Patent application number | Description | Published |
20090272983 | Silicon carbide semiconductor device and method for manufacturing the same - A silicon carbide semiconductor device includes: a semiconductor substrate having a silicon carbide substrate, a first semiconductor layer, a second semiconductor layer, and a third semiconductor layer; a trench penetrating the second and the third semiconductor layers to reach the first semiconductor layer; a channel layer on a sidewall and a bottom of the trench; an oxide film on the channel layer; a gate electrode on the oxide film; a first electrode connecting to the third semiconductor layer; and a second electrode connecting to the silicon carbide substrate. A position of a boundary between the first semiconductor layer and the second semiconductor layer is disposed lower than an utmost lowest position of the oxide film. | 11-05-2009 |
20140145212 | SILICON CARBIDE SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME - A semiconductor device includes a silicon carbide semiconductor substrate, a transistor formed in a cell region of the semiconductor substrate, and a voltage-breakdown-resistant structure formed in a region which surrounds an outer periphery of the cell region. The semiconductor substrate includes a first conductivity type substrate, a first conductivity type drift layer on the first conductivity type substrate, a second conductivity type layer on the drift layer, and a first conductivity type layer on the second conductivity type layer. The voltage-breakdown-resistant structure includes a first recess which surrounds the outer periphery of the cell region and reaches the drift layer, a trench located at a side surface of the recess on an inner periphery of the recess, and a second conductivity type buried layer buried in the trench to provide the side surface of the first recess. | 05-29-2014 |
20140159058 | SILICON CARBIDE SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD OF SILICON CARBIDE SEMICONDUCTOR DEVICE - In a silicon carbide semiconductor device, a trench penetrates a source region and a first gate region and reaches a drift layer. On an inner wall of the trench, a channel layer of a first conductivity-type is formed by epitaxial growth. On the channel layer, a second gate region of a second conductivity-type is formed. A first depressed portion is formed at an end portion of the trench to a position deeper than a thickness of the source region so as to remove the source region at the end portion of the trench. A corner portion of the first depressed portion is covered by a second conductivity-type layer. | 06-12-2014 |
20150048382 | SILICON CARBIDE SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - In a silicon carbide semiconductor device, a p-type SiC layer is disposed in a corner of a bottom of a trench. Thus, even if an electric field is applied between a drain and a gate when a MOSFET is turned off, a depletion layer in a pn junction between the p-type SiC layer and an n | 02-19-2015 |
20150072485 | MANUFACTURING METHOD FOR SILICON CARBIDE SEMICONDUCTOR DEVICE - In a method of manufacturing a silicon carbide semiconductor device having a JFET, after forming a second concave portion configuring a second mesa portion, a thickness of a source region is detected by observing a pn junction between the source region and a first gate region exposed by the second concave portion. Selective etching is conducted on the basis of the detection result to form a first concave portion deeper than the thickness of the source region and configuring a first mesa portion inside of an outer peripheral region in an outer periphery of a cell region, and to make the second concave portion deeper than the second gate region. | 03-12-2015 |
20150072486 | METHOD FOR MANUFACTURING SILICON CARBIDE SEMICONDUCTOR DEVICE - In a method for manufacturing a silicon carbide semiconductor device having a JFET, a trench is formed in a semiconductor substrate, and a channel layer and a second gate region are formed on an inner wall of the trench. The channel layer and the second gate region are planarized to expose a source region. A first recess deeper than a thickness of the source region is formed on both leading ends of the trench, and an activation annealing process of 1300° C. or higher is conducted in an inert gas atmosphere. A first conductivity type layer formed by the annealing process to cover a corner which is a boundary between a bottom and a side of the first recess is removed. | 03-12-2015 |
20150115286 | SILICON CARBIDE SEMICONDUCTOR DEVICE AND METHOD FOR PRODUCING THE SAME - An SiC semiconductor device has a p type region including a low concentration region and a high concentration region filled in a trench formed in a cell region. A p type column is provided by the low concentration region, and a p | 04-30-2015 |
20150129895 | SILICON CARBIDE SEMICONDUCTOR DEVICE AND METHOD FOR PRODUCING THE SAME - In a method for producing an SiC semiconductor device, a p type layer is formed in a trench by epitaxially growing, and is then left only on a bottom portion and ends of the trench by hydrogen etching, thereby to form a p type SiC layer. Thus, the p type SiC layer can be formed without depending on diagonal ion implantation. Since it is not necessary to separately perform the diagonal ion implantation, it is less likely that a production process will be complicated due to transferring into an ion implantation apparatus, and thus manufacturing costs reduce. Since there is no damage due to a defect caused by the ion implantation, it is possible to reduce a drain leakage and to reliably restrict the p type SiC layer from remaining on the side surface of the trench. | 05-14-2015 |