gate trench, and at least a portion of the second gate trench is connected to the first gate trench.