Apparatus and method for making large area electronic devices, such as flat panel displays and the like, using correlated, aligned dual optical systems

Apparatus to project images from reticles onto the photosensitive surface of a single common substrate to produce a large scale integrated image upon said substrate, said apparatus including

• a movable stage for holding said substrate, means for stepping said stage in orthogonal directions in the plane of said substrate,
• a pair of parallel optical systems mounted proximate to said substrate for concurrently projecting dual images upon said glass substrate, said systems having optical axes perpendicular to said substrate, each said optical system including a reticle carrier to carry said reticles and a reticle chuck positioned to receive said reticles one at a time from said reticle carrier and to hold each said reticle during projection of an image carried by said reticle, each said reticle chuck being capable of individual adjustment movement in six degrees of freedom,
• a computer associated with said stepping means and said optical systems for controlling same, said computer storing data pertaining to the relative positions of said stage and each said reticle and utilizing same to adjust said stepping means and said reticle chuck prior to each said image projection,
• whereby said projected images will be properly aligned relative to one another to produce a unitary, integrated image on said photosensitive surface.

Apparatus to produce large scale integrated images on the photosensitive surface of a substrate, said apparatus including

• a movable stage, means for stepping said stage in the x-and y-directions,
• a pair of parallel and proximate optical systems having axes in the z-direction and positioned above said stage for projection of images thereupon, said optical systems including a reticle chuck operatively associated with each said optical system, for carrying reticles bearing alignment marks to be projected upon said stage,
• sensing means for comparing the position of said projected alignment marks on said stage as said stage is stepped throughout its movement range beneath said optical systems and for determining and recording the extent of variation of said stage from its theoretically true x-, y-, and .phi.-positions throughout said range,
• and means for varying the stepping of said stage from theoretical stepping distances to compensate for said variation in each position of said stage within said range,
• whereby images formed upon said photosensitive surface will accurately abut with one another.

Apparatus for making large area electronic devices utilizing horizontal alignment of images from two optical systems, said apparatus including

• a movable stage adapted for motion in x- and y-directions,
• a pair of parallel and proximate optical systems having axes in the z-direction and positioned to receive reticles in their object planes and to project images from said reticles upon said stage,
• a reticle carrier associated with each said optical system and a reticle alignment chuck associated with each said reticle carrier and adapted to receive a reticle from its respective said carrier and to hold said reticle in the object plane of its respective said optical system, and
• alignment means associated with said optical systems including
• (i) control means associated with each said reticle chuck for adjusting same in any of six degrees of freedom,
• (ii) means for varying the distance between said optical axes, and
• (iii) means for varying the magnification of said optical systems,
• whereby images projected by each said optical systems may be butted with one another and with images from the other of said system to produce large scale images suitable for said displays.

Apparatus for forming abutting images upon the photosensitive surface of a substrate, said images serving to form a display, said apparatus including

• a movable stage for holding said substrate, said stage including preliminary alignment means for said substrate,
• a pair of reticle chucks adapted to receive and hold reticles for projection upon said substrate, a light source and an optical system associated with each said chuck positioned to simultaneously project an image from each of said reticles held by said chucks upon different portions of said substrate, said optical systems having parallel optical axes, and
• means for adjusting the relative positions of said chucks and said optical systems so that multiples of said images are abutting and in alignment upon said substrate,
• whereby said images form a continuum with one another upon said substrate.

Apparatus for producing large area electronic devices and having rapid throughput, said apparatus including

• a frame,
• a stage carried by said frame for motion in x- and y-directions, said stage being adapted to hold a substrate,
• a pair of parallel and proximate optical systems having lenses with their axe in the z-direction and positioned to project images upon said substrate held by said stage,
• sensors associated with said stage for determining the x-, y-, and .phi.-positions of said stage relative to said optical systems,
• a pair of reticle alignment chucks mounted on said frame, each said chuck being operatively associated with one of said optical systems, said reticle chucks being capable of adjustment in six degrees of freedom,
• a stage alignment function providing coordinates of motion of said stage relative to each said reticle chuck,
• stepping means for said stage, and
• control means to adjust the position of said reticle chucks in accordance with said stage alignment function,
• whereby multiple abutting images can be projected through said optical systems to create a uniform, integral image upon said substrate.

In an apparatus adapted to project simultaneous images, from reticles carried by a pair of parallel optical columns, upon a common substrate, to produce a single unified image, said columns being mounted with axes perpendicular to a stage carrying a substrate, said stage being adapted for stepping motion in orthogonal directions perpendicular to the axes of said columns, that improvement including

• an asymmetric projecting lens in each said optical column for projecting said images, each said lens having magnification adjustment capability on its reticle side and focus adjustment capability on its substrate side,
• a reticle chuck in each said optical column positioned to hold a reticle during projection of a said image, each said reticle chuck being independently adjustable in six degrees of freedom to permit positioning of said reticle for control of magnification, rotation, size and shape, and
• control means to control the adjustment of each said reticle,
• whereby images from each said optical column can be adjusted independently to permit proper alignment for the creation of a single integral image on said substrate formed from multiple simultaneous images projected from said two columns.

The method of making displays on a photo-sensitive coated substrate carried by a movable stage, and using a pair of parallel optical columns with axes perpendicular to said stage, including the steps of

• positioning said substrate on said stage,
• simultaneously projecting a pair of aligned images, one from each of said optical systems upon said stage,
• stepping said stage a predetermined distance in a given direction and thereafter again projecting said images upon said substrate, each of said new images being in abutting and aligned relationship with one of said previously projected images, and
• repeating said stepping and projecting steps until said substrate carries an integral image layer formed of a plurality of said abutting images,
• whereby one layer of an integral display has been projected upon said photosensitive substrate.

The method of correcting for variations in translatory movement of a movable stage used in apparatus for making displays, said apparatus including a pair of parallel and proximate optical columns to project images upon a substrate carried by said stage, said method including

• determining the actual positions of said stage as it is moved throughout its range of movement,
• determining the apparent position of said stage as determined by projecting images from said optical columns to sensors on said stage,
• comparing the differences between said actual and apparent positions and recording them as a transfer function, and
• varying the position of said stage relative to said optical columns in accordance with said transfer function,
• whereby images projected by said optical columns upon said substrate will accurately abut.

The method of aligning multiple images being projected from a reticle to a photo-sensitive coated substrate using a pair of parallel and proximate optical systems, said systems being positioned to project in the z-direction upon a movable stage subject to controlled motion in the x-, y-, and .phi. directions, said method including the steps of

• determining the coordinates of motion of said stage relative to images projected from said reticles,
• determining the reticle coordinates of each said reticle by projection of images upon sensors positioned in known locations in said stage,
• using said determined coordinates of said stage and said determined reticle coordinates to determine a first transfer function for said system relative to positions of said stage,
• positioning a said substrate in said stage and applying said first transfer function to adjust the relative positions of said reticles and said substrate for accurate image projection, and thereafter projecting an image upon said substrate,
• stepping said stage to a position to permit projection of an abutting image, and again applying said first transfer function to adjust the relative positions of said reticles and said substrate for accurate image projection, and thereafter projecting an image upon said substrate, and
• repeating the steps of stepping said stage, applying said first transfer function, and projecting said image until sufficient images have been projected upon said substrate to make up an integrated level of a display.

A flat panel display containing a multiplicity of repetitive stitched images and a plurality of layers, said display including

• a substrate,
• a plurality of aligned, etched layers formed using photoresist material upon said substrate, each of said layers having been formed by simultaneous projection of images upon said photoresist material from a reticle carried in each of at least a pair of optical columns, said images each covering a small portion of said substrate but having been repeatedly stepped and reprojected from each said optical column over said substrate so as to form a continuum of interfitting images to form a total, unitary image on said photoresist of said layer,
• said images from each of said optical columns having been separately adjusted before each stepping and projection to match and abut one another in respect to size, shape, rotation, and magnification,
• whereby said flat panel display is formed of a plurality of unitary, integral layer of circuitry.