Kla Instruments Corporation

Gte Sylvania Incorporated

Other

Curt H Chadwick

John D Greene

Michael E Fein

William T Bell

Anil A Desai

Robert R Sholes

P C Jann

Francis D Tucker, Iii

John S Taylor

Richard R Simmons

Paul Sandland

Dan J Radecki

Larry Rosenberg

Alex Brudny

Howard I Dwyer

David J Harvey

David J Clark

Lee H Veneklasen

Alan D Brodie

Scott Allen Young

Edward D Reed, Jr

Chung-Shih Pan

Mark Joseph Wihl

Eric Munro

Ralph T Johnson

Chetana Bhaskar

Dan Meisburger

Timothy L Hutcheson

April Dutta

Barry Becker

Jack Y Jau

John McMurtry

Dennis G Emge

Henry Pearce-Percy

Fred E Babian

Kirkwood Rough

Paul Wieczorek

Russell M Singleton

Bin-Ming B Isai

David J Harney

Walter I Novak

Ming-Yie Ling

Hans Dohse

Ray Paul

Mike Robinson

Kent E Douglas

David E Smith

Dean Walters

Nicholas Szabo

Sam Wong

Roger Kroeze

Surendra Lele

Chun C Lin

Hoi T Nguyen

Yen-Jen Oyang

Chris Kirk

John E Raffarin

Joseph D Tajnai

Art M Shulenberger

A method and apparatus, and variations of each, for inspecting a wafer defining at least one die thereon is disclosed. The present invention first obtains the electronic image equivalent of two die, and then determines the x and y offset between those electronic images. Prior to inspection for defects, those two electronic images are aligned by adjusting the x and y positions of one electronic image of one die with respect to the electronic image of the other die. Once that is accomplished, those electronic images are compared to detect any defects that may exist on one of the die.

Alignment correction prior to image sampling in inspection systems

There is disclosed numerous embodiments of a method and apparatus for a particle scanning system and an automatic inspection system. In each of these a particle beam is directed at the surface of a substrate for scanning that substrate. Also included are a selection of detectors to detect at least one of the secondary particles, back-scattered particles and transmitted particles from the substrate. The substrate is mounted on an x-y stage to provide it with at least one degree of freedom while the substrate is being scanned by the/particle beam. The substrate is also subjected to an electric field on it's surface to accelerate the secondary particles. The system also has the capability to accurately measure the position of the substrate with respect to the charged particle beam. Additionally, there is an optical alignment means for initially aligning the substrate beneath the,particle beam means. To function most efficiently there is also a vacuum means for evacuating and repressurizing a chamber containing the substrate. The vacuum means can be used to hold one substrate at vacuum while a second one is being loaded/unloaded, evacuated or repressurized. Alternately, the vacuum means can simultaneously evacuate a plurality of substrates prior to inspection and repressurize of the same plurality of substrates following inspection. In the inspection configuration, there is also a comparison means for comparing the pattern on the substrate with a second pattern.

Electron beam inspection system and method

In each configuration, at least one TDI sensor is used to image substrate portions of interest, with those portions illuminated with substantially uniform illumination. In one configuration, a substrate is compared to prestored expected characteristic features. In a second configuration, first and second patterns in a region of the surface of at least one substrate are inspected by comparing one pattern against the other and noting whether they agree with each other. This is accomplished by illuminating the two patterns, imaging the first pattern and storing its characteristics in a temporary memory, then imaging the second pattern and comparing it to the stored characteristics from the temporary memory. Then the comparisons continue sequentially with the second pattern becoming the first pattern in the next imaging/comparison sequence against a new second pattern. Each time the comparison is performed, it is noted whether or not there has been agreement between the two patterns and which two patterns where compared. This inspection technique is useful for doing die-to-die inspections. A variation of the second configuration uses two TDI sensors to simultaneously image the first and second patterns, thus eliminating the need for temporary memory. In this configuration, the two patterns are simultaneously imaged and compared, then additional patterns are compared sequentially, in the same manner with the results of the comparisons and the pattern locations stored to determine which patterns are bad when the inspection of all patterns is completed.

Automatic high speed optical inspection system

In each configuration, at least one TDI sensor is used to image the portions of interest of the substrate that are substantially uniformly or critically illuminated. In one configuration, the substrate is compared to the expected characteristic features prestored in memory. In a second configuration, a first and second pattern in a region of at least one substrate are inspected by comparing one pattern against the other and noting whether they agree with each other. This is accomplished by illuminating the two patterns, imaging the first pattern and storing its characteristics in a temporary memory, then imaging the second pattern and comparing it to the stored characteristics from the temporary memory. Then the comparisons continue sequentially with the second pattern becoming the first pattern in the next imaging/comparison sequence against a new second pattern. With each comparison whether there has been agreement between the two patterns is noted. After all of the patterns are sequentially compared, the bad ones are identified by identifying those that did not compare with other patterns in the test process. This inspection technique is useful for doing die-to-die inspections, as well as repeating patern inspections within the same die. A variation of the second configuration uses two TDI sensors to simultaneously image the first and second patterns eliminating the need for the temporary memory.

An instrument table having two features is disclosed. The first is a stable instrument bench that is constructed of sections of precast reinforced concrete. Each of these sections are then moisture sealed with a plastic coat or paint, then assembled using epoxy and bolts. The second element of the present invention is the replication of a precision surface on the table portion of an instrument bench. The replication of the precision surface entails the application of a bead of plastic to the selected portions of the instrument table, lowering of a jig having a portion of the underside thereof machined or ground to the selected specifications of the surface to be replicated onto the instrument table thereonto, supporting the jig a selected distance above the surface of the instrument table to push out the plastic into a pad of a thickness that is equivalent to the distance above the table at which the jig is supported, and removing the jig after the plastic is cured thus leaving behind the plastic pad that has thereon a precision surface that replicates the machined or ground surface on the underside of the jig.

Stable instrument bench with replicated precision surface

An instrument table having two features is disclosed. The first is a stable instrument bench that is constructed of sections of precast reinforced concrete. Each of these sections are then moisture sealed with a plastic coat or paint, then assembled using epoxy and bolts. The second element of the present invention is the replication of a precision surface on the table portion of an instrument bench. The replication of the precision surface entails the application of a dollop of plastic to the selected portions of the instrument table, lowering a jig having a portion of the underside thereof machined or ground to the selected specifications of the surface to be replicated onto the instrument table thereonto, supporting the jig a selected distance above the surface of the instrument table to push out the plastic into a pad of a thickness that is equivalent to the distance above the table at which the jig is supported, and removing the jig after the plastic is cured thus leaving behind the plastic pad that has thereon a precision surface that replicates the machined or ground surface on the underside of the jig.

Method of molding a precision surface on an instrument table

Substrate inspection apparatus and methods, and illumination apparatus. The inspection apparatus and method includes memory for storing the desired features of the surface of the substrate, focussed illuminator for substantially uniformly illuminating a region of the surface of the substrate to be inspected. Additionally there is a sensor for imaging the region of the substrate illuminated by the illuminator, and a comparator responsive to the memory and sensor for comparing the imaged region of the substrate with the stored desired features of the substrate. The illumination apparatus is designed to provide substantially uniform focussed illumination along a narrow linear region. This apparatus includes first, second and third reflectors elliptically cylindrical in shape, each with its long axis substantially parallel to the long axes of each of the others. Fourth and fifth reflectors are also included with each being flat and mounted parallel to each other and at opposite ends of each of said first, second and third reflectors, and first, second and third linear light sources each mounted parallel to a corresponding one of said first, second and third reflectors with each of the light sources mounted so that it is at the first focus of the corresponding reflector and the illuminated linear region is at the second focus of each of the first, second and third reflectors.

Method and apparatus for optical inspection of substrates

In an automatic wafer inspection system, the objective lenses used in micro inspection are mounted on a turret which is attached to an adjustable turret support member. Several lenses may be brought sequentially into position for inspection of the patterned wafer and it is necessary that the handoff be precise so as to maintain the same pattern in the viewing position. V-slots are mounted on the turret in such a location as to be correctly associated with the precise position for each lens. A detent ball spring is biased to drive into a V-slot so as to hold the associated lens in the precise viewing position. When hand-off to the next lens is to be accomplished, a counter force is applied which overcomes the spring bias and pulls the detent ball out of the V-slot. A drive motor is then enabled, which turns the turret a predetermined distance to bring the wide opening of the next adjacent V-slot into approximate alignment with the detent ball and the drive motor is disabled. The counter force is released which allows the spring bias to force the detent ball into the now partially aligned V-slot to precisely align the lens and hold the lens in alignment. The adjustable turret support member is then raised or lowered to automatically focus the lens on the patterned wafer.

Rotational and focusing apparatus for turret mounted lenses

An automatic microscope focusing system including a light source 44, a dual channel fiber optics bundle 56 and 58, chopper means 54 for alternately admitting light to the channels, a reticle 66 and associated optics to cast alternating images onto the surface of an inspected article W, return masks 82 and 88, and associated detectors 86 and 92 for inspecting the alternating reticle images, and control circuitry 36 and 38 responsive to the detector outputs and operative to drive the system microscope 10 into focus. The preferred embodiment also includes a flipping pupil 60 for accommodating particular microscope objectives.

Automatic focusing system for a microscope

An automatic semiconductor wafer inspection system including a wafer inspector, a system computer that performs movement and function control and data storage functions and a high speed image computer. Patterned wafers selected for inspection are automatically transported from cassette storage to a vacuum chuck located on the X-Y stage and positioned in a macro inspection station. The wafer is aligned and the surface illumination is changed to test for macro defects under different lighting conditions and levels of magnification. The reflected light is applied to a camera where the optical image is converted to an electrical representation thereof, stored, and then processed by the high speed image computer. After a wafer has been positioned and inspected in the macro inspection station at low magnification, it is moved by a macro-micro transport arm to the micro inspection station and a unique image previously found in the low power image is found again and used for initial alignment. An autofocus arrangment automatically focusses the objective lens to accomplish the micro inspection tests. Tests are typically carried out at a number of sites, each of which is positioned automatically by the machine.

Method and apparatus for automatic wafer inspection

An object mounting member is slideably interconnected with a guide member which provides a path between two separated fixed locations. The guide member is attached to a support member having fixed stops located between the two fixed locations. A pinion gear is fixedly attached to the shaft of a stepper motor, and a spur gear is held in an engaging relationship with said pinion gear. An eccentric arm is pivotally attached at one end to the spur gear and is driven to provide rapid motion between the two fixed locations with a rate of motion approaching zero hit nears each fixed location. The other end of the eccentric arm is pivotally attached to one end of a drive arm that is pivotally attached to the object mounting member. The drive arm includes a spring loaded member that is used to allow the object mounting member to be preloaded against a stop at each end of its travel.

Apparatus for accurately positioning an object at each of two locations

An automatic patterned wafer inspection system includes macro and micro inspection stations having optical axes that are 10 inches apart on an X-Y crossed roller stage which provides 7 inches of travel in each of two directions along two orthogonal axes. A macro-micro transport arm is pivotally interconnected with the stage and supports a turntable with a vacuum chuck centrally located thereon. The transport arm is positioned to move the wafer from a position 5 inches to the left of center of the stage (the macro axis) to a position 5 inches to the right of the center of the stage (the micro axis). Repeatability of positioning of the arms is obtained by using a spring-loaded link to drive the transport arm against a hard stop located at the left and right of the stage. The turntable is mounted so as to have an outside edge adjacent the distal end of the transport arm. A vacuum chuck for holding the wafer is attached to the turntable. A belt and pulley drive is used to rotate the turntable when it is necessary for the wafer alignment.

X-Y Stage for a patterned wafer automatic inspection system

Thermal lensing effects in a conductively cooled optically pumped laser rod are compensated by limiting the width of thermal contact between the rod surface and its supporting heat sink to an arc width of 70.degree. to 80.degree. and utilizing a simple cylindrical laser cavity mirror or mirrors. This limited heat sink contact produces nearly parallel isotherms in the rod which react with the laser beam so that it may be readily focused by a cylindrical beam focusing means in the laser optical resonator.

Optical compensation for thermal lensing in conductively cooled laser rod

A translating mechanism for accurately positioning and locking an object relative to a reference plane comprises a base plate which defines the reference plane and a platform supported parallel to the base plate for movement in a direction perpendicular to the plane of the base plate. A spring between the base plate and platform urges the latter away from the plate and an adjustment screw operably connected to the platform and to the plate permits changing of the spacing between the platform and plate against the bias of the spring. Nestable U-shaped arms pivotally connected to the plate and platform, respectively, and to each other directly slideably engage the plate and platform, and maintain parallelism therebetween during their relative movement. A flexible end wall adjacent to the platform releasably clamps the platform against the opposite end wall to lock same in any position within its range of movement. This also minimizes the load path length between platform and base.

Translating mechanism

A laser pumping assembly with a housing having a removable heat resistant glass liner or shell enclosing a pump and a laser rod comprises removable glass or quartz plates over opposite ends of the shell together with a heat absorbing shim between each end plate and an adjacent heat conductive support plate attached to the housing. The outside surface of each end plate is coated with a dielectric layer which reflects the desired wavelength of pump lamp radiation inwardly of the shell toward the laser rod and transmits undesired wavelengths to the adjacent shim. The shims are held tightly against the end plates and pass heat from the unreflected pump lamp radiation to the respective support plates for dissipation in the cooling system.

Laser pumping assembly

Growing community of inventors

Los Altos, CA, United States of America

Curt H Chadwick