Abstract: A semiconductor device includes a first conductive type semiconductor substrate, a second conductive type active region formed on a top surface side of the semiconductor substrate, a second conductive type inside VLD region formed to contact the active region on the top surface side in a plan view, and a second conductive type well region formed to contact a portion opposite to the portion contacting the active region of the inside VLD region on the top surface side in a plan view. The well region is formed to be deeper than the active region. The inside VLD region has the same depth as that of the active region in the portion contacting the active region, the depth gradually increasing from the active region toward the well region and becoming the same as the depth of the well region in the portion contacting the well region.

Abstract: A semiconductor device includes a substrate of a first conductivity type, a first impurity region of a second conductivity type formed on a top surface side of the substrate, a second impurity region of the second conductivity type formed on the top surface side of the substrate and in contact with the first impurity region, the second impurity region laterally surrounding the first impurity region and having a greater depth than the first impurity region, as viewed in cross-section, and a breakdown voltage enhancing structure of the second conductivity type formed to laterally surround the second impurity region. A boundary between the first and second impurity regions has a maximum impurity concentration equal to or less than that of the second impurity region, and a current is applied between a top surface and a bottom surface of the substrate.

Abstract: A semiconductor device includes a semiconductor chip with a gate electrode, and a stress detecting element placed on a surface of the semiconductor chip, and which detects stress applied to the surface. The semiconductor device controls a control signal to be applied to the gate electrode in response to stress detected by the stress detecting element. The stress detecting element is preferably provided as a first stress detecting element which detects stress applied to a central portion of the semiconductor chip in plan view. The stress detecting element is preferably provided as a second stress detecting element which detects stress applied to a circumferential portion of the semiconductor chip in plan view.

Abstract: A semiconductor device includes a first conductive type semiconductor substrate, a second conductive type active region formed on a top surface side of the semiconductor substrate, a second conductive type inside VLD region formed to contact the active region on the top surface side in a plan view, and a second conductive type well region formed to contact a portion opposite to the portion contacting the active region of the inside VLD region on the top surface side in a plan view. The well region is formed to be deeper than the active region. The inside VLD region has the same depth as that of the active region in the portion contacting the active region, the depth gradually increasing from the active region toward the well region and becoming the same as the depth of the well region in the portion contacting the well region.

Abstract: A semiconductor device using one or more guard rings includes a p-type guard ring region surrounding a pn junction region, an insulating film covering the p-type guard ring region, one or more conductive films electrically connected with the p-type guard ring region through one or more contact holes made in the insulating film, and a semi-insulating film covering the insulating film and the conductive films. Thus, a desired breakdown voltage characteristic can be ensured even if a foreign matter or the like adheres to a surface of the conductive films.

Abstract: A power semiconductor device of the present invention has an active region and an electric field reduction region and includes: an emitter region of a first conductivity type; a base region of a second conductivity type in contact with the emitter region; an electrical strength providing region of the first conductivity type in contact with the base region; a collector region of the second conductivity type in contact with the electrical strength providing region; and a collector electrode in contact with the collector region; wherein the collector region is disposed on both a active region and a electric field reduction region each containing a dopant of the second conductivity type, and the collector region disposed on the electric field reduction region includes a region having a lower density of carriers of the second conductivity type than the collector region disposed on the active region.

Abstract: A semiconductor wafer has a main surface. A main chip region is formed on the main surface. A sub-chip region is smaller in area than the main chip region, and positioned on an edge side of the semiconductor wafer relative to the main chip region. The sub-chip region is identical to the main chip region in design pattern. Accordingly, a semiconductor device in which occurrence of a pattern failure at the edge of the wafer can be prevented when chips are arranged in the surface of the semiconductor wafer and a method of manufacturing the same can be obtained.

Abstract: A method of testing a semiconductor device includes a conductive foreign matter test step of measuring the resistance value between the first and second conductive patterns to determine whether conductive foreign matter is present between the first and second conductive patterns, a first open circuit test step of measuring the resistance value between two points on the first conductive pattern to determine whether there is an open circuit in the first conductive pattern, and a second open circuit test step of measuring the resistance value between two points on the second conductive pattern to determine whether there is an open circuit in the second conductive pattern. The measurement of the resistance value in each of the test steps is accomplished by pressing probes vertically against the first conductive pattern or the second conductive pattern or both.

Abstract: A semiconductor layer has a first layer of first conductive type, a second layer of second conductive type, and a third layer. The third layer has a first region of first conductive type, and a second region of second conductive type. A second electrode is in contact with each of the first and second regions. A trench is formed on the semiconductor layer at a surface opposite to its surface facing a first electrode. A gate electrode is embedded in the trench with a gate insulating film interposed therebetween. The gate electrode includes a first portion projecting into the first layer through the first region and the second layer, a second portion projecting into the first layer through the second region and the second layer. The second portion projects into the first layer deeper than a depth in which the first portion projects into the first layer.

Abstract: A semiconductor device includes a trench extending from a surface of a P-base layer to a surface of a P-well layer. The trench has a trench end portion defined in the surface of the P-well layer and in a direction in which the trench extends. The trench has first and second regions. The first region extends from the trench end portion to get into the surface of the P-base layer near a boundary between the P-base layer and the P-well layer. The second region extends in the surface of the P-base layer from an end portion of the first region. A trench width is greater in the first region than in the second region.

Abstract: A measurement terminal is arranged at an edge of a semiconductor wafer to be apart from a gate electrode and a source electrode formed in a surface portion on one side in a thickness direction of a semiconductor wafer so that an electrode contact portion is in contact with a drain electrode on the other side in the thickness direction of the semiconductor wafer and that a terminal contact portion is exposed to the one side in the thickness direction of the semiconductor wafer. A probe terminal is brought into contact with the terminal contact portion of the measurement terminal and the probe terminal is brought into contact with the gate electrode and the source electrode, to thereby measure electrical characteristics of a MOSFET.

Abstract: A method of manufacturing a power semiconductor device according to the present invention includes the steps of: (a) forming a silicon nitride film on a semiconductor substrate; (b) after the step (a), forming a ring-shaped trench along a peripheral portion of the semiconductor substrate 6; (c) forming a first silicon oxide film on an inner surface of the trench; (d) after the step (c), forming a second silicon oxide film on an entire surface of the semiconductor substrate to bury the trench; (e) planarizing the second silicon oxide film by using the silicon nitride film as a stopper; and (f) forming a third silicon oxide film in a region in which the silicon nitride film is removed.

Abstract: A passivation film having a predetermined width from an outer peripheral end portion toward an inner side and extending along the outer peripheral end portion is formed on a front surface of a semiconductor substrate. An outer peripheral end surface orthogonal to the front surface and a rear surface is formed by grinding the outer peripheral end portion of the semiconductor substrate. A thickness of the semiconductor substrate is reduced to a predetermined thickness by grinding the rear surface. The ground rear surface is etched by discharging a mixed acid onto the rear surface while rotating the semiconductor substrate with the rear surface facing upward, to remove a fracture layer. Thereby, chipping or cracking of the semiconductor substrate is suppressed.

Abstract: A method for manufacturing a semiconductor device wherein a semiconductor element is sealed with mold resin, a MOS structure is on an upper side of the semiconductor chip, and a PN junction region is on a back side of the semiconductor chip, comprises: obtaining an in-plane distribution of impurity concentration of the PN junction region in the semiconductor chip before encapsulation so that an in-plane distribution of breakdown voltage and leakage current of the semiconductor chip become uniform after encapsulation; forming the PN junction region having the obtained in-plane distribution of impurity concentration on the back side of the semiconductor chip; and sealing the semiconductor chip with the resin after forming the PN junction region.

Abstract: A semiconductor device includes a base layer that has a first conductivity type, a source layer that is formed on the base layer and has a second conductivity type, and an insulating film that is formed on the source layer. The semiconductor device further includes a plurality of gate structures that penetrate the base layer, and a plurality of conductive parts that penetrate the insulating film and the source layer and electrically connect the source layer and the base layer to each other. The gate structures are formed in a stripe shape in plan view. Parts in which the conductive portion is connected to the base layer are formed in a stripe shape in plan view, and are formed between the gate structures. Further, a dimension of the part in which the source layer and the base layer are in contact with each other between the gate structure and the conductive portion is 0.36 ?m or more.

Abstract: A semiconductor device includes a semiconductor chip with a gate electrode, and a stress detecting element placed on a surface of the semiconductor chip, and which detects stress applied to the surface. The semiconductor device controls a control signal to be applied to the gate electrode in response to stress detected by the stress detecting element. The stress detecting element is preferably provided as a first stress detecting element which detects stress applied to a central portion of the semiconductor chip in plan view. The stress detecting element is preferably provided as a second stress detecting element which detects stress applied to a circumferential portion of the semiconductor chip in plan view.

Abstract: A semiconductor device includes a trench extending from a surface of a P-base layer to a surface of a P-well layer. The trench has a trench end portion defined in the surface of the P-well layer and in a direction in which the trench extends. The trench has first and second regions. The first region extends from the trench end portion to get into the surface of the P-base layer near a boundary between the P-base layer and the P-well layer. The second region extends in the surface of the P-base layer from an end portion of the first region. A trench width is greater in the first region than in the second region.

Abstract: A semiconductor wafer having IGBT elements and transistors formed on a surface thereof is prepared. Electron beams are emitted all over the surface of the semiconductor wafer. Recombination centers are formed in the IGBT elements and the transistors. ON voltages of the transistors are measured by a measurement device, and lifetimes defined in the IGBT elements and the transistors are recovered by a prescribed annealing treatment. When the lifetimes are recovered, a control device controls an annealing treatment amount in the annealing treatment based on the measured ON voltages of the transistors such that ON voltages of the IGBT elements are each equal to a desired ON voltage. Variations in the ON voltages of a plurality of IGBT elements obtained from the semiconductor wafer are reduced.

Abstract: A mask layer having a plurality of openings is formed on the first layer. A second layer having a second conductivity type different from the first conductivity type is formed on the first layer by introducing impurities using the mask layer. A third layer having the first conductivity type is formed on the second layer by introducing impurities using the mask layer. A trench extending through the second layer and the third layer to the first layer is formed by carrying out etching using an etching mask including at least the mask layer. A gate insulation film covering a sidewall of the trench is formed. A trench gate filling the trench is formed on the gate insulation film.

Abstract: A measurement terminal is arranged at an edge of a semiconductor wafer to be apart from a gate electrode and a source electrode formed in a surface portion on one side in a thickness direction of a semiconductor wafer so that an electrode contact portion is in contact with a drain electrode on the other side in the thickness direction of the semiconductor wafer and that a terminal contact portion is exposed to the one side in the thickness direction of the semiconductor wafer. A probe terminal is brought into contact with the terminal contact portion of the measurement terminal and the probe terminal is brought into contact with the gate electrode and the source electrode, to thereby measure electrical characteristics of a MOSFET.