Abstract: A process is provided for fabricating self-aligned contacts to the surface of an integrated circuit. The process includes the steps of depositing a layer of silicon dioxide 12 on the surface of a semiconductor structure 10; depositing a layer of polyimide 15 on the surface of the silicon dioxide 12; defining openings 23 in the polyimide material 15 and the silicon dioxide 12 to thereby expose regions of the semiconductor structure 10; and depositing metal 22 across the underlying surface and in the openings 23. In the preferred embodiment metal 22 is substantially the same thickness as silicon dioxide 12, and polyimide material 15 is masked using sequentially deposited layers of silicon dioxide 18 and photoresist 21.

Abstract: A lateral bipolar transistor having a base width of 0.

Abstract: A semiconductor structure is fabricated using a process involving all ion implantation and using only five masks prior to metallization. A buried contact mask is used to form a buried contact layer (114), an isolation mask is used to form grooves (130a, 130b) in an epitaxial layer of silicon (113), a self-aligned transistor mask is used to form a mask (134a to 134e) to define the areas in which emitters (138a, 140b, 140c) bases (113, 139) and contact regions (140a) are to be formed, a base exclusion mask (135a,b) is provided to exclude certain impurities from being implanted into a region to be formed of one conductivity type, and a second exclusion mask (137a, 137b) is provided to exclude impurities to be implanted in a region of opposite conductivity type from the prohibited regions of the structure.

Abstract: In a semiconductor device, laser energy is used to selectively heat various SiO.sub.2 and/or GeO.sub.2 based materials to elevated temperatures while maintaining the active device region and electrical interconnects at relatively low temperatures, to for example, induce densification and/or flow of the SiO.sub.2 and/or GeO.sub.2 based material to round off sharp edges and stops, without damaging or affecting the active region and electrical interconnects.

Abstract: A process and structure are disclosed which are suitable for forming large arrays of Schottky diodes at desired locations between mutually perpendicular strips of aluminum and strips of metal-silicide. The invention is particularly useful in creating read-only memories and programmable logic arrays, and allows fabrication of Schottky diodes more compactly than previous structures.

Abstract: A self-refreshing non-volatile memory cell having two cross-coupled transistors includes a first floating gate formed between the gate and the channel of said first transistor, said first floating gate overlying by means of a tunnel oxide a portion of the drain of said second transistor and a second floating gate formed between the gate and channel of said second transistor, a portion of said second floating gate overlying by tunnel oxide a portion of the drain of the first transistor. Disturbances in the supply voltage and the gate voltage of the device normally enhance rather than degrade the state of data stored in the cell, thereby providing an extremely long storage time for the cell. The cell is capable of operating simultaneously in a volatile and a non-volatile state.

Abstract: A method and apparatus is described for dynamically testing the overall performance characteristics of digital-to-analog converts and analog-to digital converters which involve excitation of the converters by an orthogonal function signal. Specifically the method comprises dynamically exercising a converter with an analog or digital signal pattern characterized by the sum of a set of mutually orthogonal functions, the sum having substantially uniform amplitude distribution among allowable states (maximum entropy), and simultaneously examining the output response of the converter for a plurality of basic performance parameters. The basic performance parameters typically include distortion, linearity and optimum gain. The simultaneous examination involves sorting out expected responses to simultaneously applied orthogonal signals. The method yields a relatively complete statistical description of the performance characteristics. The preferred excitation is based on the Walsh functions.

Abstract: An integrated circuit structure and process for fabricating it are described which allow fabrication of a very compact high-speed logic gate. The structure utilizes a bipolar transistor formed in an epitaxial silicon pocket surrounded by silicon dioxide. A pair of Schottky diodes and a resistor are formed outside the epitaxial pocket on the silicon dioxide and connected to the pocket by doped polycrystalline silicon.

Abstract: A microprocessor comprising: an address data path; an arithmetic logic unit data path, said data paths being capable of simultaneous operation; an information bus; a shared bus register; a shared input multiplexing apparatus for selectively transferring address and data information from said information bus and data information from said arithmetic logic unit data path to said shared bus register; and a multiplexing apparatus for transferring information from said shared bus register to said arithmetic logic unit data path and to said information bus via said address data path whereby said shared bus register is selectively useable as a memory data register, a memory address register and a temporary or "scratch-pad" register during normal operation of the microprocessor; and further comprising; a programmable logic array containing a sequence of microinstructions and apparatus connected thereto for testing the operability of the microprocessor.

Abstract: A method of removing bulk impurities from a semiconductor wafer is described comprising the steps of lapping the front and back surfaces of the wafer to remove 35 to 40 microns of material therefrom and to make the surfaces parallel, heating the wafer at a predetermined temperature preferably equal to or above the highest temperature to be used in subsequent device fabrication, etching the front and back surfaces of the wafer to remove 35 to 40 microns of material therefrom and thereafter polishing the front surface of the wafer for removing 20 microns of material therefrom. By means of the above process the number of surface defects caused by strain producing centers in the crystal lattice of the wafer is reduced from 500,000 defects per square centimeter to less than 1,000 defects per square centimeter.

Abstract: Diagnostic testing of a charge coupled device is facilitated by interconnecting the reference node of the sense amplifier for each data block in the CCD device with a probe contact on the device, thereby eliminating the need for applying a microprobe to the sensitive reference node. Reference voltages under different operating conditions can be evaluated by measuring the device generated reference voltage or by applying variable reference voltages through the probe contact to the reference node.

Abstract: An address gate for a random access memory includes a pair of emitter-coupled and collector-coupled transistors, and another transistor emitter-coupled to the pair of transistors. Complimentary outputs are read at the coupled emitters of the pair of transistors and the collector of the other transistor respectively, there being an input signal applied to the base of one of the pair of transistors, and a control signal applied to the base of the other of the pair of transistors, which overrides the operation of one of the pair of transistors when the control signal is in its high state.

Abstract: A process for fabricating an electrically erasable nonvolatile memory cell comprises forming a first region of insulating material which is less than about 200 Angstroms thick on a selected surface portion of an electrically-isolated relatively lightly doped pocket of epitaxial silicon of a first conductivity type such that first and second surface areas of the epitaxial pocket are exposed. Regions of the epitaxial pocket underlying the first and second exposed surface areas are doped such that first and second relatively lightly doped regions of a second conductivity type are formed in the epitaxial pocket. Relatively heavily doped polysilicon regions of the first conductivity type are formed on the first insulating region and on the second relatively lightly doped epitaxial region.

Abstract: A process and resulting structure are disclosed for forming vias in integrated circuit structures using metal silicide interconnections. A lower conductor is formed by sequentially depositing silicon and a refractory metal which reacts with the silicon to create a layer of metal silicide. A subsequent layer of silicon is deposited on the surface of the metal silicide. This layer of silicon is insulated from overlying layers by forming insulating material over desired regions of the layer of silicon. A second layer of metal is then deposited across the structure. In openings in the insulating material the metal reacts with the second layer of silicon to form a via of metal silicide. A final layer of silicon may be deposited to convert any remaining metal in the second layer of metal to metal silicide, and the structure annealed to lower its resistivity.

Abstract: An interruptible microprogram sequencing unit (MSU) for providing a sequence of microinstruction addresses to a control memory containing microinstructions for the operation of a microprogrammed apparatus. The MSU includes an address output for providing microinstruction addresses to the control memory, an address bus connected to the address output such that a plurality of microinstruction addresses applied to the address bus are sequentially provided to the address output, means connected to the address bus for applying the plurality of microinstruction addresses to the address bus, an interrupt return register operably connected to the address bus for receiving a microinstruction address from the address bus and storing the received microinstruction address, and means connected to the address bus for interrupting the sequence of microinstruction addresses and effecting storage of a microinstruction address on the address bus in the interrupt return register.

Abstract: Apparatus for amplifying output signals from a charge coupled area imaging device includes a resettable first floating gate amplifier connected to sense charge in the charge coupled device output register at a first location, a second floating gate amplifier connected to sense charge in the charge coupled device output register at a second location, and a charge limiting well disposed between the first location and the second location to remove charge in excess of a desired amount before the output signals are sensed at the second location. The dual preamplifiers permit optimization of the output signals from the charge coupled imaging device for two substantially different light levels by providing a substantially lower noise equivalent input signal level from the second preamplifier.

Abstract: A microprocessor integrated circuit design has improved partitioning between integrated injection logic (I.sup.2 L) and transistor-transistor logic (T.sup.2 L) in the integrated circuit. An information bus structure incorporating a bidirectional input and output buffer and a bidirectional input and output multiplexer minimizes the number of internal bus lines in the integrated circuit. An improved T.sup.2 - I.sup.2 L interface circuit and structure supplies a T.sup.2 L input to a plurality of I.sup.2 L input stages, each having a restricted cross-sectional area resistor element in the base of an I.sup.2 L input transistor. A storage register in the integrated circuit has a multiplexer portion provided at each flip-flop circuit of the register. A high speed feed forward flip-flop circuit is employed in registers of the integrated circuit where speed is critical. An improved voltage regulator and current source combination in a programmable logic array (PLA) reduces PLA temperature sensitivity. A pair of I.sup.

Abstract: A microprocessor for facilitating the execution of instructions which require repetitive shift and arithmetic logic unit operations comprises an arithmetic logic unit having a first and a second input and an output, a plurality of registers, at least one of which is a bidirectionally shifting register and multiplexing apparatus for selectively coupling each of said plurality of registers to said first and said second inputs and said output of said arithmetic logic unit.

Abstract: Circuitry for presetting a bipolar random access memory includes switching transistors, responsive to an applied memory preset signal, for opening the circuit between the memory word lines and their respective current sources, for applying a positive voltage to the bottom word lines, for breaking the circuitry between bit line clamping circuits and their respective power sources, and for grounding the bit line pairs to drain all current from the bit line circuits. The preset circuitry also includes read/write control transistors coupled between each bit line and a V.sub.cc source for steering the set of the memory cells upon removal of the preset signal.

Abstract: A discharge circuit for rapidly discharging the word lines of random access memories to thereby prevent erroneous reading from or writing into the memory during periods when the word lines are in a mid-state transition between selected and deselected voltage levels. Each discharge circuit associated with the memory word lines includes a transistor that is conductive only when a full select voltage level is applied to the word line and which controls conduction of a second multi-collector transistor coupled between top and bottom lines of a word line pair and a current source to discharge the word line pair during the mid-state transition period and to thus increase the speed capabilities of the memory.