Abstract: A method and apparatus for testing very large scale integrated circuit devices, most particularly Level Sensitive Scan Design (LSSD) devices, by applying differently configured sequences of pseudo-random patterns in parallel to each of the input terminals of the device under test, collecting the output responses from each of the output terminals in parallel, combining these outputs to obtain a signature which is a predetermined function of all of the sequences of parallel outputs and comparing the test signature with a known good signature obtained by computer simulation. The input test stimuli are further altered in a predetermined fashion as a function of the structure of the device to be tested, to individually weight the inputs in favor of more or less binary ones or zeros.

Abstract: A method and apparatus for aligning a ceramic substrate provided with two small alignment crosses formed at the same time as the metallic pattern and located on both sides of a symmetry axis, said substrate being disposed on an alignment platen. The method includes the steps of generating in two insepection windows, comprised each of a matrix of photodiodes divided into quadrants i (i=1, 2, 3, 4), a reference image of the same dimensions as the image of each cross, and determining, for each quadrant and for each cross, "exposed" areas (S.sub.i.sup.+, S.sub.i.sup.+ ') corresponding to those portions of the image of the cross which extend beyond the outline of the reference image, and "masked" areas (S.sub.i.sup.-, S.sub.i.sup.- ') corresponding to those portions of the reference image which extend beyond the outline of the image of the cross. The values of said areas are used to compute the corrections (.DELTA.x, .DELTA.y; .DELTA.x', .DELTA.

Abstract: A phase splitter with latch comprises a true complement generator in the form of a current switch (T1, T2, T3, R3) which supplies two complementary output signals in response to an input signal (VIN). The outputs of this true complement generator are in each case connected to an associated emitter follower (T4, T5). The two emitter followers (T4, T5) have identical emitter resistors (R6, R7) which simultaneously serve as collector load resistors of two cross-coupled transistors (T6, T7) also comprise identical but higher emitter resistors (R13, R14) than the emitter followers (T6, T7). The emitters of the cross-coupled transistors (T6, T7) are each connected to one of the two inputs of an output stage (T8, T9, T11) consisting of a current switch. This current switch is connected to operating voltage (VEE) through a clock-controlled transistor (T11). Upon actuation of the output stage, i.e.

Abstract: A magnetic tape recording and playback system having a tape cassette and battery pack joined by a frangible connection in an integral assembly, wherein for recording the assembly provides battery power to the recorder and the recorder provides recording signals to the cassette, and for playback, the battery is broken away from the cassette and discarded and the cassette is inserted into the playback unit, which can accept only the cassette without the battery. This prevents re-use of the cassette in the recorder and assures the use of a fresh battery for each recording session.

Abstract: A semiconductor wafer shape which when subjected to a simultaneous polishing of both wafer surfaces produces a wafer of superior flatness and surface finish, the said wafer having a diametral cross-sectional shape like that of a "dogbone" wherein the wafer is thinner in its medial region than it is in the peripheral region and has rounded edges, this shape resulting from a chemical thinning operation.

Abstract: The method is comprised of the following steps:implanting arsenic ions through a thin screen oxide layer in the regions of a P type silicon substrate where subcollectors are to be formed, at a dose less than 2.10.sup.16 at/cm.sup.2, partially etching said screen oxide layer to remove the upper portion, containing contaminating ions exposing to an oxygen ambiant to approximately reconstitute original thickness of the screen oxide layer and then annealing in an inert atmosphere, the substrate, to heal damages and distribute arsenic atoms in the substrate. It has been discovered that the step of reconstituting the original thickness of the screen oxide layer in an oxygen ambient, has the unexpected effect of permitting the subsequent growth of an absolutely defect free epitaxial layer.

Abstract: The photoresist film 12 on the surface of a wafer 11 is exposed through the shadow pattern which is generated by a transmission mask 13 arranged a short distance therefrom when the mask is subjected to a large-area electron beam. The source of the electron beam is an unstructured photocathode 16 on an ultraviolet transparent carrier such as, quartz glass 17 which is subjected to UV radiation from the backside. The electrons exiting from layer 16 are accelerated by a homogeneous electric field 14 towards the mask 13 and shaped to form a homogeneous collimated electron beam. By means of laterally positioned electrostatic deflecting electrodes 19a, 19b, the entire electron beam can be tilted relative to the wafer for adjusting the mask pattern.

Abstract: A probe head arrangement for contacting a plurality of closely adjacent conductor lines 2 comprises a minimum of one probe head 3, where a plurality of fingers 4 together with a back 5 are made in one piece of monocrystalline silicon in semiconductor technique. A plurality of such probe heads 3 are composed to form a tester. At the beginning of each test it is determined which fingers 4 are to be, and are not to be placed onto the individual conductor lines 2 of a card 1 to be tested. Subsequently, the short and interruption tests can be implemented after the correlation of finger and probe head addresses with the conductor line addresses.

Abstract: An improved method of growing silicon crystals by the Czochralski method to obtain a desired oxygen concentration level with both axial and radial uniformity. A crucible is located within a heater to achieve a given temperature profile which is related to the oxygen concentration, and then raised and rotated at an increasing speed together with a high crystal rotation rate to achieve the uniformity.

Abstract: Apparatus consisting of combinations of interconnected logic elements for generating preselected sequences of addresses for the listing of a matrix memory as a function of preset constants and variable timing impulses, wherein there are first and second X and Y address generators with controlled selection means for selecting the first or the second of the X and Y address pairs, each of the address generators being settably controllable to generate a preselected sequence of addresses in ascending or descending order, with settable increments within the sequence, settable masking, and settable displacements from a fixed reference origin.

Abstract: The travelling support (1) comprises a piezo-electric plate (2) resting on three legs (6) whose bottom surface is insulated from the bench (8) on which the support is to travel, by a dielectric (7). The piezo-electric plate (2) can be caused to contract by means of an actuating voltage applied via sliders (9, 10) to top and bottom electrodes on the plate (2). By applying a voltage to the legs (6), these may be clamped selectively by electrostatic forces effective across the dielectric (7). Appropriate control of the actuating and clamping voltages causes the support (1) to either move in a linear or rotary fashion. The displacements the support can perform per step are in the nanometer range.

Abstract: On the layer 12 a mask 3 corresponding to the desired pattern of holes 15 is provided with via openings 14 having overhanging walls. The layer 12 is selectively etched with a method where the etching attack takes place vertically to the layer surface, and wherein the mask 3 is thinned simultaneously, so that holes 15 are obtained having a cross-section increasing toward the mask 3. If subsequently material 16 for filling the holes 15 is applied in a blanket deposition these holes are completely filled when the material 16 has the same thickness as the layer 12 although the openings over the holes are decreasing with increasing thickness of the material 16. The layer 12 consists preferably of an insulation material, the mask 3 of positive photoresist, and the material 16 of a metal.

Abstract: A semiconductor laser and optical waveguide are coupled together along a common optical axis and bounded at remote ends with reflective surfaces to form an optical resonant cavity. A periodic grating formed in a side surface of the optical waveguide directs some radiant energy out of the cavity in a direction not parallel with the common optical axis.

Abstract: A scanning apparatus for converting an optical line image to a serial electrical analog signal by launching an acoustic wave in a plurality of ridged waveguides each of a different length. In one embodiment the launching transducer includes an electro-optical layer which modulates the acoustic wave as a function of the incident light intensity. In a second embodiment the acoustic wave is launched in each waveguide with the same amplitude but interacts with an acousto-optical overlay on the waveguide to amplitude modulate the intensity of the propagating acoustic wave. The thus generated and modulated acoustic waves are converted to electrical signals either by reflection back to the launching transducer or by individual transducers on each channel. The differing lengths converts the parallel image to a series electrical signal.

Abstract: An optical assembly structure wherein miniature optical components such as lasers, modulators, lenses, thin-film and fiber-optic waveguides, and photodetectors are critically aligned and supported for coactive operation by means of two or more wafers which are formed with complementary grooves and mortises to support the loose optical components such as lenses and fiber-optic waveguides and to receive alignment rails to insure the relativity of the wafers, which also have formed integral therewith optical elements such as waveguides, modulators, and lasers, to produce an integrated optical assembly somewhat in the manner of an "optical bench," wherein the bench structure also provides an active optical element.

Abstract: This memory management system provides an improved search logic for locating pages of data stored parallel-by-bit, serially-by-page in a shift register memory and for moving those pages to a position at the head of the file. Searching alternates between forward and reverse with a first direction change occurring when the head of the file occupies an input/output station in the memory and a second change occurring when the last of a plurality of pages identified for search at the first reversal position is found.The page numbers of three sought data pages are entered into three search registers and compared with the page number of each page as it is shifted into the input/output station of the memory. A page number is replaced when the page is found. Page numbers are marked with a binary one upon each direction change at the first position and with a binary zero at each replacement of a page number at other than that position.

Abstract: An array of collimated wise aperture electrically pumped leaky corrugated AlGaAs optical waveguide lasers is formed on a single chip by etching a series of grooves oriented with respect to the crystalographic planes to isolate discrete lasers in the array and provide the requisite orientation of the internal reflecting surfaces to support the lasing action. The corrugation period is chosen such that the laser radiation exits from the array in a direction normal to the plane of waveguide.

Abstract: Apparatus for controlling the division of working memory space among n competitive programs with different characteristics, running in a multiprogramming and virtual memory environment, in which the allocation of working space is optimized by adjusting the size of the working set for each competing program. Under this optimization scheme, "the value of a page frame" (the amount of reduction in the page fault rate if an additional page frame is allocated to that program) is sought to be equalized for all programs. Every memory access increments an access counter. When it reaches its maximum count of 1024, the reference register value stored in an associative memory for each page is incremented by one count, except that for the page accessed it is reset to zero. The stored numbers range from 0 to 31. Whenever a page fault occurs, the number of pages of that program having a reference register count equal to each of the numbers 0 to 31 is temporarily stored as a table of 32 Wd values.

Abstract: A data communication network having a plurality of nodes interconnected with a communication link, wherein each node shares given ones of its data sets in common with other nodes in the network, and each node is operative to update any shared data set, except if one of the other nodes is also seeking to update the same data set, in which case the node having the higher priority prevails. Each node has a memory which stores the node location of each shared data set and the updating priority which each node has with respect to each respective set of shared data. A node receiving competing requests for update will access this memory and, depending upon the sequence of the requests, may accept a higher priority request and refuse a lower priority request.

Abstract: An injection laser, whose sides are chemically etched to produce facing 45.degree. mirrors, can be made to emit lasing light in the same direction as current going through the p-n junction. A two dimensional array of lasers is produced wherein the location of each laser is uniformly spaced from an adjacent laser.