Abstract: Embodiments of the present disclosure are directed to an electron beam imaging/inspection apparatus having an electron source device to direct flood electrons on a sample immediately before image acquisition or inspection. The apparatus comprises a first device configured to charge a sample in a first mode, wherein the first device includes an electron source configured to provide a flood beam of charged particles to a first area of the sample. The apparatus also comprises a second device configured to generate a primary beam of electrons and characterize an interaction between the primary beam and a second area of the sample within the first area in a second mode. The apparatus is configured to switch from the first mode to the second mode less than 1 second.

Abstract: An SEM wherein the entire imaging apparatus of the SEM is supported on air bearings. A multi-stage differentially pumped vacuum seal area provides a localized vacuum zone for wafer examination. A wafer leveling mechanism insures that the top surface of the wafer being examined is placed and maintained in a position level with the surface upon which the air bearing supported SEM rests. The SEM can move on its air bearings such that any portion of the wafer can be examined. A voltage-isolating passageway for providing high voltage isolation between a component maintained at high DC voltage and a component maintained at a substantially lower voltage is described. The voltage-isolating passageway incorporates a transverse magnetic field across its passageway. The voltage-isolating passageway includes at least two magnets that are positioned along opposite and exterior surfaces of the passageway. A semi-conductive coating can be applied to the interior passageway surface.

Abstract: One embodiment disclosed relates to a scanning electron beam apparatus including an objective lens, scan deflectors, de-scan deflectors, an energy-filter drift tube, and a segmented detector. The objective lens may be an immersion lens configured with a high extraction field so as to preserve azimuthal angle discrimination of the electrons scattered from the specimen surface. The de-scan deflectors may be used to compensate for the scanning of the incident electron beam. The energy-filter drift tube is configured to align the scattered electrons according to polar angles of trajectory from the specimen surface.

Abstract: An embodiment of the present invention comprises a SEM wherein the entire imaging apparatus of the SEM is supported on air bearings. A multi-stage differentially pumped vacuum seal area provides a localized vacuum zone for wafer examination. A wafer leveling mechanism insures that the top surface of the wafer being examined is place and maintained in a position level with the surface upon which the air bearing supported SEM rests. In use, wafers being examined are loaded into the wafer leveling mechanism, which places and then holds their top surface flush with an examination table. The SEM is then moved on its air bearings and placed in appropriate position over the wafer. Any portion of the wafer can be examined simply by moving the SEM column in the appropriate direction.

Abstract: Methods are provided for depositing insulator material at a pre-defined area of an integrated circuit (IC) by: placing an IC in a vacuum chamber; applying to a localized surface region of the integrated circuit at which insulator material is to be deposited a first gas containing molecules of a dissociable compound comprising atoms of silicon and oxygen and a second gas containing molecules of a compound which reacts with metal ions; generating a focused ion beam having metal ions of sufficient energy to dissociate molecules of the first gas; and directing the focused ion beam at the localized surface region to dissociate at least some of the molecules of the first gas and to thereby deposit on at least a portion of the localized surface region a material containing atoms of silicon and oxygen. The dissociable compound comprises atoms of carbon and hydrogen, such as di-t-butoxydiacetoxy-silane. The compound which reacts with metal ions may be carbon tetrabromide or ammonium carbonate.

Abstract: Preferential etching during FIB milling can result in a rough, pitted surface and make IC probing/repair operations difficult. Preferential etching is compensated by acquiring a contrast image of the partially-milled sample, preparing mask image data from the contrast image, and controlling further FIB milling using the mask image data. For example, a window is to be milled in a top-layer power plane of an IC to expose a hidden layer. The window is partially milled. A FIB image is acquired and thresholded to produce mask image data. The mask image data distinguish areas where the power plane has been milled through from those where it has not been milled through. Milling is resumed using the mask image data to control effective FIB milling current. The mask image data are updated periodically as the window is milled.

Abstract: Focused ion bean (FIB) milling through a power plane of a device to expose or cut a hidden, lower-layer conductor requires accurate positioning relative to the hidden conductor of a box defining boundaries of the FIB operation. This can in general be done by aligning surface information (topology or voltage contrast) visible in a FIB or scanning electron microscope (SEM) image with an overlay image generated from stored data describing the device. The location of the hidden conductor relative to the visible surface information is determined from the stored data. Advanced integrated circuits often do not provide enough unique surface information near the FIB operation area to align the images with sufficient accuracy.

Abstract: A surface is probed with a pulsed electron beam and secondary electrons are detected to produce a detector signal. First portions of the detector signal are substantially dependent on the voltage of the surface being probed, while second portions of the detector signal are substantially independent of the voltage of the surface being probed. In general, the first and second portions of the detector signal include unwanted noise caused by low-level sampling due to beam leakage and/or by scintillator afterglow in the secondary-electron detector. The detector signal is sampled during the first signal portions and is sampled during the second signal portions. The sampled first signal portions are combined with the complement of the sampled second signal portions to produce a measured voltage signal representing voltage of the conductor. In a preferred sampling scheme, alternate electron-beam sampling pulses are held-off.

Abstract: Apparatus is provided which includes a FIB column having a vacuum chamber for receiving an IC, means for applying a FIB to the IC, means for detecting secondary charged particles emitted as the FIB is applied to the IC, and means for electrically stimulating the IC as the FIB is applied to the IC. The apparatus may be used, for example, (1) to locate a conductor buried under dielectric material within the IC, (2) for determining milling end-point when using the FIB to expose a buried conductor of the IC, and (3) to verify the repair of an IC step-by-step as the repair is made.