Abstract: A non-dispersive electrostatic energy analyzer for electrons and other charged particles having a generally coaxial structure of a sequentially arranged sections of an electrostatic lens to focus the beam through an iris and preferably including an ellipsoidally shaped input grid for collimating a wide acceptance beam from a charged-particle source, an electrostatic high-pass filter including a planar exit grid, and an electrostatic low-pass filter. The low-pass filter is configured to reflect low-energy particles back towards a charged particle detector located within the low-pass filter. Each section comprises multiple tubular or conical electrodes arranged about the central axis. The voltages on the lens are scanned to place a selected energy band of the accepted beam at a selected energy at the iris. Voltages on the high-pass and low-pass filters remain substantially fixed during the scan.

Abstract: An electron energy analyzer including a curved electrostatic low-pass reflector and a high-pass electrostatic transmissive filter. The reflector comprises a curved grid, preferably ellipsoidal, and an absorber electrode placed in back of the curved grid with respect to the electron source and biased negatively to the curved grid to act as a reflective low-pass filter and a collimating optics for the reflected beam. The transmissive filter includes first and second flat grids extending across the collimated reflected beam. The second grid on the side of the first grid opposite the curved grid is biased negatively to the first grid and the absorber electrode. A field free region is created by applying the same bias to the curved grid, the first grid, and chamber sidewall sleeve. An electron detector detects all electrons passed by the second grid in an energy band in the overlap of the high-pass and low-pass bands.

Abstract: A vacuum window transmitting keV electrons and usable for high-pressure electron analysis such as XPS and AES in which the sample is positioned outside the UHV analyzer chamber, possibly in a controlled gas environment, relatively close to the window. The window includes a grid formed from a support layer and a thin window layer supported between the ribs and having a thickness preferably of 2 to 3 nm. The window and support layers may be deposited on a silicon wafer and the support layer is lithographically defined into the grid. The wafer is backside etched to expose the back of the grid and its supported window layer. Such a window enables compact and easily used electron analyzers and further allows control of the gas environment at the sample surface during analysis.

Abstract: A method and apparatus for measuring the thickness of a thin coating, having a thickness on the order of 1 to 10 nm, of one material formed over a substrate of another material of significantly different atomic number, for example, a carbon coating on a ferromagnetic substrate. A primary radiation source, for example, of electrons or X-ray, creates low-energy secondary electrons in the substrate. The intensity of inelastically scattered electrons generally increases with film thickness. The secondary electron spectrum measured for a test sample is compared with the spectra for a plurality of similar reference samples of the same set of compositions, and a test thickness is thereby determined. The method may be practice on conventional electron spectrometers with the addition of some programmed analysis. Various techniques are available for extracting the data and comparing the test and reference data.

Abstract: Apparatus for holding and aligning a sample to be examined by a scanning electron microscope or the like includes an alignment device having base structure installable in the scanning electron microscope in a predetermined orientation. The alignment device also includes a holder for the sample which is mounted to the base structure for rotative movement about a rotation axis relative to the base structure. An adjuster is mounted on the base structure and can be manipulated to rotate the sample holder about the rotation axis. This alignment device is installed in a base holder and a video camera captures an image of the sample held by the sample holder. The image is displayed on a video monitor and the adjuster is then manipulated to rotatively align the sample to a desired orientation. The alignment device, including the sample, may then be removed from the base holder and installed in the scanning electron microscope with the sample being properly aligned.

Abstract: A method and apparatus associated with an atomic force microscope (AFM) to more accurately measure the height of a microscopic feature in a substrate, particularly one having a sloping face. The probe tip is sequentially positioned at a number of vertical positions approaching the surface being probed. At each vertical position, a vertical force encountered by the probe tip is measured, and the measured force is stored in a memory together with its corresponding vertical position. When the measured force exceeds a threshold force, the downward movement is stopped, and the accumulated force and position data are analyzed. A controller fits the data to two curves, for example, two linear relationships in force vs. height. One curve is associated with the lower forces away from the surface, the other curve with the higher forces after initial engagement with the surface. The intersection of the two curves gives the height of the feature in the surface.

Abstract: A probe tip locator for use in determining the x-axis location and y-axis location of a probe tip of a microscope relative to the locator, the locator comprising a plurality of first reference lines parallel in a first direction, each of the first reference lines representing a predetermined x-axis location of the probe tip; a plurality of sets of parallel encoded bit fields, each one of the sets corresponding to one of the first reference lines; and a plurality of second reference lines parallel in a second direction, each one of the second reference lines intersecting at least one of the first reference lines at an acute angle, such that a scan of a portion of the locator is used to determine the x-axis location and y-axis location of the probe tip relative to the probe tip locator by movement of the probe tip relative to the probe tip locator.

Abstract: A scanning probe microscope equipped with a mechanism for exchanging a probe balance beam from the scan head, wherein the probe balance beam is of the type which is magnetically constrained on the scan head. A magnet having a magnetic field strength greater than that of the scan head magnet is utilized to overcome the attractive force exerted on the balance beam by the scan head magnet and transfer the balance beam from the scan head to a plate in a holding station on the sample table of the microscope. Completely automatic operation is achieved without operator handling of the balance beam.

Abstract: An electron energy analyzer uses identical sectors, typically though not necessarily ninety degree segments of a toroid, disposed in complementary relationship with an aperture therebetween to provide a mapping of the image at the entrance plane to the exit plane while permitting the desired energy analysis to be performed.

Abstract: A precision magnetic manipulator for use in positioning targets, and the like, within a vacuum chamber, employs separate mechanisms for linear and rotational motion and makes them substantially independent. Ball or roller style bearings support a square, linear shaft within a housing, at least one set of bearings being at the point at which the shaft exits the housing, and another set being within the housing along the route of travel of the linear shaft, so that the shaft is fully being supported over the entire travel length. A magnet carriage supporting high-strength magnets, one system being optimized for rotational motion and the other being optimized for linear motion, couples to magnet followers within the housing, thereby providing rotational motion and linear motion which can be used in combination or separately, giving great freedom of movement within the vacuum chamber.

Abstract: In an electron spectrometer, electrons emanating from a source are collected and focused to a collimated stream by an electrostatic lens free of spherical aberration. The lens includes a pair of axially spaced concave grids approximating sections of concentric ellipsoids having a common focii and coaxial semi-major axes. The collimated electron stream is inducted into an electric radial cylindrical analyzer for focusing the electrons into radially dispersed lines on a position-sensitive detector with the radial dispersion being a function of their energies. The cylindrical analyzer section subtends an angle of approximately 63.5.degree.. The grid openings in the grids of the electrostatic collimating lens are elongated in a direction transverse to the stream of the electrons passing therethrough and parallel to the radial electric field lines at the entrance to the electric analyzer to reduce the dispersive effect of the grids.

Abstract: An electron spectroscopy system is disclosed which is specially suited for chemical analysis of electrically isolated specimens. X-rays or other ionizing radiation is focused to a relatively small spot on the surface of the electrically isolated sample to be analyzed. An electron energy analyzer has its input optics focused such that the input field of view of the electron energy analyzer is coincident with the beam spot produced by the focused beam of ionizing radiation on the specimen so as to capture secondary photoelectrons emitted from the surface of the sample under analysis. The energies of the secondary photoelectrons are analyzed to obtain a spectrum of the constituents of the surface of the sample under analysis. A flood beam of relatively low energy electrons is directed onto the surface of the sample for neutralizing the positive surface charge in the region of the beam spot.

Abstract: A spectrophotometer optical section is presented which employs a fine positioning beam director which corrects for any deflections of the output beam path and accurately positions the optical beam on the detector slit of the spectrograph. The detector slit is chosen to have a size slightly smaller than the size of the optical beam at the detector slit to have high slit throughput without introducing spurious absorption. The sample cells need not be rigidly mounted thereby enabling use of a sample cell and cell holder which allows quick, easy interchange of cells.

Abstract: A beam directing device is provided which employs one or more mirrors mounted on a single rotatable shaft. The orientation of the shaft controls the rotational orientation of these directing mirror(s) to direct the beam toward any of a number of sample or reference cells. Behind each cell is a cube corner which reflects the beam back to the directing mirror(s) for reflection toward the detector. In one embodiment, a shaft encoded senses the orientation of the shaft, the encoder output being servoed against a position signal to coarsely rotate the shaft in order to direct the beam to a sample cell and thence to a spectrograph slit. A pair of slit diodes detect the beam overlap on each side of the slit and their output is used to accurately position the beam on the slit to within one second of arc and correct for deviations in beam direction.

Abstract: A device is provided for measuring the concentration of oxygen in a sample utilizing the differential absorption by oxygen (O.sub.2) of two closely spaced ultraviolet (UV) radiation lines. The two UV lines are preferably isotope-shifted Hg lines in the vicinity of the Hg atomic transistion line at 1849.5A.