Abstract: A semiconductor integrated circuit is reduced in size by suppressing lateral extension of an impurity region when impurities in the impurity region are thermally diffused in a semiconductor substrate. A second photoresist is formed on an insulation film. The second photoresist is formed to have second openings K2 on both sides of a P-type impurity region so that the second openings K2 partially overlap the P-type impurity region. The insulation film is etched off together with an underlying surface of the semiconductor substrate using the second photoresist as a mask so as to remove the P-type impurity region partially. Then, phosphorus ions (P+) are implanted into the surface of the semiconductor substrate in the etched-off regions using the second photoresist as a mask to form N-type impurity regions that are adjacent the P-type impurity region. After removing the second photoresist, the impurities in the P-type impurity region and the impurities in the N-type impurity region are thermally diffused.

Abstract: The invention is directed to reduction of a manufacturing cost and enhancement of a breakdown voltage of a PN junction portion abutting on a guard ring. An N? type semiconductor layer is formed on a front surface of a semiconductor substrate, and a P type semiconductor layer is formed thereon. An insulation film is formed on the P type semiconductor layer. Then, a plurality of grooves, i.e., a first groove, a second groove and a third groove are formed from the insulation film to the middle of the N? type semiconductor layer in the thickness direction thereof. The plurality of grooves is formed so that one of the two grooves next to each other among these, that is closer to an electronic device, i.e., to an anode electrode, is formed shallower than the other located on the outside of the one. Then, an insulating material is deposited in the first groove, the second groove and the third groove. The lamination body of the semiconductor substrate and the layers laminated thereon is then diced along dicing lines.

Abstract: Problems with a conventional mesa type semiconductor device, which are deterioration in a withstand voltage and occurrence of a leakage current caused by reduced thickness of an insulation film on an inner wall of a mesa groove corresponding to a PN junction, are solved using an inexpensive material, and a mesa type semiconductor device of high withstand voltage and high reliability is offered together with its manufacturing method. A stable protection film made of a thermal oxide film is formed on the inner wall of the mesa groove in the mesa type semiconductor device to cover and protect the PN junction, and an insulation film having negative electric charges is formed to fill a space in the mesa groove covered with the thermal oxide film so that an electron accumulation layer is not easily formed at an interface between an N? type semiconductor layer and the thermal oxide film.

Abstract: This invention is directed to solving problems with a mesa type semiconductor device, which are deterioration in a withstand voltage and occurrence of a leakage current caused by reduced thickness of a second insulation film on an inner wall of a mesa groove corresponding to a PN junction, and offers a mesa type semiconductor device of high withstand voltage and high reliability and its manufacturing method. After the mesa groove is formed by dry-etching, wet-etching with an etching solution including hydrofluoric acid and nitric acid is further applied to a sidewall of the mesa groove to form an overhang made of the first insulation film above an upper portion of the mesa groove. The overhang serves as a barrier to prevent the second insulation film formed in the mesa groove and on the first insulation film around the mesa groove beyond an area of the overhang from flowing toward a bottom of the mesa groove due to an increased fluidity resulting from a subsequent thermal treatment.

Abstract: An etchant composition contains (a) an alkaline compound mixture of an organic alkaline compound and inorganic alkaline compound and (b) a silicon-containing compound. The organic alkaline compound is composed of one or more ingredients from quaternary ammonium hydroxide and ethylenediamine. The inorganic alkaline compound is composed of one or more ingredients from sodium hydroxide, potassium hydroxide, ammonia and hydrazine. The silicon-containing inorganic compound is composed of one or more ingredients from metal silicon, fumed silica, colloidal silica, silica gel, silica sol, diatomaceous earth, acid clay and activated clay, and the silicon-containing organic compound is composed of one or more ingredients from quaternary ammonium salts of alkyl silicate and quaternary ammonium salts of alkyl silicic acid.

Abstract: A conventional semiconductor device has a problem that, when a vertical PNP transistor as a power semiconductor element is used in a saturation region, a leakage current into a substrate is generated. In a semiconductor device of the present invention, two P type diffusion layers as a collector region are formed around an N type diffusion layer as a base region. One of the P type diffusion layers is formed to have a lower impurity concentration and a narrower diffusion width than the other P type diffusion layer. In this structure, when a vertical PNP transistor is turned on, a region where the former P type diffusion layer is formed mainly serves as a parasite current path. Thus, a parasitic transistor constituted of a substrate, an N type buried layer and a P type buried layer is prevented from turning on, and a leakage current into the substrate is prevented.

Abstract: A mesa type semiconductor device and its manufacturing method are offered to increase a withstand voltage as well as reducing a leakage current. An N?-type semiconductor layer is formed on a surface of a semiconductor substrate, and a P-type semiconductor layer is formed on the N?-type semiconductor layer. After that, a mesa groove is formed by etching the P-type semiconductor layer, a PN junction, the N?-type semiconductor layer and a partial thickness of the semiconductor substrate so that a width of the mesa groove grows from a surface of the P-type semiconductor layer toward the semiconductor substrate. Subsequent wet etching removes a damaged layer in an inner wall of the mesa groove caused by the preceding etching and transforms the mesa groove in a region close to a surface of the P-type semiconductor layer so that a width of the mesa groove increases toward the surface of the P-type semiconductor layer. After that, the semiconductor substrate and the layers stacked on it are diced.

Abstract: The invention provides a mesa semiconductor device and a method of manufacturing the same which minimize the manufacturing cost and prevents contamination and physical damage of the device. An N? type semiconductor layer is formed on a front surface of a semiconductor substrate, and a P type semiconductor layer is formed thereon. An anode electrode is further formed on the P type semiconductor layer so as to be connected to the P type semiconductor layer, and a mesa groove is formed from the front surface of the P type semiconductor layer deeper than the N? type semiconductor layer so as to surround the anode electrode. Then, a second insulation film is formed from inside the mesa groove onto the end portion of the anode electrode. The second insulation film is made of an organic insulator such as polyimide type resin or the like. The lamination body made of the semiconductor substrate and the layers laminated thereon is then diced along a scribe line.

Abstract: The invention provides a mesa semiconductor device and a method of manufacturing the same which enhance the yield and productivity. An N? type semiconductor layer is formed on a front surface of a semiconductor substrate, and a P type semiconductor layer is formed thereon. An anode electrode is further formed on the P type semiconductor layer so as to be connected to the P type semiconductor layer, and a mesa groove is formed from the front surface of the P type semiconductor layer deeper than the N? type semiconductor layer so as to surround the anode electrode. Then, a second insulation film is formed from inside the mesa groove onto the P type semiconductor layer on the outside of the mesa groove. The second insulation film is made of an organic insulator such as polyimide type resin or the like. The lamination body made of the semiconductor substrate and the layers laminated thereon is then diced along a scribe line.

Abstract: A switching control circuit, controlling a transistor, of a voltage generating circuit generating an output voltage of a target level from an input voltage applied to the transistor, comprising: an error amplifier circuit outputting an error voltage obtained by amplifying an error between a voltage according to the output voltage and a first reference voltage; a first comparison circuit comparing the error voltage with a second reference voltage to output a first control voltage; a second comparison circuit comparing the error voltage with a third reference voltage to output first and second voltages a charging and discharging circuit for charging and discharging a capacitor based on the first and second voltages; a third comparison circuit comparing a charged voltage of the capacitor with a fourth reference voltage; and a control circuit outputting a second control voltage for turning off the transistor according to a result of the third comparison circuit.

Abstract: The present invention aims to provide an etching solution composition which enables to etch a metal film in a controllable manner, form a desired definite tapered shape, and obtain a smooth surface without causing etching solution exudation trace. Said problems have been solved by the present invention, which is an etching solution composition for etching metal films containing one or more surfactants selected from the group consisting of alkyl sulfate or perfluoroalkenyl phenyl ether sulfonic acid and the salts thereof.

Abstract: A differential amplifier circuit includes a first transistor in which an electrode on one side is connected to a first constant current source, an electrode on the other side is connected to a second constant current source, and the control electrode is applied with a first input voltage; a second transistor in which an electrode on one side is connected to the first constant current source, an electrode on the other side is connected to a third constant current source, and the control electrode is applied with a second input voltage; and a third transistor in which an electrode on one side is connected to the electrode on the other side of the first or second transistor, the third transistor outputting to an electrode on the other side thereof a current corresponding to a difference between the first and second input voltages.

Abstract: A first switch circuit includes first and second N-type MOSFETs. A second switch circuit includes third and fourth N-type MOSFETs. A control signal is input to a first inverter and a third inverter, the output of the first inverter input to a second inverter and the gate of the fourth MOSFET, the output of the second inverter input to the gate of the first MOSFET, the output of the third inverter input to a fourth inverter and the gate of the third MOSFET, the output of the fourth inverter input to the gate of the second MOSFET. A first input voltage is connected to the source of the second MOSFET and the sources of N-type MOSFETS in the third and fourth inverters. A second input voltage is connected the source of the fourth MOSFET and the sources of N-type MOSFETS in the first and second inverters.

Abstract: A conventional semiconductor device, for example, a lateral PNP transistor has a problem that it is difficult to obtain a desired current-amplification factor while maintaining a breakdown voltage characteristic without increasing the device size. In a semiconductor device, that is a lateral PNP transistor, according to the present invention, an N type epitaxial layer is formed on a P type single crystal silicon substrate. The epitaxial layer is used as a base region. Moreover, molybdenum (Mo) is diffused in the substrate and the epitaxial layer. With this structure, the base current is adjusted, and thereby a desired current-amplification factor (hFE) of the lateral PNP transistor is achieved.

Abstract: A voltage selection circuit is disclosed which comprises: a first through a fourth inverters; a first switch circuit including a first MOSFET of N type and a second MOSFET of N type, respective drains thereof being connected in common; and a second switch circuit including a third MOSFET of N type and a fourth MOSFET of N type, respective drains thereof being connected in common, a common drive voltage being input to the first through fourth inverters, a control signal being input to the first inverter and the third inverter, the output of the first inverter being input to the second inverter and the gate of the fourth MOSFET, the output of the second inverter being input to the gate of the first MOSFET, the output of the third inverter being input to the fourth inverter and the gate of the third MOSFET, the output of the fourth inverter being input to the gate of the second MOSFET, a first input voltage selected depending on the control signal being input to the source of the second MOSFET, a second input vo