Kla Instruments Corporation

Hermes Microvision, Inc. (taiwan)

Anil A Desai

Curt H Chadwick

Alan D Brodie

Chung-Shih Pan

Eric Munro

Richard R Simmons

John McMurtry

April Dutta

Dennis G Emge

Henry Pearce-Percy

David J Clark

Lee H Veneklasen

J Kirkwood Rough

John S Taylor

John D Greene

Ralph T Johnson

Yi Xiang Wang

Chetana Bhaskar

Dan Meisburger

Timothy L Hutcheson

Jack Y Jau

Barry Becker

Paul Wieczorek

Kirkwood Rough

Surendra Lele

Chun C Lin

Yen-Jen Oyang

Dave E Smith

Chris Kirk

Zhong-Wei Chen

Dan Meisberger

Leslie A Honfi

Hoi T Nguyen

Ming-Yie Ling

Hans Dohse

Ray Paul

Mike Robinson

David E Smith

Dean Walters

Sam Wong

A method for inspecting a semiconductor wafer using an SEM having a nominal focal plane and operable for guiding a beam. The SEM having a stage movable in each of an X-, Y-, and Z-direction, including moving the SEM stage in the XY-direction to a first location for inspection, optically sensing the location of the top surface of an area in relation to the focal plane of the stage, adjusting the position of the stage in the Z-direction so that the top surface of the area is substantially at the focal plane, inspecting the areas, and moving the stage in the XY-direction to the next location such that the next area is under the SEM beam for inspection. The Z-stage using a non-contact optical sensor to provide feedback to drive a plurality of piezoelectric actuator to move the wafer to the focal plane.

Method and system of using a scanning electron microscope in semiconductor wafer inspection with Z-stage focus

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

Electron beam inspection system and method

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.

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 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

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San Jose, CA, United States of America

Anil A Desai