International Business Machines Corporation

Massachusetts Institute of Technology

Juan Ferrera

Henry Ignatius Smith

Hermann A Haus

Michael Hong Lim

John George Hartley

Mark L Schattenburg

Timothy R Groves

James Gregory Goodberlet

Thomas E Murphy

Mark K Mondol

Jay N Damask

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 wavelength-selective optical switch having a first input port for accepting a plurality of copropagating optical channels, each of the channels having a distinct wavelength band. The optical switch includes first and second output ports. A wavelength-selective optical filter is connected to receive the copropagating optical channels from the first input port to extract a selected one of the channels while allowing the remaining channels to copropagate to the first output port. An interferometric switch is connected to receive the selected extracted channel; the interferometric switch includes a controller for controlling propagation of the selected extracted channel to either the second output port, the optical filter, or both. The optical filter is connected to receive from the interferometric switch an optical channel to be combined with the remaining copropagating channels and all directed to the first output port. In a first control state of the controller, the interferometric switch is adapted to direct the selected extracted channel to the optical filter, while in a second control state of the controller, the interferometric switch is adapted to direct the selected extracted channel to the second output port. A second input port can be provided for accepting an injected optical channel having a wavelength band corresponding to the wavelength band of the selected extracted channel. This second input port is connected to direct the injected optical channel to the interferometric switch. In this scenario, the interferometric switch is adapted, in the second control state of the controller, to direct the injected channel to the optical filter, and is adapted to direct the injected channel, in a first control state of the controller, to the second output port.

Wavelength-selective optical add/drop switch

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Fremont, CA, United States of America

Juan Ferrera