Abstract: A sample-and-hold circuit is formed in bipolar transistor technology with the aid of clocked and complementary-clocked bipolar transistors in combination with a holding capacitor whose output terminal, in going from sample to hold phases of the clock, undergoes change in voltage .DELTA.V equal to the input voltage samples Vin applied to its input terminal during the sample phases (electrical bootstrapping operation). In particular, an input terminal of the holding capacitor is connected to a clocked input voltage device that ensures that, during the sample phases, the input voltage applied to the input terminal of the capacitor represents the input voltage being sampled, and that during the hold phases of the clock, the input terminal of the capacitor is electrically clamped. An output terminal of the holding capacitor is connected to one of the clocked transistors and to an auxiliary bipolar transistor whose base terminal is controlled by a complementary-clocked voltage-dropping device.

Abstract: This application discloses, to the best of our knowledge, the first unipolar laser. An exemplary embodiment of the laser was implemented in the GaInAs/AlInAs system and emits radiation of about 4.2 .mu.m wavelength. Embodiments in other material systems are possible, and the lasers can be readily designed to emit at a predetermined wavelength in a wide spectral region. We have designated the laser the "quantum cascade" (QC) laser. The QC laser comprises a multilayer semiconductor structure that comprises a multiplicity of essentially identical undoped "active" regions, a given active region being separated from an adjoining one by a doped "energy relaxation" region. In a currently preferred embodiment each active region comprises three coupled quantum wells designed to facilitate attainment of population inversion. In the currently preferred embodiment the energy relaxation regions are digitally graded gap regions. However, other energy relaxation regions are possible.

Abstract: The disclosed multi-pixel flat panel displays (e.g., flat panel field emission displays (FPFED) or liquid crystal displays (LCD)) includes spaced apart first and second electrodes, with a patterned solid material layer in contact with one of the electrodes, exemplarily between the two electrodes. The patterned layer (referred to as the "web") includes a multiplicity of apertures, with at least one (preferably three or more) aperture associated with a given pixel. In the aperture is disposed a quantity of a second material, exemplarily, a phosphor in the case of an FPFED, or a color filter material in the case of a LCD. The web can facilitate second material deposition by means of, e.g., screen printing, typically making possible formation of smaller phosphor or filter dots than was possible by prior art device. The web also can facilitate provision of spacer structure between the two electrodes, and can include getter or hygroscopic material.

Abstract: It has been found that fullerenes exhibit photoelectronic behavior such as photoconductivity or photovoltaic properties. Such behavior allows the fabrication of a variety of devices, such as solar cells and the use of various light-induced processes, such as the generation of a current by illumination of appropriate fullerene interfaces.

Abstract: In some circuitry, field effect transistors are produced by employing polycrystalline conductive regions including the channel and connections to the source and drain. Conventional methods for producing such transistors involve depositing a thin polycrystalline channel region, patterning this region overlying the patterned region with an insulator, producing openings in the insulator for contacts to source and drain, and depositing a thick polycrystalline contact region. Processing complexity is, however, substantially reduced by first forming interconnect areas, source region and drain regions; then opening a region for the channel; and finally depositing a layer to form the channel. Thus, at least three processing steps are eliminated and vertical dimensions are reduced.

Abstract: By using a specific polymer material for handling, shipping, and storage, integrated circuits are protected from both corrosion and electrostatic discharge. This enclosure material includes a polymer matrix with both carbon black and a metal embedded. Suitable metals include copper, iron, cobalt, and manganese.

Abstract: Selective epitaxy for indium phosphide in metalorganic chemical vapor deposition is possible by using a specific technique. In particular, a halogenated organic material is introduced with the InP precursors. This halogen-containing material should decompose to release halogen at approximately the same temperature that the metalorganic indium precursor decomposes. Through this process the manufacture of InP-based lasers is significantly enhanced and allows the use of reactive ion etching to form structures upon which InP regrowth is desired.

Abstract: A solder flux that is useful in applications such as surface mounting of components on printed circuit boards has been found. After soldering, the residue from the flux is either removable by water cleaning or requires no cleaning at all. The achievement of these desirable properties is accomplished by employing a solder flux vehicle including a removing agent, a low vapor pressure component, a high temperature component, and a rheological properties promoter.

Abstract: Fine lines (approximately 3 microns or less) are patternable on conductive materials by electromachining techniques. These micro-techniques differ from conventional electromachining in that the linewidth is primarily determined by the characteristics of the electric field rather than the electrode geometry.

Abstract: Optical amplifiers that are useful, for example, in optical communications are formed using a single crystal host waveguide and a dopant such as a transition metal. Through this combination, the amplified wavelength is adjustable and amplification at 1.3 .mu.m is possible.

Abstract: A class of resist compositions sensitive to deep ultraviolet radiation includes a resin sensitive to acid and a composition that generates acid upon exposure to such radiation. A group of nitrobenzyl materials is particularly suitable for use as the acid generator.

Abstract: Soldering is performed and the residues associated with the soldering process are removed through the use of a specific process. Components such as two integrated circuits or an integrated circuit and mounting board are initially tacked by compression bonding or through the use of adhesives. Flux is introduced, and the components to be soldered are brought to reflow temperature. The flux is chosen so that upon reflow and subsequent cooling to a temperature of 100.degree. C., or lower, the flux remains in liquid state. The flux is then easily removed by cleaning with a miscible liquid that is subsequently removed through processes such as spinning and evaporation.

Abstract: A one component resist material useful for deep ultraviolet, x-ray, and electron radiation has been found. Such material involves a substituent that is sensitive to acid and a moiety in the chain which both induces scission and provides an acid functionally upon such scission.

Abstract: A wide variety of products are formed by compression molding of silicone materials. Although such articles are used in numerous applications, compression molding is expensive and exudation of unreacted monomers and oligomers tend to cause electrical contact failures. By employing specific polyurethanes formed from polyols and isocyanates, it is possible to form articles by reaction injection molding. This process is substantially cheaper than compression molding and yet the same properties obtainable with silicones are attained.

Abstract: A mask for X-ray lithography is produced by initially forming a thin layer of polycrystalline silicon on a silicon oxide containing substrate. A portion of the substrate at the periphery of the major surface opposite the silicon layer is masked. The exposed portion of the substrate is removed by an etchant that is selective for silicon oxide containing composition relative to silicon, e.g. aqueous HF. The resulting membrane of silicon on a peripheral region of silicon oxide containing compositions is in tensile stress as required for lithography, but is robust. Metal, X-ray absorbing patterns are formed on the silicon by standard lithographic procedures.

Abstract: Electrical interconnections are made by means of a layer or sheet medium comprising chains of magnetically aligned, electrically conducting particles in a nonconducting matrix material. End particles of chains protrude from a surface of the medium, thereby enhancing electrical contact properties of the medium. The medium can be used for temporary as well as permanent connections; in the latter case the use of a nonconductive adhesive material is convenient for physical attachment to contacts on both sides of the medium.

Abstract: Paints and coatings involving semiconducting pigments such as titanium dioxide generally degrade because of oxidation of the binder by reactants that are photochemically produced on the pigment surface, and because of direct binder oxidation by charges that are photogenerated in the pigment. In titanium dioxide, this interaction is substantially reduced by avoiding reduced species and by introducing into the titanium dioxide trap states where photogenerated electron-hole pairs recombine by processes such as prolonged milling. Through these expedients, a substantial increase in the stability of the pigment containing composition is obtained.

Abstract: The use of alternating n and p type regions asymmetrically spaced in a semiconductor material yields extremely advantageous properties. In particular, by controlling the doping level and the spatial configuration of the doped region both the device response and its optical properties are controllable. Therefore, in applications such as those involving optical switches LEDs, lasers and long wavelength detectors, both the speed of device and its optical properties are controllable. As a result, greater fabrication flexibility than previously available is possible.

Abstract: Electronic devices such as hybrid integrated circuits such as those having test points spaced less than 1250 .mu.m are advantageously evaluated utilizing a two-probe process. In this process the probes are moved between test points in a pattern that reduces movement distance without concern for any ordering imposed by the nets themselves or the test to be made. Additionally, the test is made so that the movement time is the limiting factor.

Abstract: A hermetically coated optical fiber is produced by contacting a hot fiber with an organic material such as acetylene. The heat of the fiber causes decomposition and results in a hermetic, carbonaceous coating. This coating is essentially impermeable to both water and hydrogen.