International Business Machines Corporation

Nikon Corporation

Timothy R Groves

Rodney A Kendall

Maris A Sturans

John George Hartley

Hans C Pfeiffer

Werner Stickel

Henry Ignatius Smith

Steven D Golladay

Paul F Petric

James D Rockrohr

Samuel Kay Doran

Mark L Schattenburg

William A Enichen

James Gregory Goodberlet

Juan R Maldonado

Henri A Khoury

George J Giuffre

Rainer Butsch

Juan Ferrera

Richard D Moore

Douglas G Cullum

Mark K Mondol

Fine positioning of a shaped or patterned charged particle beam without use of intrusive fiducial marks is achieved by providing a dithered shadow pattern, preferably in the form of a grid, within the shaped or patterned charged particle beam. Light output from fiducial marks preferably formed of a scintillating material is reduced when the dithered shadow pattern is incident on some or all of the fiducial marks. The timing of the incidence of the shadow pattern on fiducial marks indicates the position of the shaped or patterned charged particle beam such that correction of the beam position on the target can be corrected to a small fraction of system resolution. The dither pattern and repetition period is chosen to avoid interference with uniformity of beam illumination of the target. Feedback of position error thus provides phase locked position correction in real time and is suitable for mask making since the fiducial marks are not intrusive.

Spatial phase locking with shaped electron beam lithography

A scattering target for use in a particle beam system is formed from a grid of gold on a substrate of carbon, with an intermediate smoothing layer (e.g. copper) on the carbon to provide a surface sufficiently smooth to provide an adequate target. An optional bonding layer may be used to improve adhesion between the gold and the smoothing layer.

Calibration target for electron beams

A method for improving image fidelity on a resist. The method adjusts the intensity distribution of the electron beam such that the feature size at the edges and the center of a subfield have a same width &ldquo;w&rdquo;. This is accomplished by intentionally increasing the incident intensity where the images are small (more pronounced blurring), and intentionally decreasing the incident intensity where the images are large (less pronounced blurring). This can be achieved, for example, by maintaining a cathode temperature profile which increases or decreases radially by an appropriate amount.

Compensation of within-subfield linewidth variation in e-beam projection lithography

A method of operating multiple beam direct write e-beam system employs a set of miniature beam writing modules acting in parallel, each of which employs the combination of a uniform magnetic field and a uniform parallel electric field to form an image of a low-brightness electron emitting surface and also to modify the shape of an initially square beam, thereby producing a set of separately and independently modified beams; the modified beams are deflected in parallel by the same magnetic field and a uniform transverse electric field to cover a desired area; emitters, beamshaping deflection electrodes and fine-deflection electrodes are formed by microlithographic techniques.

Method for writing a pattern using multiple variable shaped electron beams

A multiple beam direct write e-beam system employs a set of miniature beam writing modules acting in parallel, each of which employs the combination of a uniform magnetic field and a uniform parallel electric field to form an image of a low-brightness electron emitting surface and also to modify the shape of an initially square beam, thereby producing a set of separately and independently modified beams; the modified beams are deflected in parallel by the same magnetic field and a uniform transverse electric field to cover a desired area; emitters, beamshaping deflection electrodes and fine-deflection electrodes are formed by microlithographic techniques.

Distributed direct write lithography system using multiple variable

A multiple beam direct write e-beam system employs a set of miniature beam writing modules acting in parallel, each of which employs the combination of a uniform magnetic field and a uniform parallel electric field to form an image of a low-brightness electron emitting surface and also to modify the shape of an initially square beam, thereby producing a set of separately and independently modified beams, in which emitters, beamshaping deflection electrodes and fine-deflection electrodes are formed by microlithographic techniques.

Multiple variable shaped electron beam system with lithographic structure

Across chip line width variations and other repetitive deviations from the design pattern desired in E-Beam lithography are compensated for by examining each of the regions (i.e., frames, stripes, etc.) of a patterned substrate, determining the amount of deviation for each region, and using the determined regional deviation as a local bias when patterning subsequent substrates. Thus, the E-Beam lithography tool will utilize both global and local biases in order to produce new patterned substrates which lack the deviations found when local bias was not applied. In this way, the root cause of the deviation does not need to be determined. The local bias can be applied directly by modifying the E-Beam lithography system tool commands to provide for patterning wider or thinner lines or to provide for greater or lesser exposure time. Alternatively, the local bias can be applied by varying the emission current of the electron gun for different regions of the substrate.

Emulation methodology for critical dimension control in E-Beam

X-ray lithography is used in the fabrication of very large scale integrated circuits. Optical lithography techniques are used to create a preliminary mask with coarse features in the preparation of a high resolution x-ray mask. The E-beam tool may register the location of the E-beam relative to the optically written coarse features. This helps the tool to navigate according to the location of specific features.

High accuracy fabrication of X-ray masks with optical and E-beam

An electron beam nanometer-level metrology tool includes an ambient temperature electron source and a movable stage for mounting a workpiece. The stage is adapted to position the workpiece's surface in a beam interrogation region. Electrostatic focus lenses convert electrons emitted by the electron source into a beam with a focal point that is positioned in the beam interrogation region. The lenses cause the electron beam to traverse a path that is generally orthogonal to the workpiece surface. Along the beam path are positioned upper and lower electrostatic deflection plates which are connected to an adjustable voltage source that applies ganged, opposite-sense d/c potentials thereto. Those potentials enable a scanning of the beam across the beam interrogation region while the beam remains substantially orthogonal to the workpiece surface, thereby enabling more accurate measurements of surface features. Within the metrology tool, all beam control surfaces are electrostatic so as to minimize power dissipation and temperature differentials.

Electron beam nano-metrology system

A two staqge, electron beam projection system includes a target, a source of an electron beam and means for projecting an electron beam towards the target with its upper surface defining a target plane. A magnetic projection lens has a principal plane and a back focal plane located between said means for projecting and the target. The means for projecting provides an electron beam directed towards the target. First stage means provides deflection of the beam from area to area within a field. Second stage means provides for deflection of the beam for providing deflection of the beam within an area within a field. The beam crossing the back focal plane produces a telecentric condition of the beam in the image plane with the beam substantially normal to the target plane from the principal plane to the target plane. The magnetic projection lens includes a magnetic structure providing for magnetic compensation positioned within the bore of the projection lens, which produces a compensating magnetic field substantially proportional to the first derivative of the axial magnetic projection field. The axial magnetic projection field provides substantially a zero first derivative of the axial magnetic projection field in the vicinity of the target. The projection system projects on the target plane from the projection system as deflected by the upper and lower stages, at all times maintaining the telecentric condition of the electron beam at the target plane throughout the entire range of deflection of the beam, assuring minimum errors due to target height variations.

Telecentric sub-field deflection with vail

An electrostatic deflection plate for charged particle beam systems is formed of a planar semiconductive substrate having a conductive region at the substrate surface. The conductive region is diffused or implanted into the body of the substrate, or one or more conductive layers are deposited upon the substrate surface. The substrate material is preferably silicon and the diffused or implanted region is formed of a nonmagnetic, nonoxidizable metal such as gold or platinum. The deposited conductive region may be formed of a single layer of these or similar metals, one or more conductive underlayers with a nonmagnetic, nonoxidizable overlayer, a single or multilayer structure with a conductive oxide on the outermost layer, or a metallo-organic compound which forms a conductive layer during following heat treatment. The deflection plates are fabricated using conventional semiconductor processes and form durable structures which minimize eddy current effects.

Growing community of inventors

Poughkeepsie, NY, United States of America

Timothy R Groves