Abstract: A method for cleaving semiconductor wafers, or segments thereof, which comprises placing the wafer, provided with scribe lines defining the planes where cleaving is to take place, inbetween a pair of flexible transport bands and guiding it around a curved, large radius surface thereby applying a bending moment. With a moment of sufficient magnitude, individual bars are broken off the wafer as this is advanced, the bars having front-and rear-end facets. On cleaving, each bar, while still pressed against the curved surface, is automatically separated whereby mutual damage of the facets of neighboring bars is prevented. For further handling, e.g. for the transport of the bars to an evaporation station for passivation layer deposition, provisions are made to keep the bars separated. Cleaving and the subsequent passivation coating can be carried out in-situ in a vacuum system to prevent facet contamination prior to applying the passivation.

Abstract: A method, and device produced therewith, for improving the planarity of etched mirror facets 18 of integrated optic structures with non-planar stripe waveguides, such as ridge or groove diode lasers or passive devices such as modulators and switches. The curvature of the mirror facet surface at the edges of the waveguide due to topographical, lithographical and etch process effects, causes detrimental phase distortions, and is avoided by widening the waveguide end near the mirror surface thereby shifting the curved facet regions away from the light mode region to surface regions where curvature is not critical.

Abstract: A method, and device produced therewith, for improving the planarity of etched mirror facets 18 of integrated optic structures with non-planar stripe waveguides, such as ridge or groove diode lasers or passive devices such as modulators and switches. The curvature of the mirror facet surface at the edges of the waveguide due to topographical, lithographical and etch process effects, causes detrimental phase distortions, and is avoided by widening the waveguide end near the mirror surface thereby shifting the curved facet regions away from the light mode region to surface regions where curvature is not critical.

Abstract: A process for forming sidewalls for use in the fabrication of semiconductor structures, where the thin, vertical sidewalls are "image transferred" to define sub-micron lateral dimensions.First, a patterned resist profile with substantially vertical edges is formed on a substrate on which the sidewalls are to be created. Then, the profile is soaked in a reactive organometallic silylation agent to silylate the top and the vertical edges of the resist to a predetermined depth, thereby rendering the profile surfaces highly oxygen etch resistant. In a subsequent anisotropic RIE process, the horizontal surfaces of the silylated profile and the unsilylated resist are removed, leaving the silylated vertical edges, that provide the desired free-standing sidewalls, essentially unaffected.

Abstract: Process for producing temperature-stable undercut profiles for use in semiconductor fabrication. The process is based on the phenomenon of high etch-rate selectivity between RF- and LF- PECVD-grown silicon nitride films (12G and 13G, respectively) that are deposited on top of each other. By choosing proper film and process parameters, these PECVD nitride structures can be made stress-free: the tensile stress of the RF film (12G) compensates the compressive stress of the LF film (13G).Also disclosed is an application of a T-shaped structure (15), produced with the new process, in a method for fabricating fully self-aligned "dummy" gate sub-micron MESFETs.

Abstract: According to this process two partial patterns which, if superimposed upon each other in a predetermined alignment relative to each other yield the desired pattern, with elements of both partial patterns combining to form elements of the pattern, and these partial pattern elements overlapping sectionally, are projected with a suitable radiation onto the radiation-sensitive layers. Overlapping is achieved in that when designing the two partial patterns a pattern corresponding to the desired pattern is used as a basis in that the elements of this pattern are exposed to a negative windage, the negative windage pattern is subsequently partitioned into two negative windage patterns corresponding to the partial patterns, and finally the negative windage partial pattern elements are exposed to a positive windage to the desired size of the partial pattern elements.The method is used in particular when a pattern is to be transferred by means of hole masks, and if it is necessary, e.g.

Abstract: Planar junction Josephson interferometer in which the junctions (24) are "buried" underneath the interferometer bridge (27) connecting the junction counter-electrodes (25). The insulation (26) that separates the common base electrode (22) from the bridge (27) is extended between the bridge and the upper surfaces of the counter-electrodes. This design permits, without decreasing the interferometer loop inductance, a reduction of the interferometer area and thus results in a higher packaging density in logic or memory applications.The buried junction concept can be applied in symmetric or asymmetric interferometer designs with virtually any number of junctions, any type of input current control or current feeding scheme.The interferometer can be produced using conventional evaporation, photo-resist, and etch processes based on optical lithography. Further area reduction is achieved in applying e-beam or x-ray technology.

Abstract: A system to improve the uniformness of patterns for LSI circuits or masks generated in an electron beam lithographic system uses a backscatter indicator signal to vary a control signal for the beam stepping rate proportional to the variations in the amount of backscattered electrons. This avoids non-uniformity such as line width variations which otherwise occur when the pattern to be generated covers border lines between two different substrate or base layer materials. Range setting circuitry is provided for adjusting, during an initial prescan of a sample of two materials having an extreme difference in their backscatter characteristic, the offset and the gain for the backscatter detector. During subsequent exposure of a wafer, the backscatter indicator signal and thus the stepping rate control signal variations remain within preselected limits.

Abstract: An electron beam fabricated mask used in the production of integrated circuits is tested by a method that includes the steps of forming a print of the mask and then inspecting the print by writing the same electron beam pattern or complement thereof on the print and detecting pattern coincidence and non-coincidence with a vector scan system.

Abstract: An arrangement for separating disturbing ambient light from an optical data signal, comprising an interference filter (1), the passband of which matches the wavelength of the optical data signal, and further comprising two photodiodes which are so arranged that one photodiode receives the light (I.sub.S, I.sub.AT) transmitted through the interference filter, and that the other receives the reflected light (I.sub.AR). Adjusting means, e.g., in the form of a settable aperture (4) or an additional simple filter (5) are provided for adjusting the transmitted and reflected portions of the ambient light to each other. Output signal (S1, S2) of both photodiodes are subtracted from each other in compensation circuitry (6). This results in compensation of the ambient light components so that at the output a signal (SR) is available which depends only on the actual data signal (I.sub.S).

Abstract: For the multiplex transmission of coded speech signals in periodic frames, single segments (blocks of coded samples) are selectively suppressed for redundancy reduction, and are replaced on the receiver side by optimally correlated subsections of equal length from previously transmitted segments. On the transmitter side, a multiplicity of compare operations are made for each speech signal, between the respective newest coded segment and a step wise shifted subsection window of previous segments, to determine the best correlated subsection, i.e. the one which is most suitable as replacement and the respective relative offset and correlation. From a group of speech signals, the one signal, or several signals, having the best correlation is selected for suppression of a segment before transmission. Instead of each missing segment an indication of the corresponding optimum offset is transmitted in the frame header.

Abstract: In an extension line circuit, an off-hook condition is detected during ringing by superimposing in each ringing cycle the values of the line current existing at two sampling instants exactly one-half cycle apart, and testing whether the sum (or mean value) exceeds a given threshold. When DC current starts flowing due to the set going off-hook, the mean value of the two values will pass a threshold.Sample pulses for the sampling instants can be derived in common for all line circuits from positive-going zero crossings of the ringing supply signal.

Abstract: This invention comprises a telephone hybrid circuit having two opto-coupler arrangements for transferring voice signals from the two-wire line to a port of the switching system on one hand and from a port of the switching system to the two-wire line on the other hand. In addition, a pair of feeder circuits in the form of current sources comprising active elements are provided for feeding a constant positive direct current to one wire of the two-wire line and a negative direct current of equal magnitude to the other wire of the two-wire line. Each of the current sources includes control circuitry for maintaining a constant ratio between the current furnished by the current source and a control current common to both current sources. A control current path is connected to the output of one of the opto-coupler arrangements for generating a common control current in response to a dc signal and a superimposed voice signal received from a port of the switching system.