Abstract: A method and apparatus for generating an image of a specimen with a scanning electron microscope (SEM) is disclosed. The SEM (200) has a source unit (202 through 220) for directing an electron beam (203) substantially towards a portion of the specimen (222), a detector (224) for detecting particles (205) that are emitted from the specimen (222), and an image generator (234 through 242) for generating the image of the specimen (222) from the emitted particles (205). The image features are controlled by conditions under which the image is generated. The specimen is scanned under a first set of conditions (252) to generate a first image during a first image phase (302, 402). The specimen is then scanned under a second set conditions (254) during a setup phase (304, 404). The second set of conditions is selected to control charge on the specimen. The specimen is then scanned under the first set of conditions (252) to generate a second image during a second image phase (306, 406).

Abstract: A system and method for controlling electron exposure on image specimens by adjusting a raster scan area in-between scan frame cycles. A small, zoomed-in, scan area and the surrounding area are flooded with positive charge for a number of frame cycles between scan frames to reduce the voltage differential between the scan area and surrounding area, thereby reducing the positive charge buildup which tends to obscure small features in scanned images. The peak current into a pixel element on the specimen is reduced by scanning the beam with a line period that is very short compared to regular video. Frames of image data may further be acquired non-sequentially, in arbitrarily programmable patterns. Alternatively, an inert gas can be injected into the scanning electron microscope at the point where the electron beam impinges the specimen to neutralize a charge build-up on the specimen by the ionization of the inert gas by the electron beam.

Abstract: A method and apparatus for generating an image of a specimen with a scanning electron microscope (SEM) is disclosed. The SEM has a source unit for directing an electron beam substantially towards a portion of the specimen, a detector for detecting particles that are emitted from the specimen, and an image generator for generating the image of the specimen from the emitted particles. The image features are controlled by conditions under which the image is generated. The specimen is scanned under a first set of conditions to generate a first image during a first image phase. The specimen is then scanned under a second set of conditions during a setup phase. The second set of conditions are selected to control charge on the specimen. The specimen is then scanned under the first set of conditions to generate a second image during a second image phase. The features of the second image are controlled by the first and second sets of conditions.

Abstract: A system and method for controlling electron exposure on image specimens by adjusting a raster scan area in-between scan frame cycles. A small, zoomed-in, scan area and the surrounding area are flooded with positive charge for a number of frame cycles between scan frames to reduce the voltage differential between the scan area and surrounding area, thereby reducing the positive charge buildup which tends to obscure small features in scanned images. The peak current into a pixel element on the specimen is reduced by scanning the beam with a line period that is very short compared to regular video. Frames of image data may further be acquired non-sequentially, in arbitrarily programmable patterns. Alternatively, an inert gas can be injected into the scanning electron microscope at the point where the electron beam impinges the specimen to neutralize a charge build-up on the specimen by the ionization of the inert gas by the electron beam.

Abstract: The present invention provides methods and apparatus for rapid compression of images composed of pixels into high-resolutions, compressed icon images, and for dynamic fault imaging of operating faults in integrated circuit devices employing such methods. Displaying a plurality of such icons juxtaposed on a screen permits ready tracing of a fault in an IC device under test, even by persons having little knowledge of the functionality of the devices.In accordance with the invention, an image made up of n.times.n pixels may be compressed into an icon of p.times.p pixels, where n.dbd.P.multidot.q and q is an integer, by dividing the image into p tiles of q.times.q pixels, selecting q pixels from each tile, where each of said selected q pixels is representative of predetermined directional orientations within the tile, and calculating the mean value of the selected q pixels, to produce a single pixel representative of the tile. The pixels representative of said tiles thus form an icon of p.times.p pixels.

Abstract: Methods and apparatus are disclosed for rapid and interactive "warping" of a first image made up of pixels to form a resulting image made up of pixels which are aligned, pixel-for-pixel, with a second image made up of pixels. The images may be stroboscopic voltage contrast images representing operating states of two integrated circuit devices--a failing device and a fully functional device. The aligned images permit an engineer who may have little knowledge of the device to diagnose dynamic failures of the failing device by comparing the aligned images to produce an image showing the differences.