Matsushita Electric Industrial Co., Ltd.

Matsushita Electrical Industrial Co., Ltd.

Takeo Sato

Masaki Yamamoto

Shinichiro Aoki

Nobuhiro Araki

Noboru Nomura

Hiroyuki Takeuchi

Koichi Kawata

Yoshiyuki Sugiyama

Keisuke Koga

Yoshito Nakanishi

Shinichi Mizuguchi

Hiroyuki Nagano

Katsumasa Yamaguchi

Shotaro Yoshida

Takashi Inoue

Tatsuo Itoh

Hiroshi Yamashita

Masaki Suzuki

Keishi Kubo

Toshiyuki Watanabe

Kazuhiro Yamashita

Nobuaki Furuya

Noriaki Yukawa

Takeo Miyata

Tadashi Kaneko

Satoru Kimura

Keiji Fujita

Atsushi Ueno

Toshiyuki Iwazawa

Atushi Ueno

Yoshihito Nakanishi

Hisato Matsushita

The present invention provides spot-illumination of a specific size having sufficiently homogeneous light intensity distribution, with a small and inexpensive apparatus. A lighting assembly condenses the light from light source 1 with condensing-reflecting member 2. An optical integrator 3 receives at its one end the light via condensing-reflecting member 2 and emits from the other end after making the light intensity distribution homogeneous A projection lens system 4 projects the emitting surface of optical integrator 3 onto an emitted surface. By shifting the relative positioning between the lighting assembly and the substrate 11, and adjusting the distance between the substrate 11 and the mask 12, which stores a pattern to be formed, a specified area of the exposure surface 11a is scanned and exposed to have a mask pattern transcribed on the exposure surface 11a.

Lighting assembly, exposure apparatus and exposure method employing the

A focus position detecting method includes: obtaining quantized two-dimensional image data including an object to be in focus with respect to an optical system by imaging the object through the optical system, defining a specified area in the two-dimensional image data; defining a partial image in the specified area, the partial image being composed of a target pixel and peripheral pixels on a line in a specified direction in which the target pixel exists; defining a left area and a right area respectively positioned on left and right sides of the target pixel on the line in the specified direction; calculating gray-level data of each pixel in the left area; calculating gray-level data of each pixel in the right area; obtaining as a gray-level ratio a ratio of calculation result of the left area to calculation result of the right area; calculating an evaluation function by means of the gray-level ratio by repeating the gray-level ratio calculating step in the specified area; obtaining a plurality of evaluation function calculation values in a variety of optical positions by repeating the steps for calculating the gray-level data of the left and right areas, obtaining the gray-level ratio, and calculating the evaluation function through variation of the optical position of the object, and obtaining a focus position of the object with respect to the optical system based on the evaluation function calculation values.

Method of detecting focus position of object from variable gray level

A position signal producing apparatus, for an apparatus for project-printing a pattern on a reticle onto a wafer through a project lens system with exposure light, for producing a position signal indicative of the position of the wafer is disclosed, wherein two different frequency components of alignment light whose frequencies are different from that of the exposure light are interfered with each other at a position alignment blank to form interference fringes having a given pitch. The interference fringes are projected onto a diffraction grating through an achromatizing optical system and the project lens system. Diffracted light returning from the diffraction grating is received by a photodetector which provides a light beat signal. A position deviation signal obtained by phase comparison of the light beat signal provides position alignment by controlling relative positions between the position alignment blank and the diffraction grating. Two light beams of the two different frequency components split by a polarized beam splitter are equalized in image converting condition, or image aspect, by a mirror, so that an accurate mixing of the two frequency components of light beams is performed at the position alignment blank.

Reflective alignment position signal producing apparatus

An exposure system includes a pulse light source emitting light in response to a trigger signal and giving a predetermined exposure light quantity by a plurality of times of light emission. A reticle has an alignment mark and a light exposure pattern. A projection lens contractedly projects the pattern of the reticle. A wafer has an alignment mark to be located. The wafer is exposed to a projection of the pattern. A wafer stage is movable and carries the wafer. A laser interferometer measures a position of the wafer stage. An alignment device serves to detect a condition of an alignment of the wafer with respect to the reticle in an exposure position.

Exposure system

A reticle/wafer alignment system provided with a laser beam source for emitting laser beams, a first optical system portion for a reticle/wafer alignment which consists of a first optical sub-system for receiving laser beams from the laser beam source and projecting the received laser beams onto alignment marks formed on a substrate and made up of diffraction gratings and a second optical sub-system for gathering laser beams diffracted by the alignment marks to form an image thereof, a photoelectric detection portion for performing a photoelectric conversion of the gathered laser beams, a position detecting portion for measuring the position of the substrate based on a signal outputted from the photoelectric detection portion, a second optical system portion for an image processing which consists of a third optical sub-system for illuminating the alignment marks and a fourth optical sub-system having a television camera for observing the image of the alignment marks, and an image processing portion for performing an image processing of video signals outputted from the television camera. The first and second optical system portions are made in such a manner to have a common part thereof. Thereby, an entire alignment system can be made to be compact. Consequently, a position measurement accuracy can be improved.

Compact reticle/wafer alignment system

An alignment detection apparatus for detecting the alignment of a superfine exposure system including an interrupted emission light source. The apparatus is equipped with an output variation monitoring sensor to detect an output variation of the light source and further a photoelectric conversion device to perform the photoelectric conversion of the alignment light to generate discrete photoelectric conversion signals. Also included in the apparatus is an integration and hold circuit to integrate and peak-hold each of the photoelectric conversion signals. This peak-hold values are corrected on the basis of the detected light-source output variation due to the monitoring sensor to output stepwise continuous signals from which a harmonic component is removed by a filter so as to obtain a smooth analog waveform. This analog waveform is processed by a phase detector. The output of the phase detector allows an accurate alignment irrespective of using the interrupted emission light source.

Optical alignment detection apparatus

A first reticle is located at an object position of a lens to be evaluated. The first reticle is formed with a first diffraction grating. A stage supports the first reticle. A coherent light source illuminates a whole region of the first diffraction grating. A spatial filter blocks a 0-order component of diffraction light from the first diffraction grating. A second reticle is located at an image position of the lens and is formed with a second diffraction grating. A stage moves the second reticle within a projection range of the lens. Interference fringes are formed on the second reticle by re-diffraction by the lens. Moire fringes are caused by the second diffraction grating and the interference fringes. The moire fringes are observed.

Apparatus for evaluating a lens

A position signal producing apparatus, for an apparatus for project-printing a pattern on reticle onto a wafer through a project lens with ultraviolet light, for producing a position signal indicative of position of the wafer, comprises: a laser emitting two different frequency components polarized orthogonally with each other which are splitted by a polarizing beam splitter. The first and second components are reflected by first and second mirrors respectively to produce interference fringes at a given place being on an annular region within a circle defined by field angle of the project lens on the reticle through wave plates for circularly-polarizing. Another interference fringes is formed on a diffraction grating of the wafer in correspondence with the interference fringes through the project lens and a lens for achromatizing the project lens at wavelengths of the components. Another interference fringes reflected by the diffraction grating is detected by a photodetector for producing the position signal. The interference fringes may formed on the wafer by another diffraction grating on the reticle illuminated by the first and second components in combination with polarizing elements provided between the reticle and the wafer in replace with the polarizing beam splitter and wave plates.

Position signal producing apparatus for water alignment

A light source emits light having two components which ave slightly-different frequencies and which have different planes of polarization. The emitted light is separated into first, second, and third parts travelling along different paths respectively. First, second, and third reference gratings diffract the first, second, and third light parts respectively. First, second, and third illumination optical systems selectively transmit the diffracted first, second, and third light parts respectively. First, second, and third mark gratings having predetermined orientations are formed on a mask and are illuminated with the first, second, and third light parts coming from the first, second, and third illumination systems respectively. Similarly, first, second, and third mark gratings are formed on a wafer and are illuminated with the first, second, and third light parts coming from the first, second, and third illumination systems respectively. A first device detects first optical beat signals of the diffracted lights coming from the first mark grating on the mask and the first mark grating on the wafer. Similar detection is made for the diffracted lights coming from the other mark gratings on the mask and the wafer.

Alignment apparatus including three beams and three gratings

An optical wavelength converting apparatus for converting the divergent lights by a compact apparatus into a parallel lights comprises a light source, a means for collecting the lights from the light source to introduce them into the optical waveguide of the wavelength converting element, a rotation symmetrical lens disposed on the end portion opposite to the end portion on the side irradiated with the collected lights, thereby to make it possible to convert the divergent lights like Cherenkov radiation lights into parallel lights by a compact apparatus.

Optical wavelength convertical apparatus

A first lens, a second lens, means and a third lens means are arranged successively in a direction of travel of a ray. The first lens means each comprising a single lens element power. The second lens means has a predetermined negative refracting power. The third lens means has a predetermined positive refracting power. A fourth lens means consisting of a plurality of lens elements follows the third lens means in the direction of travel of the ray and has a predetermined positive refracting power. At least one surface of the first, second, third, and fourth lens elements is aspherical. The follwoing conditions (1), (2), and (3) are satisfied:

Optical projection system

A system for controlling the relation in position between a photomask and a wafer for use in manufacturing apparatus of a highly integrated circuit such as large scale integration (LSI). The position control system includes a coherent light source for generating two light beams which are different in frequency and polarizing direction from each other. The light beams from the coherent light source is introduced into a first diffraction grating and the diffracted light from the first diffraction grating selectively pass through a telecentric lens system and are led to second and third diffraction gratings respectively disposed on the photomask and the wafer. Light beat signals are obtained in correspondance with the diffracted light from the second and third difraction gratings and the position relation between the photomask and wafer is controlled on the basis of the phase difference between the obtained light beat signals which corresponds to the position difference between the photomask and the wafer.

Apparatus for controlling relation in position between a photomask and a

A projection optical system for use in a precise copy which uses a pair of catadioptric optical systems consisting of convex mirrors, concave mirrors, and phase correction members is shown. Two catadioptric optical systems commonly use an entrance pupil on a coaxis and are coupled so as to respectively face the phase correction members. Each of the concave mirrors has an opening at the center. Each of the convex mirrors has no opening in one embodiment but has an opening portion at the center in another embodiment.

Projection optical system for use in precise copy

A scanning type projection exposure system includes a source emitting light. The light is applied to a portion of a mask having a preset pattern. At least one optical erect projection sub-system images a portion of the pattern on a substrate. The portion of the pattern corresponds to the portion of the mask exposed to the light. The projection sub-system is subjected to scanning movement. The mask and the substrate are subjected to scanning movement. Relative positions of the mask and the substrate are held fixed during the scanning movement of the mask and the substrate.

Scanning type projection exposure system

An electrical discharge machining apparatus for forming minute holes in a workpiece has a machining electrode supported in V-shaped grooves for forming a minute hole through an electrical discharge between the machining electrode and the workpiece. The machining electrode is movable toward and away from the workpiece. The workpiece is movable between a position below the machining electrode and a position below a microscope disposed in conjugate relation to the machining electrode. After a position to be machined has been set by the positioning means, the workpiece is moved to the position below the machining electrode for electrical discharge machining. The machining electrode is subjected to little displacement while it is being rotated, and the position to be machined can be determined with high accuracy. The electrical discharge machining apparatus can quickly form a neat minute hole of small out-of-roundness and reduced surface roughness in the workpiece at a correct position thereon.

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Kawasaki, Japan

Takeo Sato