Hitachi, Ltd.

Akihiro Takanashi

Toshiei Kurosaki

Sumio Hosaka

Shinji Kuniyoshi

Yoshio Kawamura

Tsuneo Terasawa

Tatsuo Harada

Junichi Kobayashi

Tetsuya Tanaka

Takahiro Daikoku

Yutaka Watanabe

Shigeo Moriyama

Toshio Hatada

Shizuo Zushi

Takayuki Atarashi

Norikazu Hashimoto

Hisashi Maejima

Shuji Sugiyama

Masamoto Akeyama

Seiya Hashimoto

Yataro Kondo

A highly reliable electronic apparatus free from condensation in the cabinet of the apparatus. The electronic apparatus has printed circuit boards on which heat emitting semiconductor devices are mounted and a fan. The electronic apparatus further comprises a hygrometer for measuring the relative humidity and dew-point temperature of the cooling air that is introduced into the cabinet through an opening, a surface temperature sensor for sensing the temperature of the surface of the semiconductor devices, an internal temperature sensor for sensing the internal temperature of the semiconductor device, dehumidifier and heater means made up of a heat pump and an outdoor unit, and a controller for controlling the dehumidifier means and the heater means so that the relative humidity is less than 100% and the dew-point temperature is less than the surface temperature of the semiconductor devices.

Air-cooled electronic apparatus with condensation prevention

A pattern detector for precise position measurement of a wafer, used in a mask aligner used in manufacturing a semiconductor device is disclosed. A positioning pattern on the wafer is magnified and projected by a magnifying optical system and the magnified projected image is precisely detected to determine a position of the positioning pattern. As a light to form the magnified projected image, plurality of monochromatic lights of different wavelengths are available through optical filters and the magnifying optical systems are arranged one for each of the monochromatic lights. By selecting one of the optical filters, the magnified projected image of the positioning pattern is formed by the monochromatic light having an optimum wavelength to the wafer and the precise position of the positioning pattern on the wafer can be detected.

Pattern detector

A pattern detector according to the present invention adopts a processing method wherein means is provided anew with which the intensity distribution of light reflected from or transmitted through an illuminated specimen is photoelectrically converted, and a pattern position is detected at high speed from the ratio between the primary moment and integral value of a detection signal thus derived, whereupon a symmetry calculation is executed within a narrow range around the detected value, whereby the pattern position is found fast and precisely.

A pattern generator in which a workpiece to be machined into a desired pattern shape is held in vacuum and is irradiated with a laser beam condensed to be fine, while scanning the laser beam so as to depict the desired pattern shape, whereby the workpiece is directly machined in conformity with the desired pattern shape. As the workpiece, one in which a shading film (for example, chromium film) is deposited on a transparent glass substrate is employed, and it is irradiated with the laser beam in the vacuum, whereby the irradiated parts of the shading film are vaporized to fabricate a shading mask pattern of good quality.

Pattern generator

There is disclosed a pattern forming apparatus for projecting a pattern which is formed on a reticle upon a photoresist layer on a substrate which comprises an illumination system for illuminating the pattern for forming an optical image, a reduction lenses for reducing the optical pattern image at a certain reduction ratio and projecting the reduced optical pattern image upon the photoresist layer formed on the substrate for exposing the photoresist layer, and liquid sustaining means for filling a gap between at least a portion of the reduction lenses and the photoresist layer with an optically transparent liquid having a refractive index of more than 1 (one).

Pattern forming apparatus

An automatic focusing apparatus according to the present invention is constructed of a base on which a substrate is placed, detection means for detecting a pressure of air which is caused to flow out of an interspace between the substrate and an orifice by spurting the air from the orifice toward the substrate, reference pressure generation means for generating a reference pressure which is necessary for setting a standard distance between the substrate and the orifice, a pressure transducer which receives pressure signals from said detection means and said reference pressure generation means and which converts a pressure difference between these pressure signals into an electric signal, base drive means for moving the substrate in parallel with the orifice on the basis of the output signal from said pressure transducer, and offset signal generation means for generating a signal which, when superposed on the output signal from said pressure transducer, serves to shift the substrate from the standard distance.

Automatic focusing apparatus

A pattern exposing apparatus comprising means for projecting a semiconductor device mask pattern onto the photoresist layer coated on a semiconductor substrate, and means for projecting an identification mark which is specific to each substrate onto a part of the photoresist layer.

Pattern exposing apparatus

A laser beam scanning system for focusing a laser beam to a fine spot and for scanning precisely a large field includes an acousto-optical deflector enabled to deflect a laser beam in the direction of one axis or in the directions of two axes, while maintaining the fine spot diameter, to scan a small field, a relay lens for projecting said deflection point to the center of an objective lens, to effect the focusing of the beam to a fine spot, a high speed carriage enabled to move with high accuracy in biaxial directions, a precise position detector enabled to detect the position of the carriage, and a controller for organically controlling the aforementioned respective functions thereby to make it possible to precisely deflect the laser beam over a large field, whereby a scanning operation of a large field at a high speed and with a high accuracy is performed by the laser beam.

Laser beam scanning system

A pattern detecting apparatus is disclosed which comprises, in order to detect the center of a positioning pattern on a sample with high accuracy in a wide range, means for illuminating the positioning pattern, means for defining an illumination range in which the positioning pattern is illuminated, means for focusing reflected light from the positioning pattern on a predetermined image plane, means for electrically detecting a bright and dark image on the image plane in accordance with positions on the image plane, means for removing a signal corresponding to the outside of the illumination range from the output signal of the detecting means and for holding, in place of the removed signal, a level of the output signal produced within the illumination range, and means for detecting a position of the center of the positioning pattern from the output signal of the holding means.

Pattern detecting apparatus

In a reduction projection aligner system wherein a pattern on a reticle is formed directly on a wafer by reducing, projecting and printing it, a positioning pattern on the wafer is optically magnified and projected and then focused onto a focal plane where a slit scans the projected image. The distance from a mechanical origin provided on the supporting body of the system to the positioning pattern on the wafer is then measured on the basis of the movement of the slit, and the reticle is then relatively moved and positioned so as to coincide with the position of the wafer relative to the body of the system, thereby bringing the wafer and the reticle into coincidence.

Reduction projection aligner system

A proportional linear output system in which a second link mechanism consisting of a link and a slider is coupled to a portion of a link of a first link mechanism consisting of a link and a slider, so that the individual link mechanisms describe geometrically similar figures, and in which an input displacement fed to one slider is converted into an output displacement and is produced by another slider, the quantity of output displacement being reduced according to a ratio of similar figures of the first link mechanism to the second link mechanism.

Proportional linear output system

An improved optical exposure apparatus for use in exposing a workpiece to a desired light pattern with a high alignment accuracy and a high operational speed is disclosed. The apparatus comprises a moving table on which a workpiece to be exposed is disposed, a movable holder on which a mask having an original pattern is disposed, a light source for irradiating said mask, a reduction lens for projecting a reduced pattern of said original pattern onto said workpiece, means for positioning said moving table to a predetermined position, means for detecting the error of said table positioning, means for calculating a value of the error of positioning the workpiece divided by the reduction rate of the reduction lens, and means for automatically shifting said movable holder by the calculated value so as to cancel said error.

Growing community of inventors

Kokubunji, Japan

Akihiro Takanashi