Massachusetts Institute of Technology

Other

International Business Machines Corporation

James Gregory Goodberlet

Henry Ignatius Smith

Jeffrey Todd Hastings

Feng Zhang

Rajesh Menon

James G Fujimoto

David J Carter

Dario Gil

John George Hartley

Mark L Schattenburg

Timothy R Groves

Peter A Schulz

Juan Ferrera

Mark K Mondol

Alphonse George Goodberlet

Vemura H S Moorthy

Jyhpyng Wang

A method or system of spatial-phase locking a beam used in maskless lithography provides a fiducial grid with a single spatial-period, the fiducial grid being rotated at an angle with respect to a direction of scanning the beam; detects a signal generated in response to the beam being incident upon the fiducial grid; determines frequency components of the detected signal; and determines a two-dimensional location of the beam from phases of two determined fundamental frequency component. The method or system further determines a size of the beam from relative amplitudes of the determined fundamental and harmonic frequency components and/or determine a shape of the beam from relative amplitudes of the determined fundamental and harmonic frequency components. The method or system corrects a deflection of the beam in response to the determined two-dimensional location, and/or adjusts the size of the beam in response to the determined size, and/or adjusts the shape of the beam in response to the determined shape. If the method or system spatial-phase locks a plurality of beams used in maskless lithography, a fiducial grid with a varying spatial-period is utilized. In the plural beam method or system, the frequency components for each beam are determined using frequency-division multiplexing.

Spatial-phase locking of energy beams for determining two-dimensional location and beam shape

A method is disclosed for forming an array of focusing elements for use in a lithography system. The method involves varying an exposure characteristic over an area to create a focusing element that varies in thickness in certain embodiments. In further embodiments, the method includes the steps of providing a first pattern via lithography in a substrate, depositing a conductive absorber material on the substrate, applying an electrical potential to at least a first portion of the conductive absorber material, leaving a second portion of the conductive material without the electrical potential, and etching the second portion of the conductive material to provide a first pattern on the substrate that is aligned with the first portion of the conductive absorber material.

System and method for fabrication and replication of diffractive optical elements for maskless lithography

This invention enables high-resolution, high-precision motion control at low cost. A novel flexure-beam motion-reducing actuator is incorporated into an XY&#xd8; positioning stage to enable rigidly stable positioning of any object with sub-10-nanometer linear-positioning precision and sub-0.1-microradian rotary-positioning precision. The actuator's output element moves in the same direction as its input element. A single actuator enhances the resolution and precision of any motion-control drive mechanism by a factor as much as 50 or more, and a cascaded pair of actuators provide enhancement factors greater than 1000. In one embodiment, the enhancement factor is adjustable manually. The actuator and stage are useful for optical, lithographic and scanning probe applications.

Flexure-beam actuator and stage for micro- and nano-positioning

An integrated micro-photomultiplier is disclosed which employs sub-micron-wide channels for electron amplification. These channels are created with standard lithographic and planar-fabrication techniques, and sealed with a vacuum-deposition process. A photocathode, continuous dynode, anode and signal-collector are fabricated along the channels. This photomultiplier design obviates the needs for through-substrate etching, and mechanical assembly of separate layers. Because large-scale-integration techniques can be used to fabricate multiple micro-photomultipliers, significant reductions in device cost and size are expected. The integrated micro-photomultiplier is useful for high-speed, low-light-level optical detection, and may find applications in optical communications, visible or infrared imaging, and chemical or biological sensing.

Fully-integrated in-plane micro-photomultiplier

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 very-high-density memory device which utilizes a scintillating medium for data storage. In one mode, the device operates as a read-only-memory (ROM) unit. In another mode, the device functions as a one-time-write (OTW) and then read-only-memory unit. In an exemplary embodiment, information is read at high data rates from a rotating data-storage disk or cylinder with an electron beam and sensitive photodetector. Two methods of following the data tracks on the storage medium are provided. Masks are provided for use in patterning the data or data tracks. These masks may also be used to pattern very-high-density media for other applications such as magnetic memory and optical near-field memory. A method of patterning radially-periodic structures using interferometric lithography is also provided.

Very-high-density memory device utilizing a scintillating data-storage medium

A scintillating fiducial pattern, and methods of fabricating and using same, on a substrate or a resist/substrate composite, where the scintillating fiducial pattern is used in a spatial referencing scheme. The invention includes the use of a scintillating fiducial pattern as alignment or reference marks on a resist/substrate composite, into which a pattern or feature is to be defined. The invention includes the use of a scintillating fiducial in a mask alignment scheme. The invention includes the use of a scintillating fiducial grid or grating in conjunction with an energy beam locating method, or spatial-phase-locked electron-beam lithography. Spatial referencing to the scintillating fiducial grid, or grating, may be implemented with a delay-locked loop, which locks the phase of a signal from the scintillating grid, or grating, to the phase of a known signal. The invention includes the use of a scintillating fiducial grating, or grid, or the like, in conjunction with energy beam locating, to pattern a distortion-free grating or grid. The invention includes the use of an optical or combined photon/electron detection scheme to detect the scintillating fiducial pattern or a signal from the scintillating fiducial pattern.

Scintillating fiducial patterns

This invention relates to a tunable solid-state laser which generates ultrashort output pulses with continuous wave pumping. The device includes a lasing medium having a gain cross section of 10.sup.-18 cm.sup.2 or less and mode beating characteristics, which lasing medium is mounted in a laser cavity. A continuous wave pumping beam is applied to the lasing medium causing an output, a portion of which is applied to an intensity dependent nonlinear cavity. The output applied to the nonlinear cavity is retroreflected back through the cavity and is interferometrically combined with the laser output. The relative lengths of the cavities are initially selected such that phase changes caused by the nonlinear medium result in substantially maximum enhancement of intensity peaks of the laser output, causing self starting of pulsed operation. Once pulsed operation is achieved, the cavity lengths may be adjusted to optimize interferometric addition of peak outputs and interferometric cancellation of pulse wings, resulting in a laser output formed of ultrashort pulses. For preferred embodiments, the laser is a titanium sapphire laser, and the nonlinear cavity contains a single mode optical fiber which induces intensity dependent phase changes in an optical signal passing therethrough. A feedback circuit is preferably provided to stabilize pulse operation.

Growing community of inventors

Melrose, MA, United States of America

James Gregory Goodberlet