Abstract: A method for lithographic alignment utilized in the manufacture of integrated circuits is described. The procedure includes an initial calibration through the lens system to expose a calibration material in a diffraction grating pattern. An interference pattern is produced above the grating with intersecting laser beams. By adjusting the path and/or phase of these beams the interference pattern is aligned with the diffraction pattern to establish a calibration point corresponding to a reference intensity in the intensity of the diffracted light. A wafer to be exposed is then placed in the exposure tool and is aligned by observing the diffraction pattern from a diffraction grating fiducial mark induced by the calibrated interference pattern.

Abstract: A new class of silicon compounds having a high percentage of silicon atoms bonded to three other silicon atoms has been synthesized. These materials denominated polysilynes form smooth amorphous films which have quite useful properties. For example, photooxidation produces a refractive index change from 1.70 to 1.45. Similarly, photooxidation also produces a substantial change in solubility. Thus the materials are useful for the fabrication of optical and electronic devices.

Abstract: Anisotropic plasma etching is accomplished utilizing a helical resonator operated at relatively low gas pressure. The use of this combination yields an extremely high flux of ionic species with resulting rapid anisotropic etching. A helical resonator in conjunction with suitable precursors is also quite useful for plasma induced deposition.

Abstract: A relatively inexpensive and relatively efficient coupler is obtained by connecting two fiber collections with a polymer material, provided the numerical aperture of the two collections are relatively well-matched to each other and to the polymer region. This efficiency is achieved despite relatively large mismatches in the refractive index of the resin material relative to the fibers. Couplers for optical backplanes are produced in one embodiment utilizing plastic materials. In this technique, a collection of fibers is inserted on each end of an enclosure such as a tube that is filled with a polymer that is subsequently cured.

Abstract: A preform for fabrication of a glass fiber optical transmission line is prepared by chemical reaction of vapor ingredients within a glass tube. Reaction, which may be between chlorides or hydrides of, for example, silicon and germanium with oxygen, occurs preferentially within a constantly traversing hot zone. Flow rates and temperature are sufficient to result in glass formation in the form of particulate matter on the inner surface of the tube. The particulate matter deposits on the tube and is fused with each passage of the hot zone. Continuous rotation of the tube during processing permits attainment of higher temperatures within the heated zone without distortion of the tube.

Abstract: Gas phase processes such as plasma etching of a semiconductor substrate is monitored by utilizing the optogalvanic effect. The substrate is subjected to light and in response emits an electron current whose magnitude is representative of the composition at the surface of the substrate. The monitored current is a sensitive indication of surface contamination and of compositional changes associated with the gas phase procedure. The technique is effectively utilized in fabricating devices such as semiconductor devices.

Abstract: Reactive ion etching of the planarizing layer of a multilevel resist structure utilized to make integrated-circuit devices is carried out employing a plasma derived from carbon dioxide. The etching step is characterized by high throughput, good linewidth control, negligible radiation damage and low sensitivity to process parameter variations.

Abstract: Extremely useful compositions for delineation of materials utilized in device applications have been found. These compositions include a polymer having segments that are at least 10 monomer units long of a first entity and segments again at least 10 monomer units long of a second entity. The monomer units are chosen so that each segment type provides a specific chemical characteristic to the polymer.

Abstract: Printed circuit boards having a plurality of circuit layers are produced using a specific processing sequence. A copper-clad substrate is first patterned in a desired configuration to produce the first layer of the printed circuit board. The patterned metallization is then covered with a specifically formalated energy sensitive material. The energy sensitive material is delineated in a desired pattern and developed to uncover portions of the underlying metallization pattern. The entire substrate is blanket-cured to produce a rigid layer having openings in appropriate places. The openings are metallized and a second copper pattern is produced on the cured polymer by conventional metallization and lithographic techniques. If desired, the process is repeated until a suitable number of copper patterned levels are obtained.

Abstract: Certain semiconductor device structures are described in which single crystal layers of cubic Group II fluorides cover at least part of the surface of III-V semiconductor compound. The fluoride crystal has a cubic structure and may be lattice matched or lattice mismatched to the compound semiconductor substrate depending on fluoride composition. These fluoride single crystal layers are put down by a moleuclar beam epitaxy procedure using certain critical substrate temperature ranges and a particular cleaning procedure.

Abstract: The operation of neural networks begins with the initialization of the system with the information to be processed. Presently, this initialization is performed by pinning the system with rather large analog or digital signals representing this information. The problems associated with the high power required for such initialization are eliminated and accuracy is maintained by utilizing a specific set of input points and appropriately positioned switches. In particular, a switch corresponding to each amplifier is introduced, and the initializing data is introduced between the amplifier and this switch.

Abstract: By adjusting the AC field conditions, i.e., by grounding the environment of a substrate being etched with a chlorine-containing plasma, a significant increase in etch selectivity is achieved. By applying a similar AC field adjustment to the reaction chamber surfaces, excellent etch uniformity is achieved in conjunction with excellent selectivity.

Abstract: Certain semiconductor device structures are described in which single crystal layers of cubic Group II fluorides cover at least part of the surface of III-V semiconductor compound. The Fluoride crystal has a cubic structure and may be lattice matched or lattice mismatched to the compound semiconductor substrate depending on fluoride composition. These fluoride single crystal layers are put down by a molecular beam epitaxy procedure using certain critical substrate temperature ranges and a particular cleaning procedure.

Abstract: Excellent ordering in ferroelectric liquid crystal devices is obtained by utilizing a material having a smectic C phase and no higher temperature orthogonal smetic phases. Ordering is accomplished by the combination of (1) contacting the liquid crystal material in the smectic C phase with an ordering substance and (2) subjecting the liquid crystal material to a slowly varying electric field.

Abstract: The invention is a controlled laser having an optical resonator, a laser gain medium placed inside the optical resonator, the laser gain medium being capable of emitting light and of lasing with the light, a multiple layer heterostructure placed inside the optical resonator, and means for varying an optical absorption of the multiple layer heterostructure for the light in order to control an optical gain of the optical resonator, and thereby control lasing of the laser gain medium. Passive mode locking is achieved by the light emitted by the gain medium controlling the optical absorption of the multiple layer heterostructure. Active mode locking and modulation are achieved by controlling the optical absorption of the multiple layer heterostructure by applying an electric field to the multiple layer heterostructure.

Abstract: An electrooptic or optical parametric device comprises a noncrystalline second order optically nonlinear element and means for providing an optical input to and an optical output from said element wherein said element comprises an organic molecule having second order optical susceptibility incorporated in a directionally oriented manner in an optically clear glassy polymer. When said device is employed in an electrooptic mode it includes means for applying an electric field and/or optical input to said element for altering an optical property thereof.

Abstract: The extent of loss produced in fibers due to the presence of OH infrared absorption bands is significantly reduced through the use of specific expedients during, for example, the preform collapse procedure. In particular, during this procedure a carbon tetrahalide composition is employed to essentially prevent the presence of any residual hydrogen-containing entity from influencing the quality of the preform and thus from influencing the quality of the fiber ultimately produced.

Abstract: In dielectrically isolated devices a buried conducting layer adjacent to the dielectric layer is produced by a drift effect. In particular, if arsenic antimony and/or phosphorus is present in the silicon dioxide layer, it is caused to drift from this layer and enter the adjacent isolated silicon region while maintaining a relatively narrow spatial configuration. Thus, a discrete buried highly conductive layer is formed. This configuration is particularly useful for transistor configurations such as utilized in switching applications.

Abstract: Distributed region optical sensors for chemical detection are provided by utilizing optical fiber technology. A core is provided with a surrounding region that is permeable to the chemical to be detected. A composition whose optical characteristics are altered upon interaction with the chemical to be detected is provided within the permeable material. This change in optical characteristics allows chemical detection through detection of light guided by the fiber.

Abstract: A sol-gel process is utilized for producing silicon oxide glasses useful in the manufacture of devices such as semiconductor devices. These glasses are easily deposited by techniques such as spinning. Not only is the glass easily applied, but also has advantageous electrical, etching, and mechanical properties. Thus, these glasses are useful in applications such as passivating layers for integrated circuit devices and as intermediary layers in trilevel lithography for the production of such devices.