Nippon Kogaku K.k.

Nikon Corporation

Satoru Anzai

Kyoichi Suwa

Hiroshi Tanaka

Makoto Uehara

Masaya Komatsu

Kazuaki Suzuki

Koichi Matsumoto

Kazuo Ushida

Toshio Matsuura

Koichi Ohno

Masashi Okada

Hisayuki Shimizu

A photomask is provided having a stepped portion formed on at least one of a first and second areas corresponding to a stepped structure within an exposure area on the sensitive substrate onto which the pattern is to be exposed to make different height positions of the first and second areas of the pattern forming surface of the transparent substrate in the optical axis direction of the projection optical system. Also provided is an exposure method involving the step of shifting an image forming surface of a projection optical system in an optical axis direction corresponding to a stepped structure of an exposure area on a sensitive substrate, The image forming surface of the projection optical system coincides with the exposure area surface when exposing the pattern on an original substrate onto the sensitive substrate through the projection optical system. A projection exposure apparatus is also provided including a projection optical system for projecting and forming an image of a pattern on the original substrate on the sensitive substrate, and a stage for retaining the sensitive substrate so that the surface of the sensitive substrate is disposed close to the image forming surface, The exposure apparatus also has an image surface compensating member for shifting the image forming surface in the optical axis direction corresponding to the stepped structure.

Photomask, an exposure method and a projection exposure apparatus

A photomask is provided having a stepped portion formed on at least one of a first and second areas corresponding to a stepped structure within an exposure area on the sensitive substrate onto which the pattern is to be exposed to make different height positions of the first and second areas of the pattern forming surface of the transparent substrate in the optical axis direction of the projection optical system. Also provides is an exposure method involving the step of shifting an image forming surface of a projection optical system in an optical axis direction corresponding to a stepped structure of an exposure area on a sensitive substrate. The image forming surface of the projection optical system coincides with the exposure area surface when exposing the pattern on an original substrate onto the sensitive substrate through the projection optical system. A projection exposure apparatus is also provided including a projection optical system for projecting and forming an image of a pattern on the original substrate on the sensitive substrate, and a stage for retaining the sensitive substrate so that the surface of the sensitive substrate is disposed close to the image forming surface. The exposure apparatus also has an image surface compensating member for shifting the image forming surface in the optical axis direction corresponding to the stepped structure.

An apparatus for projecting a pattern on a first plane onto a second plane comprises a projection lens system disposed between the first plane and the second plane and including a plurality of lens elements disposed at intervals, a plurality of spaces defined by the plurality of lens elements being formed, and means for isolating at least one of the plurality of spaces from the atmosphere. The at least one space is determined so that the variation in magnification of the projection lens system when the pressure in the at least one space varies with the atmospheric pressure is substantially equal to the variation in magnification of the projection lens system when all of the pressure in the space formed between the first plane and the projection lens system, the pressures in the plurality of spaces of the projection lens system and the pressure in the space formed between the projection lens system and the second plane vary with the atmospheric pressure.

Projection optical apparatus

In a method and apparatus for highly precisely adjusting the optical performance including the imaging plane and the magnification factor of a projection lens in a projection optical apparatus, adjustment of the projection lens is achieved by changing the barometric pressure, i.e., the refractive index of at least one space which is located on an optical path and which is shielded from the outer atmosphere is changed by changing the barometric pressure therein. At this space, a space or gap present between any two adjacent elements of a plurality of lens elements or a group of lenses constituting a projection lens is preferably selected. The selected space is independent from and is shielded from the outer atmosphere by the lenses defining itself and a housing supporting these lenses, and is filled with air or a gas. The pressure of the air or gas inside the independent space is controlled by a barometric controller.

Method and apparatus for adjusting imaging performance of projection

An exposure method for photolithography comprises the steps of forming a pattern on a substrate by the use of a first exposure apparatus including a first imaging optical system having a reduction magnification 1/.beta.1 and an image circle of a diameter .phi.1, and forming a second pattern on the substrate on which the first pattern has been formed, by the use of a second exposure apparatus including a second imaging optical system having a reduction magnification 1/.beta.2 different from the reduction magnification 1/.beta.1 and an image circle of a diameter .phi.2, wherein when N is an integer, the conditions that .beta.1.times..phi.1=.beta.2.times..phi.2 and .phi.1=N.times..phi.2 are satisfied.

Exposure method and system for photolithography

An apparatus for projecting the image of an object onto a substrate comprises light source means for supplying light energy for illuminating the object, optical means for forming the image of the object on the substrate, the image magnification of the optical means being heated and varied by the light energy from the light source means, means for monitoring the manner in which the light energy is applied to the optical means, means for determining the variation in the image magnification of the optical means in response to the monitor means, and means for adjusting the size of the image formed on the substrate in response to the determining means.

Automatic magnification correcting system in a projection optical

A control method for the projection optical system of a projection exposure apparatus used in the fabrication of LSIs. The amount of energy incident to the projection optical system during each unit time is maintained constant at all times including each projection and the intervals between the projection operations. This has the effect of cancelling any error in the projected image, particularly any variation of the magnification error with time due to any variation of the optical performance of the projection optical system caused by the illuminating energy.

Light irradiation control method for projection exposure apparatus

A double-conjugate maintaining optical system for maintaining the conjugate relation between an object and its image even if the distance between the object and the image varies and also maintaining another set of conjugate relation in a predetermined condition includes an afocal system comprising a plurality of lens units, a first positive lens unit disposed on the object side of the afocal system, and a second positive lens unit disposed on the image side of the afocal system. The first positive lens unit is movable relative to the second positive lens unit so that the object is positioned on the focal plane of the first positive lens unit opposite to the afocal system. The afocal system is movable along the optical axis thereof in a predetermined relation with the first positive lens unit.

Double-conjugate maintaining optical system

A projection type exposure apparatus has a projection objective lens, a projection negative having a predetermined shape pattern and an alignment mark, and a photosensitive plate having an alignment mark. The shape pattern of the projection negative is projected upon the photosensitive plate by the projection objective lens. Main illuminating optical means illuminates the projection negative with a first wavelength light to which the photosensitive plate is sensitive, and alignment optical means illuminates the projection negative with a second wavelength light to which the photosensitive plate is insensitive. The positional relation between the projection negative and the photosensitive plate is detected using the second wavelength light through the projection objective lens. One of the alignment mark on the projection negative and the alignment mark on the photosensitive plate has a zone pattern which forms a light-condensing point at a position spaced apart by a predetermined amount from the surface on which said one mark is formed, and said predetermined amount corresponds to the amount of chromatic aberration of the projection objective lens, at the side thereof adjacent to said zone pattern, for the second wavelength light relative to the first wavelength light.

Projection type exposure apparatus

A reflection type image forming optical system having a large angle of view comprises a convex mirror for reflecting incident light and a concave mirror. The concave mirror is disposed with the reflecting surface thereof facing the reflecting surface of the convex mirror so that light reflected by the convex mirror at a large angle with respect to the normal thereof enters the concave mirror at a large angle and that light reflected by the convex mirror at a small angle with respect to the normal thereof enters the concave mirror at a small angle. The concave mirror is arranged so that the distance between the center of curvature of the convex mirror and that of the concave mirror is greater than half the radius of curvature of the concave mirror.

Growing community of inventors

Zama, Japan

Satoru Anzai