Kasper Instruments, Inc.

Optimetrix Corporation

Eaton Corporation

Automated Equipment LLC

Karl-Heinz Johannsmeier

Edward H Phillips

Tor G Larsen

Paul E Stoft

In an X-Y addressable workpiece positioner the workpiece to be positioned, such as a semiconductive wafer to be aligned with a mask image, is coupled to move with a work stage moveable in X and Y direction and having a two-dimensional array of positioning indicia affixed thereto for movement therewith. An enlarged image of a portion of the positioning array is projected onto a relatively stationary sensor stage to derive an output determinative of the X and Y coordinates of the positioning array relative to the position of the sensor. The sensed X and Y coordinates of the positioning array are compared with the X and Y coordinates of a reference positioning address to derive an error output. The work stage is moved in response to the error output for causing the workpiece to be positioned to the reference address. In a preferred embodiment of a mask aligner, the approximately stationary sensing stage is moved relative to the enlarged image of the positioning array for interpolating the X and Y coordinates of the sensed address. A viewing system is arranged for permitting the operator to superimpose the image of a pattern on the reference addressed position of the semiconductive wafer with a mask image. The sensing stage is moved by the operator to obtain precise registration of the images, thereby zeroing the reference position address to the interpolated value. The machine then sequentially steps the interpolated (zeroed) reference position address by predetermined increments, related to the size mask pattern to be projected onto the wafer, to cause the wafer to be sequentially exposed to the mask pattern in different regions thereof.

X-Y addressable workpiece positioner and mask aligner using same

A step-and-repeat alignment and exposure system is provided with an adjustable holder for holding a main reticle, a main optical unit including a projection lens for producing an image of the main reticle at an image plane, a stage movable along coordinate axes adjacent to the image plane, and a holder rotatably mounted on the stage for holding a semiconductive wafer to be aligned with respect to the image of the main reticle. The system is further provided with an adjustable holder for holding an auxiliary reticle, a single channel auxiliary optical unit including a main objective lens for producing an image of the auxiliary reticle at the image plane, and a reference mark disposed on the stage and aligned with respect to the coordinate axes. The stage may be controlled for positioning the reference mark directly beneath either the projection lens or the main objective lens of the single channel auxiliary optical unit so that the images of both the main reticle and the auxiliary reticle may be aligned with respect to the reference mark and, hence, with respect to the coordinate axes, and so that the relative spacing between these images may be determined and checked from time to time. This permits the main optical unit and the auxiliary optical unit to be employed interchangeably in globally and precision region-by-region aligning the semiconductive wafer with respect to the coordinate axes prior to employing the projection lens in the photometric step-and-repeat printing of the image of the main reticle at each of an array of different regions on the semiconductive wafer. The system also includes a light source unit for selectively frontally illuminating the entire field of view of the main objective lens of the single channel auxiliary optical unit with white light not passing through the auxiliary reticle.

Step-and-repeat projection alignment and exposure system with auxiliary

A device is disclosed for use on a projection type semiconductive wafer precision step-and-repeat alignment and exposure system for on-machine inspection of a reticle containing the circuitry to be printed on the wafer. Two apertured optical detectors are aligned with identical portions of the projected image of the reticle and scanned across the image of the reticle. Any difference in the electrical response of the two optical detectors indicates dirt or a flaw in the reticle.

On machine reticle inspection device

In an X-Y addressable workpiece positioner the workpiece to be positioned, such as a semiconductive wafer to be aligned with a mask image, is coupled to move with a work stage moveable in the X-Y direction and having a two-dimensional array of positioning indicia affixed thereto for movement therewith. An enlarged image of a portion of the positioning array is projected onto a relatively stationary sensor stage to derive an output determinative of the X and Y coordinates of the positioning array relative to the position of the sensor. The sensed X and Y coordinates of the positioning array are compared with the X and Y coordinates of a reference positioning address to derive an error output. The work stage is moved in response to the error output for causing the workpiece to be positioned to the reference address. In a preferred embodiment of a mask aligner, the approximately stationary sensing stage is moved relative to the enlarged image of the positioning array for interpolating the X and Y coordinates of the sensed address. A viewing system is arranged for permitting the operator to superimpose the image of a pattern on the reference addressed position of the semiconductive wafer with a mask image. The sensing stage is moved by the operator to obtain precise registration of the images, thereby zeroing the reference position address to the interpolated value. The machine then sequentially steps the interpolated (zeroed) reference position address by predetermined increments, related to the size mask pattern to be projected onto the wafer, to cause the wafer to be sequentially exposed to the mask pattern in different regions thereof.

X-Y Addressable workpiece positioner and mask aligner using same

A step-and-repeat alignment and exposure system is provided with a main stage controlled for movement along orthogonal X and Y axes to position either a reference mark or a semiconductive wafer directly beneath a projection lens of the reduction type. The reference mark is formed on a reference mark plate mounted on a substage which is in turn mounted on the main stage and provided with adjustment screws for manually positioning the reference mark plate in a plane parallel to an image plane of the projection lens and for manually positioning the reference mark in alignment with one of the axes of motion of the main stage. Another stage is disposed above the projection lens and controlled for movement along the X and Y axes and about an orthogonal Z axis to position a reticle, held by a vacuum holder and selectively illuminated by a light source unit, with respect to the reference mark. Images of the illuminated portions of the reticle are projected onto the reference mark or the semiconductive wafer by the projection lens. A beam splitter is disposed between the projection lens and the reticle to provide a port for viewing aerial images of the portions of the reference mark or the semiconductive wafer illuminated by the projected images of the illuminated portions of the reticle.

Alignment and exposure system with an indicium of an axis of motion of

An apparatus for automatically aligning a semiconductor wafer with a mask in the manufacture of integrated circuit devices is disclosed. The mask and wafer are each provided with alignment patterns, the alignment pattern on the wafer cooperating with the alignment pattern on the mask in a unique visual mannner to signify alignment. A scanning mechanism is provided for automatically scanning the alignment pattern areas and producing output signals indicative of the relative positions of the alignment patterns on the wafer and mask. Logic circuitry is provided for operating in response to any misalignment represented by the scan output signals to compute formulae which are utilized to produce control signals for driving motor drive mechanisms to produce relative movement between the mask and wafer to bring them into alignment. Several separate alignment cycles are provided, if needed, for zeroing in on finalized alignment. A tolerance selection control circuit is provided for permitting a variation in final alignment tolerance.

Apparatus for the automatic alignment of two superimposed objects, e.g.

An apparatus for automatically aligning a semiconductor wafer with a mask in the manufacture of integrated circuit devices is disclosed. The mask and wafer are each provided with alignment patterns, the alignment pattern on the wafer cooperating with the alignment pattern on the mask in a unique visual manner to signify alignment. A scanning mechanism is provided for automatically scanning the alignment pattern areas and producing output signals indicative of the relative positions of the alignment patterns on the wafer and mask. Logic circuitry is provided for operating in response to any misalignment represented by the scan outout signals to compute formulae which are utilized to produce control signals for driving motor drive mechanisms to produce relative movement between the mask and wafer to bring them into alignment. Several separate alignment cycles are provided, if needed, for zeroing in on finalized alignment. A tolerance selection control circuit is provided for permitting a variation in final alignment tolerance.

Apparatus for the automatic alignment of two superimposed objects, for

An apparatus for automatically aligning a semiconductor wafer with a mask in the manufacture of integrated circuit devices is disclosed. The mask and wafer are each provided with alignment patterns, the alignment pattern on the wafer cooperating with the alignment pattern on the mask in a unique visual manner to signify alignment. A scanning mechanism is provided for automatically scanning the alignment pattern areas and producing output signals indicative of the relative positions of the alignment patterns on the wafer and mask. Logic circuitry is provided for operating in response to any misalignment represented by the scan output signals to compute formulae which are utilized to produce control signals for driving motor drive mechanisms to produce relative movement between the mask and wafer to bring them into alignment. Several separate alignment cycles are provided, if needed, for zeroing in on finalized alignment. A tolerance selection control circuit is provided for permitting a variation in final alignment tolerance.

A wafer-bearing chuck, an annular reference plate, a copy lens system, and a mask-bearing holder are mounted on a floating unit so that the copy lens system produces an image of a pattern-bearing surface of the mask at a plane positioned between the annular reference plate and the wafer chuck and produces an image of a selected pattern-bearing region of a photosensitive-film-bearing surface of the wafer at the pattern-bearing surface of the mask. The wafer chuck is movably mounted for positioning the photosensitive-film-bearing surface of the wafer in abutment with the annular reference plate in a plane parallel to the image plane of the pattern-bearing surface of the mask and for subsequently positioning the selected pattern-bearing surface region of the wafer in the image plane of the pattern-bearing surface of the mask. A stop mechanism may be employed to automatically stop the wafer chuck when the selected pattern-bearing surface region of the wafer is substantially positioned in the image plane of the pattern bearing surface of the mask. Alternatively, the wafer chuck may be manually adjusted, while viewing the pattern-bearing surface of the mask and the image of the selected pattern-bearing surface region of the wafer through a microscope of an optical unit, to precisely position the selected pattern-bearing surface region of the wafer in the image plane of the pattern-bearing surface of the mask. The mask holder is movably mounted for thereafter aligning the pattern of the mask with the image of pattern of the selected surface region of the wafer while they are viewed through the microscope. The floating unit is floatingly supported within a base unit on three balls and coupled to the base unit by a parallelogram linkage so that the floating unit may be scanned relative to the microscope without rotating relative to the base unit to facilitate and verify alignment of all portions of the pattern of the mask with the image of the pattern of the selected surface region of the wafer. A vacuum clamping mechanism may be employed to clamp the floating unit in any position to which it may be scanned, whereupon the mask holder may be moved to further align the pattern of the mask with the image of the pattern of the selected surface region of the wafer. Upon completion of the pattern alignment operation, the floating unit is unclamped and a centering mechanism employed to automatically return the floating unit to a central position at which an exposure lens system of the optical unit may be employed for exposing the photosensitive film on the selected surface region of the wafer in accordance with the pattern of the mask. A loading arm is mounted on a movable stage secured to the floating unit and is rotated in a plane orthogonally intersecting the first optical axis to move the wafer between a loading station and the wafer chuck. The movable stage is stepped to a plurality of different positions arranged in orthogonal rows and columns so that the loading arm may be employd to move the wafer to a corresponding plurality of different positions on the wafer chuck. This permits a corresponding plurality of different regions of the photosensitive-film-bearing surface of the wafer to be aligned and exposed in accordance with the pattern of the mask.

Step-and-repeat projection alignment and exposure system

Apparatus for the automatic alignment of two superimposed objects for

A support arm for a wire bonding tool is fixedly mounted at one end on a first horizontal X-Y stage and is attached at the other end to a swing block by a pair of flexible reeds. The wire bonding tool is mounted on the swing block by another pair of flexible reeds. Both pairs of flexible reeds are arranged to permit vertical motion of the wire bonding tool along a Z-axis toward and away from a workpiece supported beneath the wire bonding tool on a second horizontal X-Y stage. A bell crank is coupled between the support arm and the swing block and is operated by a push rod to control the vertical Z-axis motion of the wire bonding tool. The push rod is coupled at one end to the bell crank and at the other end to a lower coupling member rotatably mounted on the first X-Y stage as part of an Oldham coupling mechanism. An upper coupling member of this Oldham coupling mechanism is rotatably mounted on a support bracket adjacent to the first X-Y stage. The upper coupling member is operated by a cam-controlled linkage mechanism to rotate the lower coupling member and thereby move the push rod as required to operate the bell crank and control the vertical Z-axis motion of the wire bonding tool.

Wire bonding apparatus with improved Z-axis motion control

A wafer-bearing chuck, an annular reference plate, a copy lens system, and a mask-bearing holder are mounted on a floating unit so that the copy lens system produces an image of a pattern-bearing surface of the mask at a plane positioned between the annular reference plate and the wafer chuck and produces an image of a selected pattern-bearing region of a photosensitive-film-bearing surface of the wafer at the pattern-bearing surface of the mask. The wafer chuck is movably mounted for positioning the photosensitive-film-bearing surface of the wafer in abutment with the annular reference plate in a plane parallel to the image plane of the pattern-bearing surface of the mask and for subsequently positioning the selected pattern-bearing surface region of the wafer in the image plane of the pattern-bearing surface of the mask. A stop mechanism may be employed to automatically stop the wafer chuck when the selected pattern-bearing surface region of the wafer is substantially positioned in the image plane of the pattern-bearing surface of the mask. Alternatively, the wafer chuck may be manually adjusted, while viewing the pattern-bearing surface of the mask and the image of the selected pattern-bearing surface region of the wafer through a microscope of an optical unit, to precisely position the selected pattern-bearing surface region of the wafer in the image plane of the pattern-bearing surface of the mask. The mask holder is movably mounted for thereafter aligning the pattern of the mask with the image of pattern of the selected surface region of the wafer while they are viewed through the microscope. The floating unit is floatingly supported within a base unit on three balls and coupled to the base unit by a parallelogram linkage so that the floating unit may be scanned relative to the microscope without rotating relative to the base unit to facilitate and verify alignment of all portions of the pattern of the mask with the image of the pattern of the selected surface region of the wafer. A vacuum clamping mechanism may be employed to clamp the floating unit in any position to which it may be scanned, whereupon the mask holder may be moved to further align the pattern of the mask with the image of the pattern of the selected surface region of the wafer. Upon completion of the pattern alignment operation, the floating unit is unclamped and a centering mechanism employed to automatically return the floating unit to a central position at which an exposure lens system of the optical unit may be employed for exposing the photosensitive film on the selected surface region of the wafer in accordance with the pattern of the mask. A loading arm is mounted on a movable stage secured to the floating unit and is rotated in a plane orthogonally intersecting the first optical axis to move the wafer between a loading station and the wafer chuck. The movable stage is stepped to a plurality of different positions arranged in orthogonal rows and columns so that the loading arm may be employed to move the wafer to a corresponding plurality of different positions on the wafer chuck. This permits a corresponding plurality of different regions of the photosensitive-film-bearing surface of the wafer to be aligned and exposed in accordance with the pattern of the mask.

Growing community of inventors

Los Altos, CA, United States of America

Karl-Heinz Johannsmeier