Nikon Corporation

Nikon Precision Incorporated

Nikon Research Corporation of America

Nikon Corporation of Japan

Michael R Sogard

Andrew J Hazelton

Daniel Gene Smith

Douglas C Watson

Martin E Lee

Alton Hugh Phillips

David Michael Williamson

John H McCoy

Denis F Spicer

W Thomas Novak

David P Stumbo

Akikazu Tanimoto

Eric Peter Goodwin

Naoyuki Kobayashi

Bausan Yuan

Kyoichi Suwa

Mark K Takita

Saburo Kamiya

Masahiko Okumura

Kiyoshi Uchikawa

John K Eaton

Yosuke Shirata

Alireza Jabbari

Michael Kovalerchik

Motofusa Ishikawa

Christopher T Black

An apparatus and method for measuring thermo-mechanically induced reticle distortion or other distortion in a lithography device enables detecting distortion at the nanometer level in situ. The techniques described use relatively simple optical detectors and data acquisition electronics that are capable of monitoring the distortion in real time, during operation of the lithography equipment. Time-varying anisotropic distortion of a reticle can be measured by directing slit patterns of light having different orientations to the reticle and detecting reflected, transmitted or diffracted light from the reticle. In one example, corresponding segments of successive time measurements of secondary light signals are compared as the reticle scans a substrate at a reticle stage speed of about 1 m/s to detect temporal offsets and other features that correspond to spatial distortion.

Apparatus and methods for measuring thermally induced reticle distortion

A new and useful illumination device, e.g. for a lithographic optical imaging system, is provided, and comprises a mirror array located between a radiation source and an illumination pupil. Each mirror element of the mirror array is individually steerable (controllable), and the polarization state of light from each mirror element of the mirror array can be selectively controlled, so that the illumination pupil can be filled with a distribution of light that is selectively controlled.

Illumination device for optimizing polarization in an illumination pupil

The subject fluid gauges measure actual position of a workpiece relative to a target position. A gauge body that is positionable relative to the workpiece and that includes multiple differential-pressure (DP) sensors has a measurement channel and respective reference channels. Each DP sensor measures, over a respective individual dynamic pressure range, a differential pressure established by a respective fluid flow in the measurement channel relative to a fluid flow in a respective reference channel. The dynamic pressure ranges of the DP sensors substantially overlap each other. A controller is connected to and monitors the DP sensors. The controller is configured to select, for obtaining a differential pressure indicative of the position of the workpiece, a DP sensor sensing the smallest magnitude of DP.

Fluid gauges comprising multiple differential pressure sensors

An exemplary thermally regulated component is an optical element or chuck for holding an optical element, or a stage for same, or combination thereof. The component has first and second heat-transfer zones. The first has a first component surface that receives a heating influence such as incident electromagnetic radiation. The second has a second component surface. A conduit circuit extends in the component serially through the first and second heat-transfer zones, back to the first heat-transfer zone, and contains an electrically conductive liquid (e.g., liquid metal). A vibration-free pump (e.g., MFD pump) coupled to the conduit circuit induces flow of the liquid through the circuit. A heat-exchanger is in thermal contact, but not actual contact, with the second component surface. Thus, heat delivered to the second heat-transfer zone by the liquid flowing in the conduit circuit flows from the second component surface to the heat-exchanger. The pump can be powered by a periodically remotely charged power source.

Thermal regulation of vibration-sensitive objects with conduit circuit having liquid metal, pump, and heat exchanger

A lithographic projection apparatus includes a projection system and a liquid confinement member extending along a boundary of a space under the projection system. The liquid confinement member has (i) a first opening facing downwardly via which a liquid is removed from a gap to be formed under the liquid confinement member, and (ii) a second opening facing downwardly via which fluid is removed from the gap to be formed under the liquid confinement member, the second opening being located radially outward of the first opening with respect to the space. The liquid in the space covers a portion of an upper surface of a substrate and the substrate is exposed through the liquid in the space.

Environmental system including vacuum scavenge for an immersion lithography apparatus

A liquid immersion lithography apparatus includes an optical assembly having a last optical element, a first outlet facing downward, via which an immersion liquid is released, a first inlet via which the immersion liquid is drawn, and a containment member arranged to surround a last portion of the optical assembly. The containment member has (i) a second inlet facing downward, which is arranged radially-outwardly from the first outlet with respect to a space under the last optical element and via which fluid is removed from a gap formed under the containment member, and (ii) a second outlet facing downward, via which gas is supplied to the gap formed under the containment member, the second outlet being arranged radially-outwardly from the second inlet with respect to the space.

Apparatus are disclosed for measuring the position of an object surface along an axis. An exemplary apparatus has at least one actuator coupled to a fixed member such as a metrology frame. At least one analog proximity sensor is coupled to the at least one actuator. The at least one actuator is controllably operated to position the at least one proximity sensor at a fixed distance along the axis from a surface that is fixed relative to the fixed me+mber. A controller, coupled to the actuator and to the proximity sensor, is configured to compute a position of the object surface along the axis based on a known location of the fixed surface along the axis, the fixed distance from the fixed surface, and position signals from the at least one proximity sensor.

Position-measurement systems

In a lithography tool used in fabricating microelectronic devices, autofocus (AF) systems provide automatic image focusing before making exposures. To reduce production of erroneous results based on interaction of a beam of AF light with certain regions on lithographic substrates, a subject AF device has a sending unit and a receiving unit. The sending unit directs an AF light beam to the substrate, and the receiving unit receives AF light reflected from the substrate. The receiving unit has a system photodetector and a patterned optical element that receives AF light from the substrate and transmits a selected diffraction order(s) of said light. The system photodetector senses light of the selected diffraction order of reflected AF light while at least one additional photodetector detects divergent reflected AF light. Substrate areas exhibiting unusual amounts of divergent light may indicate a focus-error condition. The AF systems can be configured as fringe-projection or slit-projection AF systems.

Apparatus and methods for reducing autofocus error

An exemplary method involves, in a system comprising a tool that performs a task on a workpiece, a method for determining displacement of the workpiece relative to the tool. Respective displacements of loci of at least a region of the workpiece are mapped using a Goos-H&#xe4;nchen-insensitive (GH-insensitive) displacement sensor to produce a first set of physical displacement data for the region. Also mapped are respective displacements, from the tool, of the loci using a GH sensitive sensor to produce a second set of optical displacement data for the region. Goodness of fit (GOF) is determined of the second set of data with the first set. According to the GOF, respective GH-correction (GHC) coefficients are determined for at least one locus of the region. When measuring displacement of the at least one locus in the region relative to the tool, the respective GHC coefficient is applied to the measured displacement to reduce an error that otherwise would be present in the measured displacement due to a GH effect.

Methods and devices for reducing errors in Goos-H&#xe4;nchen corrections of displacement data

An immersion lithography apparatus includes (i) an optical assembly including an optical element, and configured to project a beam onto a substrate through an immersion liquid; (ii) a containment member that surrounds a path of the beam; and (iii) a stage on which the substrate is held, the substrate on the stage being moved below and spaced from a bottom surface of the containment member. The containment member includes: (1) a nozzle outlet via which water as the immersion liquid is released, (2) a recovery channel via which the immersion liquid is recovered from a gap between the containment member and the substrate and/or the stage, and (3) a fluid channel via which water is released to the gap between the containment member and the substrate and/or the stage, the fluid channel being provided radially inward of the recovery channel.

Environmental system including a transport region for an immersion lithography apparatus

A liquid immersion exposure apparatus includes an optical assembly having a final optical element, from which exposure light is projected through immersion liquid filling an optical path of the exposure light under the final optical element, a containment member surrounding a tip portion of the optical assembly, and a movable stage to hold a substrate and having an upper surface around the held substrate. An apparatus frame supports the optical assembly and the containment member, and an optical mount isolator, which has an actuator, isolates the optical assembly from vibrations of the apparatus frame. A first inlet of the containment member faces at least one of the substrate and the stage and collects fluid from a gap between the containment member and the at least one of the substrate and the stage. A gas supply outlet of the containment member supplies gas to the gap.

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Menlo Park, CA, United States of America

Michael R Sogard