Abstract: A formation method of an element isolation film according to which a high-voltage transistor with an excellent characteristic can be formed is provided. On a substrate, a gate oxide film is previously formed. A CMP stopper film is formed thereon, and thereafter, a gate oxide film and a CMP stopper film are etched. The semiconductor substrate is etched to form a trench. Further, before the trench is filled with a field insulating film, a liner insulating film is formed at a trench interior wall, and a concave portion at the side surface of the gate oxide film under the CMP stopper film is filled with the liner insulating film. In this manner, formation of void in the element isolation film laterally positioned with respect to the gate oxide film can be prevented.

Abstract: A formation method of an element isolation film according to which a high-voltage transistor with an excellent characteristic can be formed is provided. On a substrate, a gate oxide film is previously formed. A CMP stopper film is formed thereon, and thereafter, a gate oxide film and a CMP stopper film are etched. The semiconductor substrate is etched to form a trench. Further, before the trench is filled with a field insulating film, a liner insulating film is formed at a trench interior wall, and a concave portion at the side surface of the gate oxide film under the CMP stopper film is filled with the liner insulating film. In this manner, formation of void in the element isolation film laterally positioned with respect to the gate oxide film can be prevented.

Abstract: A formation method of an element isolation film according to which a high-voltage transistor with an excellent characteristic can be formed is provided. On a substrate, a gate oxide film is previously formed. A CMP stopper film is formed thereon, and thereafter, a gate oxide film and a CMP stopper film are etched. The semiconductor substrate is etched to form a trench. Further, before the trench is filled with a field insulating film, an liner insulating film is formed at a trench interior wall, and a concave portion at the side surface of the gate oxide film under the CMP stopper film is filled with the liner insulating film. In this manner, formation of void in the element isolation film laterally positioned with respect to the gate oxide film can be prevented.

Abstract: The present invention provides a semiconductor device including:a semiconductor substrate of a first conductive type; a first well region of the first conductive type formed in the semiconductor substrate; an epitaxial region of a second conductive type formed in the semiconductor substrate and arranged in a region adjacent to the first well region; a buried region of the second conductive type that is formed in a region at a lower part of the epitaxial region and that has an impurity concentration higher than that of the epitaxial region; a trench formed at boundaries between the first well region and the epitaxial region, and between the first well region and the buried region; a first semiconductor element that is formed on the first well; and a second semiconductor element that is formed on the epitaxial region.

Abstract: The present invention provides a manufacturing method of a semiconductor device including: a step of forming a shallow trench on a semiconductor substrate; a step of forming an insulating layer in the shallow trench; and a step of forming a deep trench in the shallow trench, the deep trench penetrating through the insulating layer and being deeper than the shallow trench; wherein the step of forming the deep trench includes to form a first deep trench including an inner side face having a first taper angle with respect to the semiconductor substrate; and form a second deep trench including an inner side face having a second taper angle with respect to the semiconductor substrate, wherein the second taper angle is different from the first taper angle.

Abstract: A formation method of an element isolation film according to which a high-voltage transistor with an excellent characteristic can be formed is provided. On a substrate, a gate oxide film is previously formed. A CMP stopper film is formed thereon, and thereafter, a gate oxide film and a CMP stopper film are etched. The semiconductor substrate is etched to form a trench. Further, before the trench is filled with a field insulating film, an liner insulating film is formed at a trench interior wall, and a concave portion at the side surface of the gate oxide film under the CMP stopper film is filled with the liner insulating film. In this manner, formation of void in the element isolation film laterally positioned with respect to the gate oxide film can be prevented.

Abstract: A method for manufacturing a semiconductor device comprising: a first step of successively forming a silicon oxide film and a silicon nitride film on a silicon substrate, followed by forming a silicon nitride oxide film or a multilayered film containing the silicon nitride oxide film on the silicon nitride film; a second step of forming a photoresist film having an opening portion located at the position corresponding to an element isolation area of the silicon substrate on the silicon nitride film or the multilayered film according to a photolithography method; a third step of forming a trench having a pair of tapered side surface portions on the confronting side surfaces thereof on the silicon nitride oxide film or the multilayered film by using the photoresist film as a mask, the tapered side surface portions being inclined toward the substrate side so as to approach each other; and a fourth step of patterning the silicon nitride film and the silicon oxide film by dry etching by using the photoresist fi

Abstract: A method for manufacturing a semiconductor device comprising: a first step of successively forming a silicon oxide film and a silicon nitride film on a silicon substrate, followed by forming a silicon nitride oxide film or a multilayered film containing the silicon nitride oxide film on the silicon nitride film; a second step of forming a photoresist film having an opening portion located at the position corresponding to an element isolation area of the silicon substrate on the silicon nitride film or the multilayered film according to a photolithography method; a third step of forming a trench having a pair of tapered side surface portions on the confronting side surfaces thereof on the silicon nitride oxide film or the multilayered film by using the photoresist film as a mask, the tapered side surface portions being inclined toward the substrate side so as to approach each other; and a fourth step of patterning the silicon nitride film and the silicon oxide film by dry etching by using the photoresist film

Abstract: An expansion shaft includes a first and a second shaft section aligned on the same axis. The second shaft section is inserted in a fit hole of the first shaft section while both the shaft sections are interconnected via a spline or serration. A resilient member is provided which possesses a single snap ring of C-shape fitted on a thin shaft portion of the second shaft section. An arm is axially extended from the snap ring. The arm resiliently presses against an inner circumferential surface of the fit hole for preventing the shaft sections from radially vibrating relative to each other.

Abstract: An expansion shaft includes a first and a second shaft section aligned on the same axis. The second shaft section is inserted in a fit hole of the first shaft section while both the shaft sections are interconnected via a spline or serration. A resilient member is provided which possesses a single snap ring of C-shape fitted on a thin shaft portion of the second shaft section. An arm is axially extended from the snap ring. The arm resiliently presses against an inner circumferential surface of the fit hole for preventing the shaft sections from radially vibrating relative to each other.

Abstract: A method for cutting a surface of a base of a photoreceptor for electrophotography is disclosed. The method comprises steps of:(a) supplying an aqueous cutting fluid to the surface of the photoreceptor base;(b) cutting the surface of the photoreceptor base by a cutting tool comprising a single crystal diamond.

Abstract: A cutting apparatus for finishing a surface of a substrate of a photoreceptor drum of an image forming apparatus estimates a finish state of the surface on real time with the finishing. The cutting apparatus has a detector to detect a cutting force to a cutting tool from the surface in finishing, a memory to store a cutting force pattern to distinguish the finish state of the surface, comparator means to compare the detected cutting force with the stored cutting force pattern and judging means to judge the finish state of the surface along with the progress of the cutting process.

Abstract: A polygon mirror is produced using a diamond tool. The diamond tool includes a major cutting edge and an end cutting edge. The major cutting edge is formed straight by a rake face and a side flank, the major cutting edge having a first side and a second side. The end cutting edge is formed straight by the rake face and a front flank, the end cutting edge having a third side. A microscopic cutting edge is arranged between the second side and the third side so that the major cutting edge and the microscopic cutting edge together create a first corner at the second side, and the end cutting edge and the microscopic cutting edge create a second corner at the third side. The rake face is inclined downward from the second corner to the first side. The microscopic cutting edge is between 0.1 mm and 0.4 mm in a direction of the end cutting edge. The microscopic cutting edge at the first corner is swept back by an amount between 0.21 .mu.m and 0.6 .mu.

Abstract: In machining a substrate surface of a photoreceptor by the use of a cutting machine which supplies cutting lubricant from a reservoir to a cutting tool of the cutting machine, the method comprises a measurement of a cutting tool temperature by a sensor and a control of both the temperature of cutting lubricant and a flow rate thereof. The control is responsive to the cutting tool temperature and suppresses a temperature fluctuation of the cutting tool.

Abstract: A method of surface-processing a photoreceptor base including aluminum material for electrophotography on a lathe, in which a surface of the base is cut by a cutting tool having a sintered polycrystalline diamond body while cutting fluid, composed of water, an aqueous solution of a surface-active agent or an aqueous solution of a water-soluble organic solvent, is being supplied to the surface of the base frame.

Abstract: In a method of manufacturing a photoreceptor base drum by a lathe-turning machine in which a cutting tool is brought in contact with a surface of the base drum and travels in the axial direction to finish the surface of the base drum into a mirror-like surface, a main cutting edge formed by a rake surface and a front flank surface on the cutting tool is shaped as a curved surface with a radius of curvature of 0.15 to 3.5 .mu.m, and the rake surface and the front flank surface are shaped to smoothly continue to the curved surface of the main cutting edge.

Abstract: An air supply control system for an internal combustion engine comprises at least first and second turbosupercharger, an exhaust cutoff valve operative selectively to open and close an exhaust passage in which a turbine of the second turbosupercharger is disposed, an intake air cutoff valve operative selectively to open and close an intake passage in which a blower of the second turbosupercharger is disposed, a cutoff valve controller operative to control the exhaust cutoff valve and the intake air cutoff valve so as to cause the first turbosupercharger to work when intake air mass flow fed to the engine is to be relatively small and to cause both of the first and second turbosuperchargers to work when intake air mass flow fed to the engine is to be relatively large, an engine operation detector, and an operation controller operative to vary, in response to an engine operating condition detected by the engine operation detector, a boundary between first and second operating areas provided on an operating char

Abstract: A toner collecting device for collecting residual toner removed from an image retainer by a cleaning device after a toner image formed in the image retainer has been transferred to a sheet of paper. The toner collecting device has therein a conveyor device for carrying the residual toner. The conveyor device has its leading end portion disposed at a central portion of the toner collecting device. The upper surface of the toner collecting device has functions to guide transfer paper and to support a transfer electrode, and the leading end portion of the conveyor device is provided with a toner distributing diffusion blade member.

Abstract: A toner collecting device for collecting residual toner removed from an image retainer by a cleaning device after a toner image formed on the image retainer has been transferred to a sheet of paper. The toner collecting device has therein a conveyor device for carrying the residual toner. The conveyor device has its leading end portion disposed at a central portion of the toner collecting device. The upper surface of the toner collecting device has functions to guide transfer paper and to support a transfer electrode, and the leading end portion of the conveyor device is provided with a toner distributing diffusion blade member.

Abstract: A recording apparatus wherein a bottom of a body of the apparatus having conveyor device for conveying recording paper is freely opened and closed to open the conveyor device when the body is lifted up. A body frame composed of a front panel, a rear panel and a bottom plate of the recording apparatus is molded by a resin as a unit.