Abstract:
To improve characteristics of a semiconductor device. A first p-type semiconductor region having an impurity of a conductivity type opposite from that of a drift layer is arranged in the drift layer below a trench, and a second p-type semiconductor region is further arranged that is spaced at a distance from a region where the trench is formed as seen from above and that has the impurity of the conductivity type opposite from that of the drift layer. The second p-type semiconductor region is configured by a plurality of regions arranged at a space in a Y direction (depth direction in the drawings). Thus, it is possible to reduce the specific on-resistance while maintaining the breakdown voltage of the gate insulating film by providing the first and second p-type semiconductor regions and further by arranging the second p-type semiconductor region spaced by the space.
Abstract:
First and second p-type semiconductor regions (electric-field relaxation layers) are formed by ion implantation using a dummy gate and side wall films on both sides of the dummy gate as a mask. In this manner, it is possible to reduce a distance between the first p-type semiconductor region and a trench and a distance between the second p-type semiconductor region and the trench, and symmetry of the first and second p-type semiconductor regions with respect to the trench can be enhanced. As a result, semiconductor elements can be miniaturized, and on-resistance and an electric-field relaxation effect, which are in a trade-off relationship, can be balanced, so that characteristics of the semiconductor elements can be improved.
Abstract:
Semiconductor device has a cell region and a peripheral region, and has a drift layer, a trench, an gate dielectric film on an inner wall of the trench, a gate electrode, and a p-type first semiconductor region below the trench in the cell region on a semiconductor substrate. Further, in the peripheral region on the semiconductor substrate, p-type second semiconductor region is formed in the same layer as the p-type first semiconductor region. a width of the p-type first semiconductor region and a width of the p-type second semiconductor region are different.
Abstract:
A semiconductor device includes: a first conductivity type semiconductor substrate made of silicon carbide; a second conductivity type body region in a device region of the semiconductor substrate; a first conductivity type source region formed in the body region; and a gate electrode formed on the body region through gate insulating films. The semiconductor device further includes, in a termination region of the semiconductor substrate, second conductivity type RESURF layers, and an edge termination region formed in the RESURF layers. Then, the RESURF layers and a front surface of the semiconductor substrate adjacent to the RESURF layers are covered by an oxidation-resistant insulating film.
Abstract:
The present invention makes it possible to improve the accuracy of wet etching and miniaturize a semiconductor device in the case of specifying an active region of a vertical type power MOSFET formed over an SiC substrate by opening an insulating film over the substrate by the wet etching. After a silicon oxide film having a small film thickness and a polysilicon film having a film thickness larger than the silicon oxide film are formed in sequence over an epitaxial layer, the polysilicon film is opened by a dry etching method, successively the silicon oxide film is opened by a wet etching method, and thereby the upper surface of the epitaxial layer in an active region is exposed.
Abstract:
To provide a semiconductor device having a vertical JFET excellent in off-state performance without reducing a production yield. A gate region quadrangular in the cross-section along a channel width direction is formed below a source region by impurity ion implantation. By first etching, the source region over the upper surface of the gate region is removed to separate therebetween. Then, the upper surface of the gate region is processed by second etching having an etching rate lower at the side surface than at the center of the gate region. The resulting gate region has a lower surface parallel to the substrate surface and an upper surface below a boundary between the source region and the channel formation region and having, in the cross-section along the channel width direction, a downward slope from the side surface to the center. As a result, a channel length with reduced variations can be obtained.