摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
On a substrate are configured piezoelectric elements composed of a mirror device, piezoelectric thin films, electrodes, and elastic members, and application of a voltage to the electrodes causes flexure deformation in the piezoelectric thin films, so that the mirror device is actuated. A plurality of the piezoelectric elements are arranged in parallel with a longitudinal direction thereof, and torsion springs are provided so as to extend in a direction orthogonal to the longitudinal direction and so as to hold the mirror device in connection with the substrate. The mirror device is connected to the piezoelectric elements through strain absorbers. In such a configuration, the torsion springs serve as a rotation axis, and the mirror device is inclined about the rotation axis.
摘要:
In a mechanically scanned ultrasonic probe, an ultrasonic transducer is swingably mounted on a drive shaft which is given a swinging transversal movement and a reciprocating longitudinal movement. The transducer emits an acoustic beam which is steered in a raster format in response to the swing and reciprocating motions. Echos returning from objects contain diagnostic data of a three-dimensional space. All the components are encased in a toothbrush-like housing having a head portion, an intermediate portion and a hand-grip portion. The dual motions are provided by a drive mechanism accommodated in the hand-grip portion and the transducer is accommodated in the head portion. The drive shaft extends through the intermediate portion.
摘要:
A surface acoustic wave actuator is disclosed which includes unidirectional interdigital transducers disposed on both sides of a vibrator and an electrical combiner. One of the unidirectional interdigital transducers and external power supply are connected to an input port, and the other unidirectional interdigital transducer is connected to an output port of the electrical combiner. The electrical combiner combines input energy from an external power supply and surface acoustic wave energy is electrically converted by one of the unidirectional interdigital transducers, and input to the other unidirectional interdigital transducer. Surface acoustic waves excited by the other unidirectional interdigital transducer propagates on a vibrator, and is input to the other unidirectional interdigital transducer again after passing one unidirectional interdigital transducer and the electrical combiner. A relative movement member is pressed against the vibrator for generating driving force via a friction force so that the relative movement member implements relative movement to the vibrator.
摘要:
A color separation optical system includes a set of prisms which separate incident light into components having different wavelengths. Image pickup devices may be exposed to the separated light components. An arrangement prevents or reduces the influence of a temperature variation upon color separation characteristics. The color separation optical system may be manufactured in a new way.