Abstract: A semiconductor device includes a transistor having a gate electrode, a first electrode, and a second electrode and first and second protection circuits each having one end commonly connected to the gate electrode and the other end connected to the first and second electrodes, respectively. The first and second protection circuits are formed in first and second polysilicon layers, respectively, formed separately on a single field insulating film.

Abstract: A semiconductor device includes a transistor having a gate electrode, a first electrode, and a second electrode and first and second protection circuits each having one end commonly connected to the gate electrode and the other end connected to the first and second electrodes, respectively. The first and second protection circuits are formed in first and second polysilicon layers, respectively, formed separately on a single field insulating film.

Abstract: A semiconductor device includes a transistor having a gate electrode, a first electrode, and a second electrode and first and second protection circuits each having one end commonly connected to the gate electrode and the other end connected to the first and second electrodes, respectively. The first and second protection circuits are formed in first and second polysilicon layers, respectively, formed separately on a single field insulating film.

Abstract: An improved coupling stability between the source region and the source electrode of the transistor is achieved. In the method for manufacturing the MOSFET, the p-type base region is formed in a semiconductor layer, and after the p-type base region is formed in the surface portion of the n+ type source region, the higher concentration source region extending from the side edge of the n+ type source region to the lateral side of the n+ type source region is formed in the surface portion of the p-type base region. Then, the source electrode coupled to the higher concentration source region is formed. This allows providing an improved coupling stability between the source electrode and the source region when a misalignment is occurred in the location for forming the source electrode during the formation of the source electrode to be coupled to the first source region.

Abstract: A semiconductor device contains a semiconductor substrate having a p-type semiconductor layer and an n-type channel layer formed thereon; gate trenches extended through the channel layer so as to reach the p-type semiconductor layer; oxide films formed over the bottom and inner wall of the gate trenches, the oxide films being formed thicker over the bottom of the gate trenches than over the inner wall; gate electrodes formed so as to fill the gate trenches; n-type regions formed at the bottom of the gate trenches, and containing arsenic as a major n-type impurity component; low concentration p-type regions formed under the n-type regions, and having a low p-type impurity concentration; and a drain electrode formed on the back surface of the substrate.

Abstract: An improved coupling stability between the source region and the source electrode of the transistor is achieved. In the method for manufacturing the MOSFET, the p-type base region is formed in a semiconductor layer, and after the p-type base region is formed in the surface portion of the n+ type source region, the higher concentration source region extending from the side edge of the n+ type source region to the lateral side of the n+ type source region is formed in the surface portion of the p-type base region. Then, the source electrode coupled to the higher concentration source region is formed. This allows providing an improved coupling stability between the source electrode and the source region when a misalignment is occurred in the location for forming the source electrode during the formation of the source electrode to be coupled to the first source region.

Abstract: In a semiconductor device, an active region is formed on a semiconductor substrate. An electrode layer is directly formed on the active region and serves as a bonding pad. The electrode layer is mainly formed by an Al alloy layer containing Cu.