Abstract: A projection lens distortion error map is created using standard overlay targets and a special numerical algorithm. A reticle including a 2-dimensional array of standard overlay targets is exposed several times onto a photoresist coated silicon wafer using a photolithographic stepper. After exposure, the overlay targets are measured for placement error using a conventional overlay metrology tool. The resulting overlay error data is then supplied to a software program that generates a lens distortion error map for the photolithographic projection system.

Abstract: A process of measuring the radiant intensity profile of an effective source of a projection image system that has an effective source, an object plane, an imaging objective, an exit pupil, and an image plane. The improved process consists of selecting at least one field point and a corresponding aperture plane aperture and projecting a plurality of images of the selected field point through the corresponding selected aperture plane aperture at a plurality of various intensities of the effective source. By analyzing the recorded images of the effective source at various intensities it is possible to determine a radiant intensity profile of the image source at the selected field point.

Abstract: A device, method of measurement and method of data analysis are described for imaging and quantifying in a practice sense the luminous intensity of the effective illumination source of an image system. The device, called a source metrology instrument, produces images and other quantitative measurements of the combined condenser and light source that are taken in-situ and without any significant alteration of the optical or mechanical set up. As such, the device can be used to monitor and assess the coherence properties of the illumination source with a minimum of interruptions to the optical tools productive time. It can be used with photolithographic step and repeat reduction or nonreducing imaging systems (steppers), scanning image systems, fixed field step and repeat aberration systems, scanning aberration systems, or any other projection imaging or aberration systems.

Abstract: A technique for mapping working images to adjacently and continuously tiled subapertures having CGHs on a plate is disclosed with the result that the entirety of a working area of a plate is completely covered with working subapertures, these subapertures usually being rectangular. The design technique thereafter determines a phase function which approximately maps desired regions on each subaperture from portions of the working image in the workpiece plane. Steps in the process include first a determination of the size and shape of subapertures representing each feature. Second, a determination of the geometric transformation for each feature is made. Thereafter, backpropagation or other refinement to create the desired intensity profile at the workpiece is made.

Abstract: An apparatus and process for generating precision ink jet nozzle arrays in substrates is disclosed. The apparatus includes laser output through an alignment path, power monitor, expansion telescope and scanner. Preferably, beam division optics are used in conjunction with the scanner to divide out a plurality of beams and scan simultaneously a corresponding plurality of computer generated holograms (CGHs). These computer generated holograms are configured and scanned so that the generated image--preferably in the first order of diffraction--produces at least a row of ink jet holes having precision dimension and alignment preferably without optical interference from other diffraction orders. Utilizing the disclosed process and apparatus, a one step system is disclosed for going from a substrate to a finished nozzle array suitable for use with ink jet printers.

Abstract: A reticle consisting of a multiplicity of small openings corresponding to separate and distinguishable points is put in the reticle plane. This reticle is imaged down through an opening O in aperture plate AP. A corresponding multiplicity of spots are created at the image plane of the optical system. These spots have spot centroids relative to the original separate and distinguishable points in the reticle. These points, however, are deviated from their diffraction limited positions by the average of grad.phi.(u)) over the corresponding ray bundle. The opening O in the aperture plate samples a discrete portion of the entrance pupil. With points spread out over an area of size 2*NAo*za, ray bundles with chief rays covering the entire entrance pupil will be projected down to image plane IP. The above outlined procedure is extended to analyzing the wavefront at a multiplicity of field points over the entire lens train. The process includes using an aperture plate AP consisting of a multiplicity of openings O.

Abstract: A stepper lens train is mapped for curvature of field and distortion. A single plate, displaced from the reticle plane, is utilized for stepper correction. The plate is provided with a variable thickness mapped to correct curvature of field. The same plate is etched with stepped gratings typically on a flat surface of the plate.

Abstract: A reticle consisting of a multiplicity of small openings corresponding to separate and distinguishable points is put in the reticle plane. This reticle is imaged down through an opening O in aperture plate AP. A corresponding multiplicity of spots are created at the image plane of the optical system. These spots have spot centroids relative to the original separate and distinguishable points in the reticle. These points, however, are deviated from their diffraction limited positions by the average of grad .phi.(u)) over the corresponding ray bundle. The opening O in the aperture plate samples a discrete portion of the entrance pupil. With points spread out over an area of size 2*NAo*za, ray bundles with chief rays covering the entire entrance pupil will be projected down to image plane IP. The above outlined procedure is extended to analyzing the wavefront at a multiplicity of field points over the entire lens train. The process includes using an aperture plate AP consisting of a multiplicity of openings O.

Abstract: A mask for generating a high density regular matrix of working images for generating a corresponding high density regular matrix of vias in a substrate, the computer generated holographic images from overlapped subapertures are processed for maximum fluence. For each working image, a diverging wave front of the first order is propagated using Fresnel diffraction to produce for that wave front the corresponding first order holographic image at a central unit cell. The first order holographic image for each of the working images to be produced by the unit cell is added until the configuration of a unit mask cell containing portions of all working images to be broadcast is attained. The projection from the unit cell to working image is arbitrarily altered to attain the smallest local maximum first order transmission requirement within the central unit cell; the large local maximum first order transmission requirements are essentially moved outside the bounds of the central unit cell.

Abstract: A technique is described which provides for directly placing multiple patterns on a nonconducting substrate using an electron beam. Prior to patterning, a conductive coating is applied to the nonconductive substrate. The patterns are generated by controlling the position and the speed of movement of the electron beam. Each pattern contains fiducials lying outside of the pattern's active region. After a conductive layer has been exposed, the patterned regions are removed, typically through etching. A separate etch is used to etch the pattern into substrate. The unpatterned portions of the conductive coating are then removed and a new conductive coating is applied to the substrate, insuring that the fiducials are protected during the removal procedure so that they can be used to align subsequent patterns. This procedure is repeated as many times as necessary to form the desired number of patterns in the substrate.

Abstract: A beam scanning system and attached system of beam stabilization is utilized for ensuring the parallel transport of a scanned orthogonally deflected coherent light beam. A first scanning stage with right angle reflecting mirror scans the beam in the X-direction and reflects the scanned beam to the Y-direction. A second scanning stage with right angle reflecting mirror is mounted to the first scanning stage. This second scanning stage deflects the scanning beam in the Y-direction and reflects the beam downward. The scanning beam has divided out a small portion thereof as a reference beam. This reference beam is then diverted to precisely opposite orthogonal paths to the incidence of the scanning beam. The precise opposite orthogonal reference path results in upward deflection of the reference beam. After upward deflection, the reference beam is reflected at an optical flat and reflected back through the reference path. After retracing the orthogonal reference legs, the beam is diverted to a quad detector.

Abstract: A apparatus and process for ablating a matrix of high density vias in a flexible substrate. The apparatus is cantilevered on a horizontal shelf from a partition where it can be rigidly supported. A vacuum container reciprocates towards and away from the partition and supports the horizontal shelf by permitting supporting casters to bear on and be supported by the reciprocating container. When the container is away from the partition, servicing of the apparatus as well as the insertion an removal of substrate can occur. When the container is adjoined to the partition, a vacuum can be drawn on the apparatus and processing commenced. A continuous flexible substrate is provided extending in a circuitous path between a supply roll and a take up roll, all interior of the container. The flexible substrate is maintained under constant tension and incrementally advanced. The substrate is incrementally advanced and stopped, passing across a table.

Abstract: The apparatus for machining and material processing includes an excimer laser and a Fresnel zone plate array (FZP) positioned parallel to the workpiece, with the distance between the FZP and the workpiece being the focal length of the FZP. For each hole to be formed on the workpiece a corresponding Fresnel zone is patterned onto the FZP. Each Fresnel zone may be patterned directly centered over the desired hole location or in high density patterns it may be located off-center from the hole with deflection being accomplished by the formation of finer circular arcs on the side of the Fresnel zone opposite the desired direction of deflection. A beam scanner is included to provide a more uniform illumination of the FZP by the laser beam. The scanning eliminates non-uniformity of intensity. The alignment mechanism uses a helium-neon laser, the beam from the which is projected onto a surface relief grating on the workpiece.

Abstract: The process of the manufacture of both the conductive layers and dielectric layers of multichip modules of the deposited variety is set forth with direct etch techniques being substituted for photolithography. Simply stated, entire circuit layers of the modules are directly etched or patterned with the circuit configuration required. Three processes are disclosed for processing the individual layers including subtractive patterning of a metallic conductor layer and direct patterning of the dielectric layer; direct etch metal processing (DEMI) involving direct removal of the metal layer with subsequent direct patterning of the dielectric layer; and, plating form process involving additive metallization and direct etching of the dielectric layer. By utilizing the disclosed processes alone or in combination, fabrication of multichip modules can occur.

Abstract: A stepper configuration is modified by corrector plates so that an image from a reticle plane is projected to an ideal image at an object plane. The system correction is based on the premise that depth of field correction made at the reticle plane induces insignificant distortion correction. Further, distortion correction in turn induces insignificant changes in field correction. The preferred location of plates correcting for depth of field is therefore at the reticle plane, it being noted that distortion introduced by a field corrector plate at this location is negligible. Three generalized cases for correction are therefore discussed. The first case is field curvature correction where the correcting plate is registered to or close to the reticule plate; it is shown that induced distortion correction may be ignored. The second case is where field correction cannot be placed next to the reticle plate, but the field curvature induced by required distortion correction is negligible.

Abstract: Optical machining of a workpiece with coherent light scanning a plate with a plurality of subaperture subapertures is disclosed. Each of the subapertures creates a working image which when scanned with a coherent wave front of the design frequency forms in three dimensional space the working image. The working image when registered to a workpiece effect processing of the workpiece, usually ablating an aperture such as a blind via of small dimension. Improved techniques of dimensioning and fabricating the subaperture, creating amplitude modulation with the phase plate, and finally controlling amplitude with optical features close to the limit of producible optical elements is disclosed. The apparatus for the process, the process and the plate for utilization in the process are set forth.

Abstract: In a system of proximity printing utilizing coherent light, a technique of phase only image correction is disclosed. Specifically, a holographic corrector plate is utilized. The image on the holographic corrector plate is produced by constructing a holographic image from the broadcast image and the intended working image. The broadcast image and the intended working image are placed in precise proximity printing alignment. With the respective images aligned, a coherent light beam is split to provide two temporally and spatially coherent beams. One of the temporally and spatially coherent beams scans the broadcast image. The other temporally and spatially coherent beam scans a mask containing the intended working image in a corresponding scan. A plane of beam intersection is chosen, with precise correspondence between rays at any point on the broadcast mask to rays from corresponding points on the working image mask.

Abstract: In an apparatus and process for the direct ablation of substrates, an optical train is disclosed which enables large substrates to be processed from relatively small optical masks containing subaperture groups. Optical masks, preferably in the form of transparent plates containing computer generated holograms, are provided with at least discrete subaperture groups for sequential scanning and hence sequential processing of the substrate. A scanning beam in combination with a variable aperture overlying the mask sequentially scans the subaperture groups of the plates to produce direct laser ablation from a subaperture group intended to be scanned and prevents partial scanning of adjacent subaperture groups. Specialized plates with overlying generally negative lenses and subapertures elongated with respect to the radial direction of optical divergence are utilized to project images out from under the respective computer generated holograms to locations at the side of the plates without distortion.

Abstract: Transparent and wholly transmissive optical plates are disclosed in which features to be ablated are formed to produce varying levels of transmission of an ablating laser beam, preferably scanned across the plate. Use of the plate for ablation extends to forming openings of varying depths with timed ablating exposures of known intensity. Alternately, the ablation profile of a single image can be controlled utilizing a timed exposure of known intensity to provide an ablated opening of a specific designed profile in a workpiece. Three specific plate image constructions are illustrated. These include gratings which taper in width (continuous and step tapers both being disclosed), randomly placed diffracting elements which taper in density, and gratings having interrupted portions which taper in density. Where the intensity across a feature is uniform, ablation to controlled depths may occur.

Abstract: A method and apparatus is disclosed for laser ablation of openings with a specified wall profile in materials such as polyimide. The method includes identifying the opening profile of choice. This profile of choice is then divided into convex portions which can be "stably" formed and concave portions which are "unstably" formed. With respect to convex portions of apertures, after ablation to their desired depth, these convex portions remain substantially unchanged with additional exposure to otherwise ablating radiation. With respect to concave portions of apertures, these concave portions change with additional exposure to ablating radiation. Accordingly, techniques are disclosed for controlling exposure to ablating radiation, controlling the profile of the ablating radiation, or both. In either case, the intensity profile of the working image containing the ablating light is shaped in accordance with the depth and slope of the sidewalls of the opening desired.