Abstract:
An excitation device (51) that generates a strong magnetic field nearly perpendicular to the surface of a specimen is arranged in an apparatus for observation using charged particle beams which irradiates the specimen with charged particle beams and detects the generated secondary electrons to observe the surface of the specimen. The secondary electrons emitted from the bottom or side surface of a recess such as a through hole formed in the surface of the specimen (8) are, then, emitted out of the through hole owing to the interaction with the strong magnetic field. A focusing lens (50) is so arranged that a point of focusing of charged particles exists between the focusing lens (50) and the specimen (8), the charged particles being formed when the charged particles of the same intensity as that of the irradiating charged particles are supposed to be emitted from the specimen surface, thereby to focus the charged particle (46) at a position of the point of focusing. Even when the specimen (8) is subjected to the strong magnetic field, therefore, the charged particles (46) can be focused on the upper surface of the specimen. Therefore, a well-defined secondary electron image of the specimen surface can be obtained under the applied strong magnetic field, and the secondary electron image of the bottom or the side of the through hole can be observed.
Abstract:
A morphological operation is applied to an SEM image to obtain a idealized image, and the idealized image is used to detect a defect in a subject of the SEM image. The defect is detected by subtraction of the idealized image from the original image. Morphological operations are used also to entrance the visibility of defects or to check for irregularities in patterns. Other described methods comprise: growing a flow from seed points in the image, in order to define maps in which particles can be identified; checking for separation of objects in the image by growing flows from seed points located on the objects; segmenting the image into supposed identical objects and applying statistical methods to identify the defective ones.
Abstract:
A system and method for multi detector (14, 40) detection of electrons, the method includes the steps of directing a primary electron beam, through a column, to interact with an inspected object (wafer), directing, by introducing a substantial electrostatic field, electrons reflected or scattered from the inspected objects (wafer) towards multiple interior detectors (14, 40), whereas at least some of the directed electrons are reflected or scattered at small angle in relation to the inspected object (wafer); and receiving detection signals from at least one interior detector.
Abstract:
A method for process monitoring includes receiving a sample having a first layer that is at least partially conductive and a second layer formed over the first layer, following production of contact openings in the second layer by an etch process, the contact openings including a plurality of test openings having different, respective transverse dimensions. A beam of charged particles is directed to irradiate the test openings. In response to the beam, at least one of a specimen current flowing through the first layer and a total yield of electrons emitted from a surface of the sample is measured, thus producing an etch indicator signal. The etch indicator signal is analyzed as a function of the transverse dimensions of the test openings so as to assess a characteristic of the etch process.
Abstract:
A charged particle beam device is described. The charged particle beam device includes a charged particle beam source (12) for emitting a charged particle beam, and a switchable multi-aperture (26) for generating two or more beam bundles (21a, 21b) from the charged particle beam, wherein the switchable multi-aperture includes: two or more aperture openings, wherein each of the two or more aperture openings is provided for generating a corresponding beam bundle of the two or more beam bundles; a beam blanker arrangement (226) configured for individually blanking the two or more beam bundles; and a stopping aperture (227) for blocking beam bundles, which are blanked off by the beam blanker arrangement. The device further includes a control unit electrically connected to the beam blanker arrangement and configured to control the individual blanking of the two or more beam bundles for switching of the switchable multi-aperture and an objective lens (18) configured for focusing the two or more beam bundles on a specimen (19) or wafer, wherein the two or more beam bundles are tilted with respect to the specimen or wafer depending on the position of each of the two or more beam bundles relative to an optical axis defined by the objective lens, and wherein the objective lens is configured for focusing the charged particle beam source, a virtual source provided by the charged particle beam source or a crossover.