Abstract: Ion beam lithography of particular interest in the fabrication of large-scale integrated circuits of unexpectedly increased throughput results from appropriate choice of (a) resist material and (b) ion species. Resist material, generally negative acting, is characterized by electron beam sensitivity inadequate for ordinary commercial electron beam lithography. The relevant characteristic responsible for inadequate electron beam sensitivity is the very characteristic responsible for enhanced ion sensitivity. Ion species, always of atomic number greater than that of proton, are dictated by the observation that sensitivity unexpectedly increases at a greater rate than predictable on traditional bases.

Abstract: The magnetic anisotropy field in a layer of magnetic material on a substrate is determined by a method involving the application of a magnetic field upon whose release a so-called "sea of bubbles" is observed. The direction of this field typically is at a nonzero angle of elevation relative to the layer.In accordance with the invention, a preferred angle of elevation is determined upon inspection of a functional relationship between angle of elevation and magnetic field strength associated with the observation of a sea of bubbles. Results obtained by the method compared favorably with results obtained based on magnetic resonance techniques and, since the method is also relatively simple, it is particularly suitable for quality control in the manufacture of magnetic bubble devices.

Abstract: Magnetically actuated devices such as, e.g., switches and synchronizers typically comprise a magnetically semihard component having a square B-H hysteresis loop and high remanent induction. Among alloys having such properties are Co-Fe-V, Co-Fe-Nb, and Co-Fe-Ni-Al-Ti alloys which, however, contain undesirably large amounts of cobalt.According to the invention, devices are equipped with a magnetically semihard, high-remanence Fe-Mo-Ni alloy which comprises Mo in a preferred amount in the range of 2-26 weight percent and Ni in a preferred amount in the range of 0.5-15 weight percent.Magnets made from alloys of the invention may be shaped, e.g., by cold drawing, rolling, bending, or flattening and may be used in devices such as, e.g., electrical contact switches, hysteresis motors, and other magnetically actuated devices.Preparation of alloys of the invention may be by a treatment of annealing and aging or deformation and aging.

Abstract: Optical communications networks may be implemented by means of a patterned layer of an optically transparent material on a substrate. Where an optical path terminates, e.g., at an on-off switch, it is desirable to optically terminate a waveguide so as to minimize spurious signals due to reflection.The invention provides for optical termination of a waveguide by essentially complete absorption of light. Absorption is effected in a portion of the waveguide which comprises light absorbing centers such as, e.g., carbon or metal particles, anions, cations, or molecules which absorb light at desired wavelengths. Absorbing centers may be comprised in a central portion of a waveguide or, more conveniently, in a portion adjacent to a central portion.

Abstract: High-resolution patterning of a device surface is effected by a method which involves the use of a multi-layer resist structure. An organic resist layer is on the surface to be patterned, and an inorganic resist layer is on the organic resist layer. A pattern is produced in the inorganic layer by exposure to actinic radiation and, after development of the inorganic layer, the pattern is replicated in the organic layer by additional exposure to actinic radiation. The pattern is then developed in the organic layer so as to leave exposed surface portions to be affected by a fabrication agent.

Abstract: Magnetic devices exemplified by bubble devices depend upon functional magnetic layers initially produced by epitaxy and reduced to effectively thinned surface layers by ion implantation. Implantation is at well-defined energy spectral levels which minimize effect on surface layers and which predominantly affect a "buried layer". As a result, such affected layer acts as a boundary layer of a functional layer which is spaced away from an interface between a substrate and a deposited layer.Commercial significance is primarily concerned with high bit density devices in which effectively thinned regions are less than 3 micrometers in thickness.

Abstract: Domain wall motion in a slab of ferroelectric material gives rise to an electrical signal which may correspond, e.g., to electrode width fluctuations or to a radiation pattern incident on a sensitive layer. A device may have numerous ferroelectric readout tracks, in which case the number of electrical leads can be minimized by a layout in which unidirectional movement of a planar ferroelectric domain wall not only serves to scan a track but also select a track from a large number of tracks. Such device operation is a feature of a device in which a ferroelectric slab is cut, e.g., in the manner of a comb or ladder. Resulting devices may be operated by judicious cycling of voltages at as few as two control electrodes, one defining an access track, and the other being common to the readout tracks.

Abstract: Indium phosphide stoichiometry in III-V semiconductor devices is sensitive to processing conditions during liquid phase epitaxy deposition. Disclosed is a method for determining indium-to-phosphorus ratio in an n-type indium phosphide semiconductor surface layer by monitoring photoluminescence at an absorption band at or near 0.99 electron volt.

Abstract: Permanent magnet materials such as Al-Ni-Co-Fe, Mo-Co-Fe, and Co-Cr-Fe alloys comprise cobalt which has become increasingly expensive. Mn-Al is a cobalt-free magnet alloy which, according to the invention, is used to produce isotropic magnets having a maximum energy product of at least 1 million gauss-oersted. Magnets are produced by rapid quenching from a melt, e.g., by splat cooling, melt extraction, or helium blast cooling, followed by a magnetic aging heat treatment. Magnetic particles such as, e.g., fiber sections are bonded, bundled, or encased to form a magnet having desired shape.

Abstract: To provide for an inexpensive magnet alloy, isotropic and nearly isotropic permanent magnet properties are developed in Fe-Mo-Ni alloys. Manufacture may be by a method which comprises steps of annealing, optional deforming by a limited amount, and aging.Typical magnetic properties of alloys of the invention are a coercive force in the range of 50-500 oersted, a magnetic remanence in the range of 7000-14,000 gauss, and a magnetic squareness ratio of less than 0.9. Alloys of the invention are highly ductile even after plastic deformation, they are readily bonded to aluminum supports (as used, e.g., in the manufacture of twistor memories), and they are readily etched by etchants which leave aluminum unaffected.

Abstract: Magnetically actuated devices such as, e.g., switches and synchronizers typically comprise a magnetically semihard component having a square B--H hysteresis loop and high remanent induction. Among alloys having such properties are Co--Fe--V, Co--Fe--Nb, and Co--Fe--Ni--Al--Ti alloys which, however, contain undesirably large amounts of cobalt.According to the invention, devices are equipped with a magnetically semihard, high-remanence Fe--Mo--Ni alloy which comprises Mo in a preferred amount in the range of 2-26 weight percent and Ni in a preferred amount in the range of 0.5-15 weight percent.Magnets made from alloys of the invention may be shaped, e.g., by cold drawing, rolling, bending, or flattening and may be used in devices such as, e.g., electrical contact switches, hysteresis motors, and other magnetically actuated devices.Preparation of alloys of the invention may be by a treatment of annealing and aging or deformation and aging.

Abstract: Magnetically actuated devices such as, e.g., switches and synchronizers typically comprise a magnetically semihard component having a square B-H hysteresis loop and high remanent induction. Among known alloys having such properties are Co-Fe-V, Co-Fe-Nb, and Co-Fe-Ni-Al-Ti alloys which, however, contain undesirably large amounts of cobalt.According to the invention, devices are equipped with a magnetically semihard, high-remanence Fe-Cr-Mo alloy which comprises Cr in a preferred amount in the range of 6-26 weight percent and Mo in a preferred amount in the range of 1-12 weight percent. Preparation of alloys of the invention may be by a treatment of annealing, deformation, and aging.Magnets made from alloys of the invention may be shaped, e.g., by cold drawing, rolling, bending, or flattening and may be used in devices such as, e.g., electrical contact switches, hysteresis motors, and other magnetically actuated devices.

Abstract: Imaging of 1-, 2-, or 3-dimensional specimens is effected based on nuclear magnetic resonance of a chemical species. A specimen is placed in an essentially constant magnetic field H.sub.o, exposed to an electromagnetic pulse, and exposed to an an additional magnetic field H.sub.1 whose strength is linearly increasing across the specimen. A free induction decay signal is sampled after field H.sub.1 is turned off, and sample values are stored for later processing. These steps are carried out repeatedly for different fields H.sub.1, and stored sample values are Fourier transformed into desired frequency spectra at points in the specimen.

Abstract: In view of rising cobalt costs, low-cobalt alloys such as, e.g., Fe-Cr-Co alloys are finding increasing use in the manufacture of permanent magnets. Desired magnetic energy product of such magnets is typically at least 1 million gauss-oersted.In the interest of maximizing magnetic energy product per unit weight cobalt, low-cobalt Fe-Cr-Co alloys are processed by solidifying a bulk object from a melt, annealing, quenching, and aging by cooling at rates in a range of 0.1 to 2 degrees C. per hour in a magnetic field. Cold working prior to aging may be used to further enhance magnetic energy product.Resulting magnets have optimized maximum magnetic energy product (BH).sub.max per unit weight cobalt comprised in an alloy.

Abstract: In the interest of mechanical strength and hardness, metallic bodies desirably contain dispersed particles whose diameter preferably is in the range of 50-10,000 Angstrom. A disclosed method for producing such metallic bodies calls for preparing a solution of mixed salts of elements, removing the solvent, transforming to metallic form, and compacting under pressure. Strength of a resulting metallic body may be further developed by aging and, optionally, cold deformation prior to aging.Use of the disclosed method is indicated especially to produce bodies comprising immiscible elements. For example, when Mo is dispersed in Cu, high strength and electrical conductivity are realized.

Abstract: Power handling capability and gain of metal-semiconductor field effect devices is adversely affected by a phenomenon variously known as gate-drain avalanche or gate breakdown which occurs at elevated gate-drain voltage. Consequently, it is desirable to design devices so as to maximize gate-drain breakdown voltage V.sub.gd consistent with maximum output power capability.According to the invention, such voltage is maximized by a gate-drain configuration which involves approximate equalization of per-unit-area mobile charge in a portion of the active layer under the gate contact and in an adjoining portion between gate and drain contacts. Equalization of charge may be achieved by appropriate doping or appropriate choice of layer thickness, either alone or in combination. In particular, if dopant concentration per unit volume is essentially equal in the two portions, approximate equalization of conducting channel thickness in the two portions is called for.

Abstract: Single crystals are conveniently produced by directional solidification of a liquid body under a pressurized atmosphere and, preferably, under a liquid encapsulating layer to minimize loss due to volatilization. Such fabrication entails a concern with internal stress in a grown crystal in the interest, e.g., of minimization of breakage of wafers cut from a crystal. According to the invention, minimization of stress is accomplished by means of a post-growth annealing step during which pressure is reduced substantially and, in particular, preferably to a pressure which does not exceed 50 percent of a pressure at which a constituent of the liquid body volatilizes.The method may be applied for producing single crystals of semiconductor materials as may be used as device substrates. In particular, the method is beneficial, e.g., for producing high-quality doped or undoped InP, GaP, and GaAs single crystals.

Abstract: Fabrication of single crystals of III-V semiconductor materials such as, e.g., indium phosphide by pulling from a melt may be hampered by twin formation. It has been discovered that twin formation is prevented by adjusting processing parameters such as, e.g., melt temperature, rotation rate, thermal gradients, and pull rate so as to limit rate of diameter enlargement of a boule. Specifically, diameter enlargement preferably does not exceed 0.3577 times the increase in length of a boule being pulled.

Abstract: Cu-Ni-Sn alloys are disclosed which are particularly suited to undergo shaping by machining such as drilling, and lathing. In addition to Cu, Ni, and Sn, these alloys contain specified small amounts of Te, Se, Pb, or MnS. When articles are formed by machining of alloys having such specified composition, clogging of the machining tool and overheating of workpiece and machining tool are effectively prevented.

Abstract: Copper alloys are disclosed which contain nickel and tin and Fe, Zn, Mn, Zr, Nb, Cr, Al, or Mg in amounts within specified limits. When cold worked and aged according to a critical schedule these alloys develop a predominantly spinodal structure which renders them strong as well as ductile. The disclosed alloys are useful, for example, in the manufacture of components of electrical apparatus such as springs, connectors and relay elements.