Canon Kabushiki Kaisha

Tamotsu Karasawa

Junji Isohata

Hideki Yoshinari

Ichiro Kano

An alignment and exposure apparatus including a mask chuck for holding a mask, a wafer chuck for holding a wafer, a projection optical system for projecting the image of the mask onto the wafer, a non-contact distance measuring gauge for measuring the distance from a reference position to the wafer without contacting the wafer, a processing unit for calculating, on the basis of the measured distance, data on the position within the depth of field of the projection optical system and to be assumed by the mask, and an adjusting unit for adjusting the position of the mask in the direction of optical axis in accordance with an output from the processing unit so as to meet the data calculated by the processing unit, whereby the mask pattern is correctly focused on the wafer in the non-contact process with respect to the wafer surface.

Focus adjustment in an alignment and exposure apparatus

A printing apparatus for use in the manufacture of semiconductor circuit elements, comprising a fixed mirror imaging system. A mask holder and wafer holder are respectively provided in an upper horizontal plane and a lower horizontal plane on the optical axis above and below said mirror imaging system, the light emerging from the mask being introduced into said system by a mirror inclined at 45.degree. to the optical axis while the light emerging from said system is directed to the wafer by an another mirror inclined at 45.degree. to the optical axis. The mask holder and wafer holder are integrally movable in the horizontal direction to allow formation of the entire image of mask on the wafer.

Printing apparatus

A light-modulating device having an extended range of light modulation comprising a mechanical variable diaphragm means and a neutral density filter arranged to optically cover the aperture opening of said diaphragm means, said filter being characterized as including two regions, one of which is a central uniform density region which is centered at the optical axis, while in the other region contiguous to the central region, the density is decreased with radius. In this manner the amount of light is varied in passing through the light-modulating device as a function of the area of the aperture opening and the transmittance of effective area of the filter. A method of producing filters of such characteristics are also disclosed.

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Kawasaki, Japan

Tamotsu Karasawa