Massachusetts Institute of Technology

Erik H Anderson

Henry Ignatius Smith

Mark L Schattenburg

First and second coherent beams illuminate a common area on an exposure station. A phase detector senses the relative phase between the first and second beams to provide a control signal. There is at least one phase shifter in the path of at least one of the coherent beams. The control signal is coupled to the phase shifter to adjust the phase imparted thereby so that the relative phase between the first and second coherent beams is substantially constant.

Holographic lithography

A method of monitoring the travel of a beam of energy on a substrate having a fiducial pattern rigidly fixed relative to the substrate, the pattern embracing an area where the beam can create a useful image with submicron precision. The method includes: adjusting the beam such that the dose delivered by the beam is sufficiently high to generate a signal produced by the interaction of the beam and the fiducial pattern, the signal being representative of the relative position of the fiducial pattern and the travel, the dose being sufficiently low so that the area of the substrate over which the beam passes remains receptive to subsequent creation, with submicron precision, of a useful image; moving the beam across the substrate; detecting the signal produced by the interaction of the beam with the fiducial pattern; and comparing the detected signal with a predetermined signal to provide a position signal representative of the beam travel with submicron precision.

Energy beam locating

The mask includes an attenuator which passes a fraction of the incident electromagnetic radiation and phase shifts the radiation relative to the radiation passing through open features of the mask by approximately an odd multiple of .pi. radians. This phase shifting of light passing through the attenuator by .pi. radians reduces the edge blurring that results from diffraction effects. The present invention steepens the slope of the intensity profile at the edges of features in x-ray lithographic replication relative to the slope obtained with a conventional x-ray mask. The steeper slope is a highly significant advantage because it permits improved linewidth control.

Growing community of inventors

Lake Peekskill, NY, United States of America

Erik H Anderson