International Business Machines Corporation

Nikon Corporation

Christopher Frederick Robinson

Daniel A Corliss

Werner Stickel

Michael S Gordon

William A Enichen

David V Horak

Steven J Holmes

Charles W Koburger, Iii

Ekmini Anuja De Silva

Karen Elizabeth Petrillo

Kurt R Kimmel

Luciana Meli Thompson

Cody John Murray

Luciana Meli

Scott A Messick

Wayne Martin Moreau

Scott David Halle

Rodney A Kendall

Paul F Petric

James D Rockrohr

Robert S Young

Richard C Johnson

Shane D Bryant

Chumeng Zheng

Kelly Bronson

Jon E Lieberman

Techniques for using open frame (E0) exposures for lithographic tool track/cluster monitoring are provided. In one aspect, a method for monitoring a lithographic process includes: performing open frame exposures E0 of at least one wafer coated with a photoresist using a photolithography tool; baking and developing the at least one wafer; performing a defect inspection of the at least one wafer to generate a haze map; grouping haze data from the haze map; and analyzing the haze data to identify a maximum E0 response dose E'.

Using E0 exposures for track/cluster monitoring

A method of controlling a gas mixture for a laser includes receiving as an input one or more of a plurality of concentration values. Each of the concentration values respectively corresponds to a constituent of a plurality of constituents of air. In the method, a blend of the plurality of constituents of air is generated based on the received one or more of the concentration values. The method also includes determining whether the blend of the plurality of constituents of air is within a threshold range for a ratio of the concentration values for the plurality of constituents of air. A flow of the blend of the plurality of constituents of air is controlled to be routed through an output circuit for use as the gas mixture for the laser following a determination that the blend of the plurality of constituents of air is within the threshold range.

Personnel-tolerant carbon dioxide beamline variation reduction

Techniques for lithography process delay characterization and effective dose compensation are provided. In one aspect, a method of analyzing a lithography process includes: applying a photoresist to a wafer; performing a post-apply bake of the photoresist; patterning the photoresist with sequences of open frame base line exposures performed at doses of from about 92% E0 to about 98% E0, and ranges therebetween, at multiple fields of the wafer separated by intervening programmed delay intervals, wherein E0 is the photoresist dose-to-clear; performing a post-exposure bake of the photoresist; developing the photoresist; performing a full wafer inspection to generate a grayscale map of the wafer; and analyzing the grayscale map to determine whether the intervening programmed delay intervals had an effect on the open frame base line exposures during the lithography process. Exposure dose compensation can then be applied to maintain a constant effective dose.

Lithography process delay characterization and effective dose compensation

Methods for determining unintentional exposure dose such as flare or out-of-band radiation of a lithography tool are provided. The methods generally include performing a series of open frame exposures with the lithography tool on a substrate having a photoresist therein to produce a primary array of controlled exposure dose blocks in the photoresist. Secondary exposure blocks are embedded within the primary array. The resultant open frame images are scanned with oblique light and the light scattered from the substrate surface captured. A haze map is created from a background signal of the captured scattered light data and converted to a graphical image file. Analyzing the graphical image file can be used to correlate any localized changes in the effective dose of the primary exposure array to the impact of secondary exposure blocks to characterize flare or out-of-band radiation associated with the exposure dose.

Lithographic dose characterization

Systems, methods and computer program products generally include a vector by vector subtraction method per wafer. A first layer is exposed to form a pattern image on a wafer and the overlay data of alignment registration marks at multiple locations relative to alignment registration marks of a baseline reference are measured. The first layer is then reworked and exposed to form the same pattern image and the overlay data of alignment registration marks at multiple locations relative to alignment registration marks of a first layer are measured. The overlay data of the reworked first layer is subtracted from the overlay data of the first layer to provide an overlay difference at each of the multiple locations. The overlay difference is converted to a pre-correction factor of a magnitude opposite that of the overlay difference and is applied to exposure of a second layer provided on the first layer.

Baseline overlay control with residual noise reduction

Embodiments are directed to a method and system for determining effective dose of a lithography tool. The method includes performing a series of open frame exposures with the lithography tool on a substrate to produce a set of controlled exposure dose blocks in resist, and then baking and developing the exposed substrate. The method further includes scanning the resultant open frame images with oblique light and capturing the light scattered from the substrate surface. The method further includes creating a haze map from the background signal of the scattered light data, converting the haze map to a graphical image file, and analyzing the graphical image file to determine effective dose of the lithography tool, wherein a brightness of the graphical image file is related to effective dose of the lithography tool.

Determination of lithography effective dose uniformity

An article including a microelectronic substrate is provided as an article usable during the processing of the microelectronic substrate. Such article includes a microelectronic substrate having a front surface, a rear surface opposite the front surface and a peripheral edge at boundaries of the front and rear surfaces. The front surface is a major surface of the article. A removable annular edge extension element having a front surface, a rear surface and an inner edge extending between the front and rear surfaces has the inner edge joined to the peripheral edge of the microelectronic substrate. In such way, a continuous surface is formed which includes the front surface of the edge extension element extending laterally from the peripheral edge of the microelectronic substrate and the front surface of the microelectronic substrate, the continuous surface being substantially co-planar and flat where the peripheral edge is joined to the inner edge.

Microelectronic substrate having removable edge extension element

An article including a microelectronic substrate is provided as an article usable during the processing of the microelectronic substrate. Such article includes a microelectronic substrate having a front surface, a rear surface opposite the front surface and a peripheral edge at boundaries of the front and rear surfaces. The front surface is a major surface of the article. A removable annular edge extension element having a front surface, a rear surface and an inner edge extending between the front and rear surfaces has the inner edge joined to the peripheral edge of the microelectronic substrate. In such way, a continuous surface is formed which includes the front surface of the edge extension element and the front surface of the microelectronic substrate, the continuous surface being substantially co-planar and flat where the peripheral edge is joined to the inner edge.

Electron beam lithography tool image quality evaluating and correcting including a test pattern with a repeated test pattern cell, an evaluation method and correction program product are disclosed. The test pattern cell includes a set of at least three elongated spaces with each elongated space having a different width than other elongated spaces in the set such that evaluation of a number of space widths in terms of tool image quality and calibration can be completed. The evaluation method implements the test pattern cell in a test pattern in at least thirteen sub-field test positions across an exposure field, which provides improved focus and astigmatism corrections for the lithography tool. The program product implements the use of corrections from the at least thirteen sub-field test positions to provide improved corrections for any selected sub-field position.

Lithography tool image quality evaluating and correcting

Test patterns and a method for evaluating and adjusting the resolution of an electron beam lithography tool. The test patterns include multiple feature patterns that are repeated throughout the test pattern. Each feature pattern can be interleaved with horizontal and/or vertical line patterns that facilitate cleaving of a test substrate for three dimensional analysis of the developed image. Further, each feature pattern can comprise multiple sub-patterns. Each sub-pattern includes at least one feature having a size that varies from less than a nominal resolution limit of the lithography tool to greater than the nominal resolution limit. The lithography tool resolution can be evaluated by exposing a test pattern on a resist coated substrate, and analyzing the developed image.

Lithography tool test patterns and method

An electron beam system employs a non-saturating detector for measuring total beam current that comprises a thin membrane of only a few microns thickness placed before a detector and separated from the detector by a drift space of about 10 mm, so that electrons in the beam are not absorbed to any significant extent, but are scattered transversely to spread the beam and avoid local saturation of the detector.

Electron scatter in a thin membrane to eliminate detector saturation

A method of aligning elements of an electron beam beam tool such as an electron beam projection lithography tool utilizes a detector such as a pinhole and scintillator over which an image is rastered to provide a real-time display of a projected image at a target plane. A shaping aperture is projected and the detector centered thereon. A reticle sub-field image is then centered on and aligned with the image of the shaping aperture and the compound image thus formed is rotated using deflectors. The compound image is then aligned with movement of a translation device at the target plane using lenses and compound image orientation is corrected by electrical or mechanical rotation of the deflectors. Sub-field size can then be adjusted and any observed further rotation of the compound image may be corrected by reiteration of rotation adjustment with lenses and deflectors, in sequence.

Method for aligning electron beam projection lithography tool

Proximity (exposure dose) effects and/or local Coulomb (space charge defocussing) effects, both dependent on local pattern density of exposed areas, are simultaneously compensated in a charged particle beam projection device or tool by a projection reticle having an apertured weakly scattering membrane with selective strongly scattering regions between the apertures in the membrane. A reticle so constructed provides at least three independent exposure dosage levels that can be mixed to provide a wide range of exposure levels with high contrast. The more weakly the electrons are scattered (in the extreme, the electrons are not scattered at all through apertures), the greater the number that pass through a given beam contrast aperture, the higher the corresponding dose received at the target plane and the more space charge is contained in the beam bundle. Therefore, to compensate for the proximity effect (i.e. provide dose boost) and the local Coulomb effect (i.e. provide additional space charge) regions with reduced scattering characteristics are employed. Use of a hybrid doped resist allows exposure corresponding to an intermediate exposure dose in a preferred variant implementation exploiting the three dosage levels developed.

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Hyde Park, NY, United States of America

Christopher Frederick Robinson