Abstract: A plasma etching system includes a grounded reactor chamber having ungrounded chuck and counter electrodes therein. Circuitry is provided so that the potentials applied to the electrodes are about half those normally applied in single ended systems so that stray electrical discharges from the electrodes to the reactor chamber and other parts in the system are minimized.

Abstract: The microbalance includes a mounting having two vertically aligned elongated flexible metal tension members, the upper and lower ends of the tension members being attached to a fixed support. The attachment of one end of each of the tension members to the fixed support is carried out by a resilient tension means. A pivot crossbeam is fixedly attached to the balance beam, and the ends of the pivot beam are fixedly attached respectively to the tension members at points intermediate to the ends. Deflection of the microbalance beam is accommodated by flexure of the metal tension members.

Abstract: A telescope for eliminating on axis coma due to tilt of the secondary mirror in infrared astronomy. The secondary mirror of a reflecting telescope is formed to cause field coma to always be equal and opposite at the optical axis of the telescope to tilt coma regardless of the angle through the secondary mirror is tilted with respect to the optical axis.

Abstract: A semiconductor chip having bond pads formed on a peripheral ledge recessed below the active chip surface. Ultrasonic wire bonds are made with the pads to lie below the active chip surface.

Abstract: An R.F. impedance match control system. The reflection coefficient of the system is compared to a threshold to determine a mismatch condition which is corrected by selectively changing in incremental steps the turns ratio of an autotransformer provided at the input to the load until the mismatch condition is corrected. Timing means are provided to delay each mismatch correction until initial transient conditions are stabilized and to shut off R.F. power during each turns ratio change.

Abstract: This invention is directed to a new and improved system for determining optical aberrations, such as for example alignment, focus, tilt, astigmatism or coma of a telescope optical system, wherein the telescope optical system is arranged for imaging a random scene and includes a plurality of subapertures, said system comprising a grating disposed at the focal plane of the telescope optical system, an apodizing mask disposed adjacent the grating, said mask having transparent and opaque portions, an array of light detectors, a field lens disposed adjacent the grating for causing the subapertures to be imaged on the array of detectors, apparatus for effecting relative movement between the grating and the other elements, phase detector electronics for receiving the output from the detectors and outputting individual detector signals, and a processor responsive to the detector signals for determining the difference in phase between the individual detector signals and a reference phase, whereby a measure of the aber

Abstract: A relatively small amount of high frequency RF power is mixed with a predominantly low frequency RF power to provide an improved etch rate uniformity of a semiconductor wafer in a low frequency plasma etching system.

Abstract: Pressurized gas is applied between a wafer and electrode in a plasma etching system. Gas between the wafer and electrode provides cooling of the wafer. A control arrangement maintains the gas at a predetermined pressure.

Abstract: An electrode includes a plurality of nested concentric rings forming plenum chambers. Process gas is fed into the plenum chambers through capillary tubes. The gas is then delivered through slits between the rings into a plasma etching reactor.

Abstract: Disclosed is a method and apparatus for optically testing cylindrical surfaces in which a collimated beam of monochromatic light is directed to a variably spaced linear grating which produces two first order cylindrical wavefronts: one, a converging beam in the blaze direction and, two, a diverging beam in an antiblaze direction. The blaze direction beam converges into a line focus. Either a concave or convex cylindrical mirror may be positioned with its axis at that line focus in the appropriate part of the beam to return the rays along their original path to the grating where they interfere with the antiblaze wavefront. By locating a screen of any suitable type in the path of the antiblaze beam, a fringe pattern representing the figure quality of the cylindrical surface under test is formed on the screen. Both concave and convex, coated and uncoated, cylindrical surfaces can be tested by this method and apparatus.

Abstract: The flame in a flame atomic absorption spectrophotometer is shut down while using nitrous oxide as the oxidant, without shifting to a different oxidant such as air, by flooding the burner with a substantial excess of nitrous oxide to blow out the flame.

Abstract: This invention relates to unequal path interferometers which are adapted, among other possible uses, for use in detecting coherent radiation as from a laser in a packet of radiation including incoherent background radiation, which includes an unequal optical path length interferometer of the type in which portions of the radiation impinging on the interferometric component are caused to be recombined after travelling two different optical paths; the optical paths differing in length by an amount substantially greater than the coherence length of the non-coherent radiation but substantially less than the coherence length of the coherent radiation; the unequal optical path length interferometric component including a crystalline cell having anisotropic properties; circuitry for applying an ultrasonic sound wave to the crystalline cell to vary the effective index of refraction of the crystalline cell in a preselected systematic manner; a detector for detecting the intensity of the recombined portions and produci

Abstract: The present invention is directed to an improved unequal path interferometer which is a particularly adapted, among many other possible uses, for detecting coherent radiation in the presence of non-coherent ambient radiation, which comprises an unequal optical path length interferometer of the type in which portions of the radiation impinging on the interferometric component are caused to be recombined after travelling two different optical paths; the optical paths differing in length by an amount substantially greater than the coherence length of the non-coherent radiation but substantially less than the coherence length of the coherent radiation; the unequal optical path length interferometric component comprising a liquid crystal cell having dielectric anisotropic properties; elements for applying a time varying electric field vector to the liquid crystal cell to vary the effective index of refraction of the liquid crystal cell in a preselected systematic manner; and elements for detecting the intensity of

Abstract: The present invention is directed to improvements in apparatus for analyzing coherent radiation in the presence of non-coherent ambient radiation subject to atmospheric scintillation effects, using unequal path interferometer apparatus and detector apparatus, said improvements comprising a closely packed bundle of fiber optic elements having an input face disposed adjacent the interferometer apparatus for receiving incident radiation passing therethrough, each of the elements being of a substantially smaller diameter than the atmospheric scintillation spatial structure; the said bundle of fiber optic elements having a medial portion wherein the elements are sorted or arranged into a plurality of subbundles; and said detector apparatus having a plurality of detector elements, each detector element being mounted adjacent one of the subbundles for being illuminated thereby.

Abstract: A non-imaging detector for directly measuring the angle of incidence of irradiation in one plane from an illuminating source. The detector includes a slit mask that transmits narrow lines of irradiation across an array of detectors closely underlying the slit mask. The detectors are configured to generate photocurrents whose ratio exponentially increase as the irradiation lines through the slits move along the array in response to changes in angle of incidence. The detectors are configured according to an exponential formula so that adjacent rows of detectors produce photocurrents so that the photocurrent log difference from adjacent rows will result in a signal directly proportional to incidence angle when subtracted by associated circuitry.

Abstract: An apparatus and method are disclosed to optimize resolution of unknown samples by liquid chromatography. A plurality of resolution experiments are performed where the solvents in the liquid chromatograph column are changed from one experiment to the next. The chromatogram for each experiment is analyzed to measure its peak resolution. A measure of peak resolution is displayed for each chromatograph thereby allowing the operator to select easily the chromatograms with the required peak resolution and determine the solvent conditions required to produce that resolution.

Abstract: The present invention is directed to a combination of elements for use in an alignment system for a scanning mask aligner, which include a viewing system having an optical grid, apparatus for moving the mask and wafer alignment patterns across the optical grid, each pattern having front edge portions displaced with respect to rear edge portions in the direction of scanning so that only light corresponding to a plurality of said front edge portions is transmitted through the grid at one time and only light corresponding to a plurality of the rear edge portions being transmitted through the grid at a second later period of time, the grid corresponding to the directions and spacing of the pattern so that light transmitted through the grid is strongly modulated, and circuitry responsive to the transmitted light operative to output alignment signal errors.

Abstract: The present invention is directed to a new and improved combination operative with an image acquisition system wherein a field-of-view is panned over a fixed image format; said combination comprising a sensor, an optical system for imaging the field-of-view at the sensor, said sensor including four linear arrays disposed in quadrilateral configuration, two of said arrays being applied to each half of a beam splitter cube; row and column buffers which are continuously updated every integration period, and a controller which strobes the buffers into a frame store memory after one resolution element width or pixel has been traversed.

Abstract: This invention is related to method and devices for applying and holding a wafer chuck assembly against an X, Y, .theta. alignment plate, said system including latching a wafer chuck assembly with a chuck handling device while inserting alignment pins carried by the device into corresponding V-like grooves in the chuck assembly to form a rigid unit, mounting the unit on pins extending from the X, Y, .theta. alignment plate, releasing the latching to allow the chuck assembly to fall downwardly a short distance until it rests on the X, Y, .theta. pins, and extending two pistons from the chuck handling device to engage the wafer chuck assembly to urge it snugly against the X, Y, .theta. alignment plate until the chuck assembly and alignment plate are locked together by vacuum means.

Abstract: An achromatic imaging system employs a diffractive hologram as the primary element. A conventional achromatic optical element, comprising either a refractive lens or mirror, is positioned between the primary element and a second holographic optical element. The holographic and conventional elements combine to form an imaging system characterized by high resolution and light weight.