Abstract: A method of plasma etching silica at a faster rate than silicon involves using a gaseous mixture containing an unsaturated halocarbon and a saturated halocarbon. The preferred halocarbon contains fluorine. A preferred embodiment is a gaseous mixture containing C.sub.3 F.sub.6 and C.sub.2 F.sub.6.

Abstract: An optical data storage system that utilizes the frequency dimension to increase the storage capacity. The storage system has a storage material which contains a guest material such as cinnoline, which is dissolved in a host material such as naphthalene. This storage material system exhibits an inhomogeneous absorption line broadening and undergoes a photochemical reaction upon exposure to light.

Abstract: A method for detecting the wall state of a soft bubble based upon the collapse characteristics of the bubble domain on a layer of bubble domain supporting material is described. The method includes the step of exchange coupling a magnetic layer, for example, an ion-implanted layer, to the bubble supporting layer. An in-plane field is applied to the bubble supporting layer when Bloch lines are present in the bubble domains. The bias field and the pulse field are set at a level to form a range of pulse widths which are suitable for the discrimination of soft bubble domains having different wall states. A pulse is then applied for a time sufficient to collapse only the S=1 bubble and not the S=0 bubble. Thereby this method distinguishes S=0 bubbles having one pair of winding Bloch lines from S=1 bubbles having one pair of unwinding Bloch lines. This method also distinguishes S=1 bubbles having a clockwise chirality from S=1 bubbles having a counterclockwise chirality.

Abstract: An improved photoconductor for GaAs laser addressed devices sensitive to illumination at about 1.5 eV is an amorphous material containing silicon, hydrogen and a material taken from the group consisting of Ge, Sn and Pb. A preferred embodiment of this invention is amorphous Si.sub.x Ge.sub.1-x H.sub.y where x equals 0.78 to 0.93 and y equals 14-20 atomic percent.

Abstract: A wafer indexing and mapping system is useful for precisely locating artifacts, defects, and fabricated structural components on a wafer. A permanent micrometer grid pattern is applied to the backside of the wafer, for example, a transparent bubble wafer. The grid pattern forms an array of uniform size cells, for example, 40 unit cells wide by 40 unit cells long. Each unit cell is divided into smaller units on each side. Each cell contains a coding or indexing system to identify the row and column of the cell in the grid pattern. The grid pattern contains orientation bars which identify orientation with respect to particular wafer reference lines. The simultaneous viewing of the wafer and the grid pattern permits an accurate permanent mapping of the artifacts, defects, and fabricated structural components on the wafer, as well as on the individual small chips formed by dicing the wafer.

Abstract: An electro-lithography method suitable for forming a high resolution pattern in an electron sensitive resist material is disclosed. This technology permits the inexpensive high resolution reproduction of masks for use in integrated circuits and magnetic bubbles. The method involves the application of a pulsed, electric field to two parallel electrodes having an electron beam resist layer positioned on one of the electrodes and a mask positioned between the second electrode and the resist layer. The mask forms a gap having a thickness of 10.sup.-4 m to 10.sup.-5 m with the resist layer.

Abstract: A method and apparatus for providing an improved hot filament, arc type ion source is disclosed. The arc type ion source utilizes a filament having a carburized surface layer and/or means to provide a hydrocarbon gas containing atmosphere about said filament. The method includes providing an atmosphere containing a hydrocarbon gas about said filament so that the filament can be continuously carburized as part of the ion source.

Abstract: A non-destructive readout scheme suitable for use with a holographic storage system having data stored in three spatial dimensions and one frequency dimension is described. The readout scheme and the holographic storage system use a preferred storage material which undergoes a reversible photochromic reaction involving two inhomogeneously broadened absorption bands. Information is written into the storage system by exposing the material to a holographic interference pattern of light at a frequency within either one of the two absorption bands. The non-destructive readout scheme involves reconstructing the original information by sensing the change in the index of refraction at a frequency just outside of and near either one of the two absorption bands. The readout scheme also includes sensing refractive index changes near one or more narrow absorption lines within either absorption band.

Abstract: An optical data storage system and method that utilizes the frequency dimension to increase the storage capacity significantly. The system includes a storage material, for example, in the form of a block, adapted to undergo a photo induced reaction upon exposure to light and which exhibits inhomogeneous absorption line broadening. Data bits are stored by selective photo induced reactions induced by a narrow band laser at specific frequencies within the broad inhomogeneous line. The lifetime of these photo induced data bits is of the order of years so as to provide a non-volatile storage system. In a preferred embodiment, a material is selected so that the photo induced reaction can be made reversible thereby permitting, when desired, the erasing of the data bits.

Abstract: Ferromagnetic alloys containing palladium suitable for use in magnetic devices and having improved resistance to corrosion contain from about 20 to 65 atomic percent palladium, up to 80 atomic percent iron and 0 to 55 atomic percent nickel. Magnetic films made of these alloys which contain 20 to 65 atomic percent palladium exhibit a magnetization, 4.pi.M, and a corrosion resistance equal to or better than Permalloy.

Abstract: A device and method for obtaining high resolution of electron energy in an electron beam is described. The device has a resonance chamber containing a gas which exhibits a narrow scattering resonance at a specific electron energy value. The device utilizes the narrow resonance property of the gas to filter the electron energy spectrum at that energy value. A preferred embodiment is a spectrometer having an electron accelerator, an electromagnetic filter, a resonance chamber containing helium, and a trapped electron detector device. The electrons in the beam are accelerated and the beam is passed through an electromagnetic filter centered at approximately 20.614 eV. The filtered beam passes into a resonance chamber where the electrons have inelastic collisions with the helium atoms to produce the He2.sup.1 S excited state. The He2.sup.1 S scattering resonance has a narrow width of less than 0.001 eV at its energy threshold of 20.614 eV and serves as a filter.

Abstract: This single level masking process includes the use of two layers of a positive photoresist. A pattern is formed in the first layer of photoresist. This photoresist pattern is heated and polymerized to a degree which permits it to be resistant to attack when covered with a second layer of the same positive photoresist, that is, the first photoresist pattern will maintain its integrity. After the heat treatment, the first layer pattern is substantially insensitive to actinic radiation and is easily stripped with conventional solvents. A pattern is formed in a second layer of photoresist that is different from the pattern formed in the first layer. After a first metal is deposited on portions of the substrates exposed in the second layer pattern, the second layer pattern is removed. A second metal is deposited on the portions of the substrate exposed in the first layer pattern and then that pattern is removed.

Abstract: A process for slicing boules of a single crystal material such as gadolinium gallium garnet (GGG) into wafers is described. The boule is prepared, by grinding preferably, so that the longitudinal boule axis corresponds to the crystallographic orientation axis of the boule. The boule is then mounted in a fixture and aligned so that the common longitudinal axis and crystallographic orientation axis is perpendicular to the saw blade. The boule is then rotated while maintaining the orientation of the combined common axis and engaged against an inner diameter rotating saw blade for a time sufficient for the blade to slice through the boule and form a wafer. The wafers obtained by this slicing process may be directly polished without the conventional lapping step to form a wafer having a surface that is substantially flat, parallel and defect free.

Abstract: Two parallel conductors are positioned on top of a magnetic layer where bubble domains are to be coded. The two parallel conductors are positioned to form a gap therebetween of a particular size. An external in-plane magnetic field is applied to the magnetic layer. The size of the gap is selected such that when current is simultaneously applied in both conductors, a local in-plane field will be formed in the gap which is sufficient for coding bubble wall states and a vertical field will be formed in the gap sufficient to retain a bubble in the gap during the application of current to the conductors. The application of current in the one direction in the conductors codes a bubble with one pair (S = 0) of Bloch lines and the application of current in the opposite direction codes a bubble with no Bloch lines (S = 1).

Abstract: A device adapted for biasing bubble domains in a low externally applied magnetic bias field. This device is suitable for use when isolated bubbles or a column of bubbles are translated to or from a bubble lattice. The device has a pair of parallel channels, each containing a stripe domain therein. Positioned between the pair of channels is a channel for the translation of isolated bubbles. Positioned in juxtaposition with the bubble containing channel and the pair of stripe containing channels are a pair of parallel conductors. The passage of current through one conductor in one direction and a current through the other conductor in the opposite direction together with the presence of the stripe domains in the two channels provide a biasing field around the channel containing the bubbles which permits the isolated bubble operating margin to overlap the lattice operating margin.

Abstract: Field access system for use in propagation of bubbles is disclosed. The field access system combines discrete drive elements with a continuous drive film. An example is a Permalloy overlay consisting of a continuous drive film with protruding T & I bars which function as drive elements. This overlay structure is spaced over a suitable bubble material. The drive film is in direct contact with the T & I drive elements so that exchange coupling exists between the drive film and the drive elements. Use of a continuous drive film allows for control of the drive elements by a closed flux magnetic circuit having low power consumption.

Abstract: A device adapted for use in a low externally applied magnetic field, for example, 15 Oe, with a bubble lattice system is described. The device has a Y shaped channel in which bubbles are propagated between a bubble lattice column and either detector means or generator means. The magnetic pattern surrounding the Y shaped channel is controlled to yield a self biasing magnetic field which enables the device to retain the advantages of the close bubble packing in a bubble lattice for the detection and generation operations.

Abstract: A visual image display device with improved resolution contains a pair of conductive electrodes in spaced relationship. Adjacent one electrode is a first barrier layer which is typically a resin such as polyamide containing a readily oxidizable and reducible material such as zinc nitrate. Adjacent the other electrode is a thin film of solvent, for example, 1,2-dichloroethane. Positioned between the film of solvent and the first barrier layer is a second barrier layer which is a normally light transmitting recording medium. The second barrier layer is both photoionizable and capable of electrochemically producing a colored species. Typically the second barrier layer is a solid containing a resin such as polyvinyl butyral, an active material such as 1-p-anisyl-3 diethylamino styryl-5-diethylaminophenyl-2-pyrazoline and, in selected embodiments, an activator such as carbon tetrachloride.

Abstract: A method of treating the surface of substrates used in liquid crystal display cells so that the surface forces the alignment of the liquid crystal layer to be either parallel with the substrate wall or perpendicular to it. The method includes the step of forming free radicals of either oxygen or fluorine in a radio frequency plasma and exposing the glass or tin doped indium oxide (ITO) substrate to the reaction products of the plasma in such a manner that electron or ion bombardment is avoided. When oxygen radicals only are employed, the surface forces parallel alignment. When the oxygen treatment is followed by exposure to fluorine free radicals, the surface forces perpendicular alignment. To provide strong parallel alignment in reflecting liquid crystal display cells having metal, glass or ITO surfaces, the method consists of producing an oxygen plasma as described above and introducing either a volatile organo-silicon or an organo tin compound into the plasma.

Abstract: An erasable visual image display device contains a pair of conductive electrodes in spaced relationship. One electrode has a cation permselective membrane thereon and the other electrode has an anion permselective membrane thereon. Positioned between the two membranes is a recording medium having the properties of being both photoionizable and capable of electrochemically producing colored species. The medium contains an electrochemically reversible acceptor molecule, for example, 1, 2, 4, 5 tetracyanobenzene and an electrochemically reversible donor molecule, for example, 1-phenyl-3 diethylaminostyrl 5-diethylaminophenyl .DELTA..sup.2 pyrazoline.