Mitsubishi Denki Kabushiki Kaisha

Hitoshi Tanaka

Toshimasa Tomoda

Nobuyuki Kosaka

Yoko Miyazaki

Toyomi Ohshige

Noboru Mikami

Masahiko Sakamoto

Hiroshi Mitsuda

Masao Koshinaka

Minoru Akiyama

Yoshinori Ito

Yoko Yamamoto

A code reading pattern and an image pickup apparatus are provided for reading a symbol representing significant information, the symbol encoded by the pattern. The code reading pattern is formed by repeated markings of constant pitch on the surface of an object. The markings define area having at least one boundary, the at least one boundary defining an outline of the symbol. The apparatus includes a lighting system for illuminating the code reading pattern with parallel light, an imaging system for imaging light reflected from the pattern, a spatial frequency filtering system, located at the near back focal plane of the imaging system, for blocking regular reflected light and for transmiting diffracted light to project an image of the symbol, and a receiver for receiving the image.

Code reading pattern and an image pickup apparatus for reading the

A spatial frequency filter used in a pattern defect detection device, including a pattern which includes a black spot having a diameter expanded by a controlled amount in comparison with the diameter of a black spot on a photosensitive plate obtained by exposure by diffracted light from a pattern on a model specimen.

Method of manufacturing a spatial frequency filter for use in a pattern

A spatial frequency filter used in a pattern defect detection device, including a pattern which includes a black spot having a diameter expanded by a controlled amount in comparison with the diameter of a black spot on a photosensitive plate obtained by exposure by diffracted light from a pattern on a model specimen

Pattern defect detection device and a spatial frequency filter used

An inspection device for detecting defects in a periodic pattern on a semiconductor wafer includes a laser oscillator. In the exposure process, light emitted from the laser oscillator is divided into a subject beam and a reference beam. The subject beam is guided to a semiconductor wafer having a periodic pattern thereon by mirrors and a beam expander. The light scattered from the specimen is collected by a lens on a photographic plate. The reference beam is guided to the photographic plate via a second beam expander and another mirror. The intensity of the reference beam is adjusted to a level at which the reference beams interferes on the photographic plate with the light scattered from defects in the periodic pattern and collected by the lens. Thus, a hologram of the defects in the pattern is recorded on the photographic plate. After development, the photographic plate is returned to its original position and used to form a holographic image of the defects with a transmitted regeneration light beam.

Inspection device for detecting defects in a periodic pattern on a

A fine-particle measuring apparatus designed to measure fine particles attached to the surface of a substrate for a semiconductor device set in a processing unit for formation of films, etching, cleaning, etc. and fine particles suspended in the space above the substrate surface by the use of scattering of a laser beam caused by these fine particles. The measuring apparatus comprises a laser beam scanning mechanism for irradiating a measuring space with a laser beam the angular position of which is minutely modulated at a predetermined frequency, a photodetector which receives light scattered by a fine particle and converts the received light into an electrical signal, and a signal processor which extracts from the electrical signal output by the photodetector a signal component whose frequency is the same as or double that of a modulating signal for the minute scanning with the laser beam and which has a constant phase difference in terms of time with respect to the modulating signal. Thus, it is possible to measure fine particles with high sensitivity without substantially disturbing the environment inside the process unit or the process itself.

System for detecting minute particles on or above a substrate

A pattern defect detecting system for an integrated semiconductor circuit or the like, utilizing the phenomenon that in the case of a test pattern having regularity, the intensity of diffracted light appearing on a back-focal plane of a lens is high, while defects or foreign matters not having regularity are low in the intensity of diffracted light. As a concrete example, an optical space modulator is used to record only an intense light portion in real time. The recorded diffraction pattern can be erased easily by, for example, application of voltage and radiation of light. A spatial filter can be prepared in real time in 1:1 correspondence to a test sample. Besides, even in the case of change of test pattern, an immediate action can be taken for continuous detection of defects, thus permitting test on-line.

System for detecting defects in a regularly arranged pattern such as an

A numerically controlled machining system which stores in a memory, a machining program having machining pattern commands for specifying machining patterns, tool commands for specifying tools, and positional information commands for specifying positional information for the tools. A selecting device selects only the tool commands from the stored machining program, and displays parameters regarding the tools selected by the selecting device. The display can display a list of tools along with the parameters thereof so that the operator can locate the tools with utmost ease for tool preparation and attachment.

Growing community of inventors

Hyogo, Japan

Hitoshi Tanaka