Abstract: A method for producing topographic projections, especially useful for producing many small projections of less than about 100 &mgr;m in diameter and in height. This method is useful for making contact pads of membrane probes used to test integrated circuits and spacers of liquid crystal light valves.

Abstract: A method for fabricating resilient z-axis contacts to electrically interconnect IC wafers or MCMs in 3-D integrated circuits uses photolithography to provide larger carrier sizes, higher contact densities by decreasing the spacing, smaller contact footpads, and precise control of the contact's shape and position. The contacts are fabricated by forming photoresist patterns on the carrier's top and bottom surfaces that are initially rectangular, and then reflowing the photoresist materials to provide smooth surfaces suitable for forming the metal contacts, and depositing metal layers over the respective patterns. Second photoresist patterns are formed over respective metal layers to conform with the contact's shape, the metal is etched away according to the pattern, and the photoresists are removed such that the remaining metalization forms a resilient z-axis contact that is attached to the carrier and extends therefrom with a predetermined shape.

Abstract: A substrate (20) is treated prior to use to induce a near-perpendicular orientation of a liquid crystal director (26) relative to the substrate. A layer of silica (98) is deposited upon the substrate (20) by in-line magnetron sputtering as the substrate ( 20) is moved past the sputtering target (78), and the silica-coated substrate (20) is thereafter treated with a long-chain alcohol. The alcohol-treated substrate (20) is covered with a layer of liquid crystal (22), the director (26) of the liquid crystal (22) assuming a field-off state tilted about 1-3 degrees from the perpendicular toward an azimuthal direction (30) parallel to the direction of movement of the substrate (20) during deposition.

Abstract: A system and method for fabricating optical ramp filters utilizes an ion beam sputter etching system and a shaped aperture mask to produce optical ramp filters with precise control over the transmission and reflectance properties of the filter. The ion beam is passed through a shaped aperture whose width varies as a function of its length. The resultant shaped ion beam is used to etch a uniform reflective layer that was previously deposited on a transparent substrate. The substrate and the reflective layer are translated relative to the shaped aperture so that the shaped ion beam "travels" across the reflective layer. Different parts of the reflective layer are exposed to the ion beam for different amounts of time as a result of the varying width of the shaped ion beam. The result is a reflective layer with a nonuniform depth profile (a ramp filter). The method allows control of the layer thickness with a precision of less than 0.5 nm.

Abstract: A process is provided for modifying a surface of a large area, non-planar substrate to form micro structures therein that alter its optical properties. The process includes forming the micro structures by reactive ion beam etching through a chosen pattern that has been prepared on the surface.

Abstract: A substrate (20) is treated prior to use to induce a near-perpendicular orientation of a liquid crystal director (26) relative to the substrate. A layer of silica (38) is deposited upon the substrate (20) by in-line magnetron sputtering as the substrate (20) is moved past the sputtering target (78), and the silica-coated substrate (20) is thereafter treated with a long-chain alcohol. The alcohol-treated substrate (20) is covered with a layer of liquid crystal (22), the director (26) of the liquid crystal (22) assuming a field-off state tilted about 1-3 degrees from the perpendicular toward an azimuthal direction (30) parallel to the direction of movement of the substrate (20) during deposition.

Abstract: A 3-D IC chip assembly is formed from stacked substrates in which each individual substrate has a plurality of different IC chips retained in respective recesses. Conductive feedthroughs extend through the substrate from the side where the chips are located to the opposite side, with the chips electrically connected to the feedthroughs. An electrical routing network on the opposite side of the substrate from the chips provides desired interconnections between the chips by connecting to the feedthroughs. The routing can be formed by standard photolithographic techniques.

Abstract: A reflector and method for fabricating diffraction gratings in reflectors comprises the steps of placing one or more layers (38, 56-64) of a dielectric reflective enhancing material on a reflective surface (34, 54), and forming grooves (40, 66) only in the top layer (38, 64) of the dielectric material to form the gratings. Precise control of the efficiency is obtained by decreasing the thickness (b', b") of the grooved layer and adjusting the ratio (b'/b") of the material under the grooves and adjacent to the grooves.

Abstract: The present invention provides a method of preparing the surface of a lithium niobate substrate (10) having titanium optical waveguides (12) for a subsequent deposition of a coating material such as electrodes. This cleaning or etching step prior to the deposit of desired coating materials is accomplished without deterioration of the transmission capacities of the optical waveguides (12). The substrate cleaning step of the present invention comprises the introduction of a predetermined amount of oxygen (16) at a controlled rate to provide a predetermined atmospheric environment surrounding the lithium niobate substrate (10). The subsequent etching of the substrate surface to a predetermined depth, for example, by argon ion bombardment, provides minimal damage to the optical waveguides while still producing an excellently cleaned surface preparatory for receiving subsequent layer depositions such as the electrodes.

Abstract: A thin film polarizer for dividing electromagnetic energy into two mutually orthogonal components with a high degree of selectivity. A plurality of wire grids having an interelement spacing of less than one wavelength is supported by a substrate of electrically insulative material. The substrate is invisible to the wavelength of the polarized electromagnetic energy. The planar wire grids are substantially parallel and spaced less than one wavelength therebetween to achieve an efficient and compact thin film polarizer. The process of this invention for forming the plurality of wire grids comprises photolithographically defining each grid layer by the interference pattern of at least two coherent beams such as laser beams, one forming step being required for each grid, an anti-reflective layer being inserted between adjacent grid layers.

Abstract: Electrode surfaces are coated with a passivating material (silicon dioxide, aluminum oxide or titanium dioxide) or with a reflecting material (chromium or chromium and gold) or with a special alignment material (carbon) using standard vacuum sputtering, vacuum evaporation, electrodeposition, or chemical vapor deposition techniques. After sufficient thickness of material has been deposited, the substrate is exposed to a broad or narrow beam of neutralized argon ions of a few kilo-electron-volts energy. The beam of argon ions is incident at a grazing angle to the surface, typically 20.degree.. Exposure of the overcoating results in a microscopic condition believed to comprise a "corrugated" surface with "ridges" and "valleys" parallel to the direction of the incident beam.

Abstract: Disclosed is a process for fabricating small geometry electronic devices, including a variety of integrated optical devices. The process includes the steps of holographically exposing a resist masking layer to a plurality of optical interference patterns in order to develop a masking pattern on the surface of a semiconductive body. Thereafter, regions of the body exposed by openings in the masking pattern are ion beam machined to thereby establish very small dimension undulations in these regions. These closely spaced undulations have a variety of uses in optical devices as will be described. The present invention is not limited to the geometry control of semiconductive structures, and may also be used in the geometry control of metallization patterns which have a variety of applications, or the geometry control of any ion beam sensitive material.

Abstract: Millimeter-wave electronic devices are produced first by micromachining an epitaxial layer on a substrate wafer to a precise thickness by directing an ion beam over the epitaxial layer. Any bombardment damage is removed by a light chemical etch. Thereafter, an insulative layer with a mask is placed over the micromachined epitaxial layer and the ion beam is broadly directed onto the masked wafer to micromachine precise holes through unmasked portions of the insulative layer. Micromachining may proceed until approximately 500 A thickness of the insulative layer remains, this remaining layer being removed by a brief chemical etch to expose the underlying epitaxial layer. Alternatively, in cases where a slight recess into the semiconductor is desired to alter the electric field lines at the interface between the oxide and the semiconductor, the ion beam may be permitted to etch completely through the oxide film and into the epitaxial layer to the desired depth.