Censor Patent- Und Versuchs-anstalt

Perkin-elmer Censor Anstalt

The Perkin-elmer Corporation

Herbert E Mayer

Ernst W Lobach

Werner Tabarelli

Ernst W Loebach

Described is a method for facilitating the alignment of a photomask with individual fields on the surfaces of a number of wafers onto which fields the pattern of the photomask is to be imaged for projection printing, each of said number of wafers carrying an identical array of fields produced in at least one previous printing process. For this purpose it is possible to choose one out of the identical batch of wafers, measure the rotational adjustment necessary to bring each field into the correct direction in the horizontal plane and to use the measured value for an automatic rotational adjustment of all other wafers of the batch.

Method for facilitating the alignment of a photomask with individual

An apparatus for determining the focus state of a system for the projection exposure of a mask on a semiconductive substrate for producing integrated circuits without relatively displacing the mask, projection objective and substrate along the common optical axis, utilizes an arrangement for varying cyclically the optical path length for rays at least arising from a projected image on the substrate and running through the objective to a detector plane so that an intensity measurement of the light intensity at this plane indicates the path length required for sharpness and hence the focus state of the projection assembly.

Apparatus for projecting a pattern on a semiconductor substrate

For a device for projection copying of masks on a semiconductor substrate for the manufacture of integrated circuits, it is intended that the copying of an adjusting mark of the workpiece onto a sensor takes place by means of the projection lens, whereby the directly reflected beams of the light which makes visible the adjusting mark are masked out by a mirror, and the position-sensitive sensor is fastened at the underside of the frame carrying the mask.

Device for projection copying of masks onto a workpiece

In order to determine magnification and/or alignment in a device for the projection printing of a pattern on a mask onto a substrate an adjustment plate insertable below the projection lens is provided, said adjustment plate being provided with light-transmitting zones conjugated with recesses in the mask in respect of the projection lens in the exposure light, photometer means being arranged below said light-transmitting zones.

Device for the projection printing of masks into a workpiece

Process and device for relatively aligning the image and object surfaces

In a dampening arrangement for oscillations occurring in rapidly stepwise displacements of a cross slide system of a circuit printing machine, the moving part is with one portion thereof immersed in a viscous dampening liquid within a cavity. Between the walls of the cavity and the outer surfaces of the immersed portion there is formed a small gap, the width of which is calculated by a special formula and which is in the range between 10.mu. and 100.mu., preferably between 25.mu. and 60.mu., and optimally about 40.mu.. Within this gap a friction between the moving part, the liquid layers, and the stationery surface occurs, so as to dampen any oscillations of the moving part in a short decay time.

Dampening system

In the photoexposure of semiconductor wafers for the production of circuit elements, the wafers are placed in a prealignment position before being transferred to the exposure stage. A chuck acting as a prepositioning stage is rotatable by one servomotor to set the wafer in its appropriate angular position (.phi. adjustment) and is shiftable by respective servomotors in the X and Y directions. Servomotor control is effected by optical means detecting a noncircular edge portion of the wafer as well as alignment marks on the wafer inwardly of the edge thereof.

Method of and apparatus for the positioning of disk-shaped workpieces,

A support for a semiconductor wafer about to be subjected to exposure through a photomask, e.g. a rotatable chuck, comprises a stage to which the wafer is temporarily adhered by suction and whose temperature is controlled by an array of Peltier elements responsive to a thermoelectric sensor disposed close to the wafer-carrying stage surface. The Peltier elements are horizontally arrayed in a rectangular block inserted between the stage and an underlying base of the support, the block being cemented into a metal frame which has only limited contact with the stage and the base to minimize heat conduction therebetween. The base has channels for the circulation of a temperature-modifying fluid such as water.

Temperature-controlled support for semiconductor wafer

Method of positioning disk-shaped workpieces, preferably semiconductor

An arrangement for projection copying of masks onto a workpiece, in particular onto a semiconductor substrate for producing integrated circuits, wherein the images of the patterns of the masks are formed by a projection lens on a photosensitive layer on the workpiece. The projection lens is completely corrected at the exposure wavelength used, and alignment patterns of the mask are aligned relative to adjustment marks on the workpiece, after images of the alignment pattern and the adjustment mark have been formed in the same plane, with adjustment exposure, by the projection lens and possibly an auxiliary optical means. The formation of the images of the adjustment marks in the plane of the alignment pattern or the alignment pattern in the plane of the adjustment marks is effected by means of the projection lens and possibly the auxiliary optical means, with an image defect which changes points to lines extending sagittally or meridionally with respect to the optical axis, and that the adjustment marks and the alignment pattern include lines which correspondingly extend sagittally and meridionally respectively with respect to the optical axis.

Arrangement for projection copying masks on to a work piece

In a method for the projection printing of masks onto a wafer coated with a photosensitive layer, said mask and said wafer being aligned by imaging alignment patterns of said mask onto said wafer by means of alignment light. In order to obtain a high-intensity and high-contrast alignment signal generated by plotting said alignment light reflected from said wafer, said alignment light comprises at least two narrow wavelength ranges spaced from each other on the wave length scale, in said ranges said photosensitive layer of said workpiece being non-sensitive or low-sensitive, determining the intensity of said alignment light reflected from said workpiece and generating an alignment signal from the wavelength range of said alignment light having highest intensity.

Method for the projection printing

A method and a device for controlling operating processes applied to particles. The device comprises a number of operating stations, such as, lifting- and sluing conveyors to allow for feeding the particles to an indexing rotary plate and conveying of particles to a processing stage, e.g. a welding device. The operating processes of the operating stations are initiated according to a common, pre-set cycle, at least one of the operating stations is associated with a correcting process initiated by a sensor arrangement for detecting faults in the operating process, for shortening the outages and for increasing the total output. The operating process involving a fault detected by the sensor arrangement is immediately interrupted, whereupon the correcting process is initiated independently of the common, pre-set cycle. The common, pre-set cycle serves to initiate dependent subsequent or previous operating processes of the operating stations until the end of the correcting process.

Method for controlling operating processes

A device for fixing a planar work piece in position, particularly a semiconductor used in processing cycles for the production of integrated circuits. Said device having a supporting plane, a number of apertures being disposed in said supporting plane, said apertures being under reduced pressure, said work piece being pressed against said supporting plane by means of said reduced pressure. Said device being particularly suitable for precisely fixing a semiconductor substrate in the supporting plane, even in the case of extensive raised areas or warps on the lower side of the substrate. A number of independent reduced pressure systems are provided, said reduced pressure systems being connected with individual apertures or groups of apertures.

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Eschen, Liechtenstein

Herbert E Mayer