Etec Systems, Inc.

Applied Materials, Inc.

Ateq Corporation

Other

Ateo Corporation

Etec System, Inc.

Paul C Allen

Timothy N Thomas

Samuel C Howells

Robin Lynn Teitzel

Marian Mankos

Douglas Earl Holmgren

Jeffrey S Sullivan

Xiaolan Chen

Morris H Green

Paul A Warkentin

Michael J Bohan

Henry Christopher Hamaker

Andres Fernandez

Steven Thomas Coyle

Michael Lawrence Rieger

Windsor Owens

Mark A Gesley

Bryan Conrad Bolt

Matthew J Jolley

Jerry Martyniuk

Allan L Sagle

Eric Christenson

Tim Thomas

Eugene Mirro

Alan J Wickstrom

Mike Bohan

Andres Fernadez

Michael Bohan

Ronald D Voisin

A multiple beam generator for use in a scanning system, wherein the generator includes an acousto-optic deflector (AOD) which during use receives a laser beam and generates a deflected beam, the deflection of which is determined by an AOD control signal; a diffractive element which generates an array of input beams from the deflected beam; and a control circuit which during operation generates the AOD control signal and varies a characteristic of the first control signal to account for errors in the scanning system.

Apparatus for multiple beam deflection and intensity stabilization

An electron beam lithography system has an electron gun including at least one laser that is operable in a first mode to generate electrons for lithography. The electron beam lithography system is operable in a second mode to regenerate the photocathode of the electron gun by application of the laser. The photocathode includes a layer of cesium telluride.

Electron beam lithography system having improved electron gun

A scanning system uses a multi-beam brush having a widely separated beams, a modulator that controls intensity of pixels in scan beams, an optical system that minimizes scan line bow at the expense of non-uniform scanning beam velocity, and a timing generator that generates a pixel clock signal having a variable period that compensates for the non-uniformity of pixel velocity. The wide separation of scan beams permits the modulator to turn beams on or off with a direction of brightening or darkening in the cross-section of the beams being opposite to the scanning direction. A novel arrangement of the beams in the brush permits a uniform indexing step size to uniformly expose an image region. In one embodiment, the timing generator includes: a source of pixel period values; a select circuit to select pixel period values for pixels, and a counter that loads a first value from the pixel period value selected for a pixel, counts for a period of time indicated by the first value, and asserts a signal marking an end of the period. An additional delay after the signal from the counter can be shorter than the period of a clock signal to the counter but also controlled by the pixel period value.

Scanning brush and method of use

The present invention provides a source of multiple beams of electrons having a desired spatial pattern, as typically used for multiple beam lithography. A source of radiation, typically ultraviolet radiation, is directed onto a modulator and from the modulator onto a photocathode. The modulator, typically a spatial light modulator, imposes a spatial pattern onto the radiation. The pattern imposed onto the radiation is transmitted to the multiple beams of electrons as such beams are generated by the photocathode. An electron beam lithography system having higher throughput than conventional single beam systems is one result. Methods of creating multiple electron beams and methods of patterning targets with such multiple beams of electrons are also described. A micromirror array is a preferred modulator. Mercury arc lamp directing ultraviolet radiation by means of the modulator onto a cesium telluride photocathode is a preferred combination of radiation source and photocathode.

Modulator driven photocathode electron beam generator

In a method of registering an image on a substrate, the substrate is placed on a substrate support and a radiation beam is directed toward the substrate. The radiation beam is reflectively diffracted to modulate the intensity of the radiation beam. The modulated radiation beam is scanned across the substrate to register an image on the substrate. In one version, the radiation beam is a laser beam which is projected onto a mask blank to form a mask.

Reflective diffraction of radiation beams for image registration

Laser pattern generator

An electron beam lithography system includes a laser for generating a laser beam, and a beam splitter for splitting the laser beam into a plurality of light beams. The intensity of the light beams is individually modulated. The light beams are of sufficient energy such that, when they impinge on a photocathode, electrons are emitted. Modulation of the light beams controls modulation of the resulting electron beams. The electron beams are provided to an electron column for focusing and scanning control. Finally, the electron beams are used to write a scanning surface, for example, using an interlaced writing strategy.

Multiple electron beam lithography system with multiple beam modulated laser illumination

An image registration apparatus has a substrate support capable of supporting a substrate, the substrate support having a support motor capable of moving the substrate support. A radiation beam source is provided that is capable of providing a radiation beam. A beam intensity modulator is also provided that has an adjustable reflective diffraction grating capable of reflectively diffracting the radiation beam to modulate the intensity of the radiation beam. A controller is also provided that is adapted to control the substrate support, radiation beam source, and beam intensity modulator to modulate and scan the radiation beam across the substrate to register an image on the substrate.

Image registration apparatus having an adjustable reflective diffraction grating and method

A lithography apparatus including both a laser beam source and an electron beam column, where the electron beam column has a support(in one embodiment a window in the column housing) having an index of refraction n. The support, having a photocathode source material disposed on its remote surface, is located in some embodiments such that the internal angle of the incident laser beam is &thgr; with respect to a line perpendicular to the remote surface. The numerical aperture of the substrate(equal to nsin &thgr;) is greater than one in one embodiment, resulting in a high resolution spot size diameter incident on the photocathode source material at the remote surface. Incident energy from the laser beam thereby emits a corresponding high resolution electron beam from the photocathode source material. Electromagnetic lens components are disposed downstream in the electron beam column to demagnify the electron beam. This apparatus allows the continuously decreasing minimum feature dimension sizes for semiconductor electron beam lithography.

Electron beam column using high numerical aperture photocathode source illumination

An acousto-optic modulator for use with a multi-channel laser beam system, for instance, is of conventional structure except that two different RF (radio frequency) signals drive the modulator. These signals each produce at least one output beam as diffracted by the modulator body. These two beams are angularly and spatially separated. One of the sets of beams is incident upon a beam stop, and therefore is not used for writing. Only the other set of beams, driven by the other of the frequencies, performs the actual writing. The optical stop in addition to blocking one of the sets of diffracted beams also blocks the transmission of the zero order (undiffracted) beam. The sum of the load power of the signals at the two frequencies is kept approximately constant, thereby maintaining a constant thermal condition within the modulator.

Thermally balanced acousto-optic modulator

A precision printing system uses multiple scan beams that an acousto-optic modulator (AOM) separately modulates. An array of optical elements such as dove prisms separately rotates each of the beams about a central ray of the beam to eliminate blurred edges, skew, and variations in line thickness caused by the direction of propagation of acoustic waves in the AOM being at an angle to a scan direction. In particular, the amount of rotation is selected so that in the final image the direction in which illumination progresses across a cross-section of a beam is in a direction opposite the scan direction. A method of making the array includes attaching rods to a flat, grinding or polishing the combination of the rods and flat to form three planar regions that correspond to facets on prisms. Removing the rods/prisms from the flat. Using photolithography and etching to form grooves in a substrate, and a mounting the rods/prisms in the grooves on the substrate. Integrated circuit processing techniques that control the spacing, widths, and depths of the grooves provide precise control of critical alignment of the prisms.

Multi-beam scanner including a dove prism array

A laser pattern generator for semiconductor mask making or direct writing of features on a semiconductor wafer uses a pulsed laser source to achieve high power and short wavelength (e.g. 263 nm or less) radiation, for writing very small-sized features. The laser pulse frequency is either synchronous or asynchronous to the writing grid of the features being written, in various embodiments.

Short wavelength pulsed laser scanner

A small field scanning photolithography system uses opposing motion of a reticle and a blank to compensate for image reversal by a projection system such as a conventional Wynne-Dyson optical system which forms a reverted image on a blank. The reticle has a reverted pattern. During scanning, the reticle moves along a reverted axis in a direction opposite the direction in which the blank moves. The opposing motions can either expose a stripe on the blank or index the reticle and blank for exposure of a next stripe. In one embodiment of the invention, the reticle and blank are on independently movable precision air bearing stages. Typically, the blank and reticle move together perpendicular the reverted axis and in opposite direction along the reverted axis. The stages can move the reticle and blank different amounts to correct for shrinkage and temperature changes which cause the size of the reticle and blank to differ.

Scanning lithography system with opposing motion

Magnification correction for small field scanning of large blanks is provided by adding magnification adjusting elements (lenses) to a double pass Wynne-Dyson lens or other type of one-to-one projection lens. The magnification adjusting optical elements includes two pairs of low power lenses, one associated with each of the input and output prisms of a Wynne-Dyson lens. Movement of the magnification adjusting optics provides positive or negative magnification as needed to correct for any expansion or compaction of the blank relative to the reticle (mask) and hence maintain alignment. Further magnification correction is provided by a small velocity relative movement between the reticle and the blank by means of a secondary stage in the scan direction. This corrects for any alignment error in the scan direction and may be used independently of the optical correction technique with any type of projection lens.

Magnification correction for small field scanning

A small field scanning photolithography system has a double pass Wynne-Dyson optical system which provides an erect, non-reverted, unmagnified image. An optical path through the system passes from an object, reflects off an input reflector, passes through a first quadrant of a lens, reflects off a concave mirror, passes through a second quadrant of the lens into folding optics where an intermediate image forms, passes from the folding optics through a third quadrant of the lens, reflects off the concave mirror a second time, passes through a fourth quadrant of the lens, and finally reflects off an output reflector to a plane where a final image forms. Typically, the input and output reflectors and the folding optics are prisms. A field stop may be provided in the folding optics where the intermediate image forms. Magnification adjusting optics can be added to the input and output prisms or to the folding optics. The magnification adjusting optics forms two narrow meniscus air gaps which are equal size for unity magnification. Narrowing one air gap and widening the other air gap changes magnification slightly.

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Beaverton, OR, United States of America

Paul C Allen