Nippon Kogaku K.k.

Junji Hazama

Norio Fujii

Toru Azuma

Kazunari Hada

Atsushi Kawahara

Hisao Izawa

Akikazu Tanimoto

Kinya Kato

Yukio Kakizaki

Kaoru Kikuchi

Kenichi Kodama

Yoichi Hamashima

A method whereby the circuit pattern on a photographic mask or a reticle used in the manufacture of semiconductor devices is inspected for defects by an image processing technique. In this inspection method, the pattern of the mask is printed on a photosensitive member prepared by forming an opaque or semitransparent photosensitive layer on a transparent substrate and an image of the printed pattern formed on the photosensitive member is inspected by the image processing technique.

Method of inspecting the pattern on a photographic mask

An apparatus for optically measuring the very small gap between a reference plane and a substrate parallel to the reference plane. A beam of energy converging on the reference plane is reflected by the substrate and a spot of reflected beam is formed on a detecting plane at a different position. An array of detecting elements for detecting the size of the spot on the detecting plane is adjusted in position in such a manner that the center of the spot coincides with the center of any one of the detecting elements, thereby preventing any error of the in-focus detecting position due to the deviation between the center of the spot and the center of the detecting element.

Small gap measuring apparatus

An alignment apparatus for aligning a semiconductor wafer with an optical mask containing a circuit pattern to be exposed onto the wafer in the fabrication of semiconductor devices by a proximity exposure apparatus. The alignment apparatus includes light beam radiating means for radiating a first and second light beams which are imaged at positions separated by a given gap in a direction substantially perpendicular to two flat sheets, first and second detecting means for respectively detecting the imaging condition of the first and second light beams at the flat sheets, means for relatively moving the light beam radiating means and the flat sheets, and means for discriminating the order of generation of signals from the first and second detecting means, whereby the value of each gap between the selected areas of the two flat sheets at a plurality of places is detected with a high degree of accuracy without changing the gap between the flat sheets thereby making it possible to correct the parallelism, inclination, etc., of the flat sheets.

Apparatus for aligning mask and wafer used in semiconductor circuit

An apparatus for inspecting a pattern consisting of light and dark areas formed on a planar test specimen according to design information, comprising: an imaging device for viewing the pattern to generate image information; a detector for generating a first signal upon detection that, in response to the image information, a boundary line between the light and dark areas of the pattern is bent in a determined stepping form in the direction of the plane; a memory for generating and storing a second signal, upon detection that the boundary line of the pattern has a bend of stepping form according to the design information, corresponding to the position in the imaging area of the bend in the design information; and an inspecting device for discriminating, upon generation of the first signal, the presence or absence of the second signal in the memory corresponding to the position of the first signal in the image area.

Apparatus for detecting defects in pattern

An apparatus for the attitude control of a plate-form body such as mask or wafer comprises a supporting table, a first movable stage placed on the table and a second movable stage placed on the first stage. The second movable stage is provided means for holding the plate-form body on a reference plane containing the origin of the coordinates defined by two orthogonal coordinate axes. Between the supporting table and the first movable stage there is disposed first driving means. The first driving means is disposed for displacing the first movable stage at at least two positions opposed to each other relative to one of the coordinate axes. The displacement is produced in the direction substantially normal to a segment passing through the origin of the coordinates and forming a determined angle with the reference plane. The displacement of the first stage relative to the table in the direction substantially normal to the above direction is inhibited by first limiting means. Similarly second driving means is disposed between the first and second movable stages for producing the displacement of the second stage at at least two positions opposed to each other relative to the other coordinate axis. The displacement produced by second driving means is in the direction substantially normal to a segment passing through the origin of the coordinates and forming a determined angle with the reference plane. Second limiting means is provided to inhibit the displacement of the second movable stage in the direction substantially normal to the above direction of displacement by the second driving means.

Apparatus for the attitude control of plate-form body

Two-dimensional pattern detecting apparatus provided with register for serially receiving binary signals obtained from analog signals of a two-dimensional pattern and adapted to divide the pattern into pixels and to represent the density of bright and dark for pixels by the binary signals. The apparatus further includes a processing circuit adapted to compare with predetermined patterns a pattern composed of 8 peripheral pixels of a partial area of 3.times.3 pixels within the two-dimensional pattern, on the basis of the binary signals stored in the register. The processing circuit outputs a binary signal of a logic value stored in said register corresponding to a central pixel of the partial area when the pattern of the 8 pixels coincides with one of said predetermined patterns, and to outputs a binary signal of a logic value prevailing in 8 binary signals stored in the register corresponding to the 8 pixels when the pattern of the 8 pixels does not coincide with any of the predetermined patterns.

Apparatus for detecting two-dimensional pattern and method for

A pattern examining in which a pattern on an examined object such as reticle or mask is scanned to produce image binary signals of picture elements; binary information corresponding to a local area on the examined object is serially extracted from the image binary signals; and shape detection is effected for detecting by means of the binary information whether or not the pattern in the local area possesses a determined geometric shape or characteristics. The result of the shape detection is compared with the information on design relating to the geometric shape or characteristics which the pattern on the examined object should possess.

Apparatus for detecting the defect of pattern

A pattern defect testing apparatus comprises a first detection circuit which defines a first detection area on a two-dimensional pattern and produces a first detection signal when all digital signals representative of densities of picture cells in the first detection area have the same logical value, a second detection circuit which defines a second detection area on the two-dimensional pattern and produces a second detection signal when at least one of digital signals representative of densities of picture cells in the second detection area has a logical value different from that of the digital signals to the first detection circuit, and a discriminating circuit for discriminating the presence of a defect in the second detection area when the first and second detection signals are produced.

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Kawasaki, Japan

Junji Hazama