Abstract:
A pin diode is formed by a p+ collector region, an n type buffer region, an n− region and an n+ cathode region. A trench is formed from the surface of n+ cathode region through n+ cathode region to reach n− region. An insulating film is formed along an inner wall surface of trench. A gate electrode layer is formed to oppose to the sidewall of n+ cathode region with insulating film interposed. A cathode electrode is formed to be electrically connected to n+ cathode region. An anode electrode is formed to be electrically connected to p+ collector region. The n+ cathode region is formed entirely over the surface between trenches extending parallel to each other. Thus, a power semiconductor device in which gate control circuit is simplified and which has good on property can be obtained.
Abstract:
The present invention is to provide a photomask which has a sufficient durability to short-wavelength exposure beams, too, and also can prevent any foreign matter from adhering to patterns for transfer. In a photomask on which a transfer pattern to be transferred to an exposure-target substrate 19 is formed and through which a stated exposure beam applied to a pattern surface 1P where the transfer pattern is formed is guided to a projection optical system PL for forming an image of the pattern, the photomask comprises a transmitting plate 3 disposed apart from the pattern surface by a stated interval d0 and having a stated thickness h and a transmission to the exposure beam, and the transmitting plate is substantially square and fulfills a stated condition.
Abstract:
Optical exposure apparatus and methods of using same, for patterning a workpiece and photo-cleaning the optical components in the apparatus, which can be contaminated by moisture and organic compounds in the atmosphere. The apparatus comprises an illumination optical system having a light source and one or more optical components, and a projection lens having an object plane and an image plane and one or more optical components. The optical exposure apparatus includes an exposure optical path or an exposure light beam through a predetermined space in the optical exposure system. An optical path deflection member for deflecting light is introduced into the exposure optical path so as to create a second optical path that differs from the exposure optical path. Also disclosed is a method of photo-cleaning the aforementioned optical components, including the steps of forming an exposure optical path and then changing this path to create a second optical path that differs from the exposure optical path. An additional method of photo-cleaning a projection lens is disclosed, including the steps of providing an illumination light beam along an optical axis, providing and inserting a photo-cleaning optical member having refractive power into the beam, and refracting the beam so as to illuminate the lens surfaces comprising the projection lens.
Abstract:
Alignment is carried out between a mask and a wafer even during exposure as occasion demands, according to the movement of a pattern image caused by the positional fluctuation of a reflecting member. An exposure apparatus includes detection systems (13) and (14) for detecting the fluctuation amounts of reflecting members (M1) and (M2) from a reference position, and an arithmetic system (15) adapted to compute an amount of correction based on the detected fluctuation amounts, the amount of correction regarding at least one of the mask and the photosensitive substrate (4), and being necessary for substantial alignment between the pattern image formed in a moved state from a reference image-forming position and the photosensitive substrate (4). Based on the computed amount of correction, at least one of the mask and the photosensitive substrate is moved.
Abstract:
A method and illumination optical system forms a modified illumination configuration on an optical integrator so that a secondary light source having a desired modified illumination configuration is formed and light loss is minimized. A light beam shape changing element that diffuses illumination in a plurality of directions, and an angular light beam forming element that forms a plurality of light source images operate together to create a modified illumination configuration on the optical integrator. Since the secondary light source has a desired modified illumination configuration, an aperture stop used to restrict the size and/or shape of the secondary light source blocks only a small amount of illumination, or can be eliminated altogether. It is possible to alter the annular ratio and outer diameter of an annular or quadrupole modified illumination configuration by changing the magnification of a zoom optical system positioned between the light beam shape changing element and the angular light beam forming element. Furthermore, by changing the focal length of a zoom optical system (which is positioned upstream of the optical integrator), it is possible to change the outer diameter of the annular or quadrupole secondary light source without changing the annular ratio thereof.
Abstract:
Optical exposure apparatus and methods of using same, for patterning a workpiece and photo-cleaning the optical components in the apparatus, which can be contaminated by moisture and organic compounds in the atmosphere. The apparatus comprises an illumination optical system having a light source and one or more optical components, and a projection lens having an object plane and an image plane and one or more optical components. The optical exposure apparatus includes an exposure optical path or an exposure light beam through a predetermined space in the optical exposure system. An optical path deflection member for deflecting light is introduced into the exposure optical path so as to create a second optical path that differs from the exposure optical path. Also disclosed is a method of photo-cleaning the aforementioned optical components, including the steps of forming an exposure optical path and then changing this path to create a second optical path that differs from the exposure optical path. An additional method of photo-cleaning a projection lens is disclosed, including the steps of providing an illumination light beam along an optical axis, providing and inserting a photo-cleaning optical member having refractive power into the beam, and refracting the beam so as to illuminate the lens surfaces comprising the projection lens.
Abstract:
An exposure apparatus for transferring a pattern on a mask (M) onto a photosensitive substrate (W) via a projection-optical system can reduce gas fluctuation even if the length of the optical path through gas is relatively long, and even if the diameter of light flux through the gas is relatively large.The projection-optical system satisfies the condition ##EQU1## where .lambda. is a wavelength of exposure light used in the apparatus, .SIGMA.i is a summary of gas sections i in an optical path from the mask to the photosensitive substrate, Li is a length of a gas section i along the optical axis, in m, and Ri is an average of a mask-side diameter and a substrate-side diameter of a light flux in each gas section, the light flux emerging from a maximum image height and advancing within meridional plane, wherein at least one gas section i is filled with helium or neon.
Abstract:
Electronic component packaging case comprising a substantially plate-like body having a substantially spiral passageway formed in its interior, a linear passageway formed therein as a continuation of an outermost circular portion of the sapiral passageway, an outlet formed therein as a continuation of the linear passageway to communicate with the exterior of the body, a plurality of electronic components received in a row in the spiral passageway, and a plurality of air-intakes for facilitating forwarding of the electronic components along the spiral passageway to the outlet, the air-intakes being formed in the casing body in a manner to communicate between respective circular portions of the spiral passageway and the exterior of the casing body, the case being adapted to be supported on a base of an electronic component supply mechanism with the body standing on the base when the case is used as an electronic component supply source, the outlet being formed at a portion of the casing body which is located at an upper position when the case is supported on the base, the outlet being faced upward, above which outlet the mounting head is adapted to wait. Also, an electronic component supply mechanism for and a method of supplying electronic components to the mounting head by using the packaging case are disclosed.
Abstract:
A screen printing method includes the steps of moving a doctor plate across a printing screen to apply a paste thereon and then moving a squeegee across the screen to deposit a paste on an object below the screen while maintaining a predetermined pressure of the screen against the object to produce a substantially even deposition of the paste. The method also can include varying the squeegee pressure as the screen tension varies to maintain the predetermined printing pressure and using a screen aligning mark on an imaging plane to correct the positional relationship between the screen and the object.