192
New Patents
4408386 METHOD OF MANUFACTURING SEMICONDUCTOR INTEGRATED CIRCUIT DEVICES Tetsuya Takayashiki, Taij Usui, Tetsuma Sakurai, Tokyo, Japan assigned to Oki Electric Industry Co Ltd; Nippon Telegraph and Telephone Public Corporati Spaced recesses are formed in a surface of a low impurity concentration P type single-crystal substrate by using a mask. A P type impurity is diffused at a high concentration into an entire surface of the substrate including the recesses to form a P type diffused layer, and an N type layer is epitaxially grown on the P type diffused layer. Then, mask layers are formed on bottom surfaces of the recesses in the epitaxially grown N type layer and this N type layer is anisotropically etched by using the mask layers to form island regions in the recesses. After removing the mask layers, N type diffused layers are formed to cover the island regions. An insulating film (SiO2) acting to isolate completed transistor elements is formed on the P and N type diffused layers, and a polycrystalline silicon layer acting as a support of a dielectrically isolated integrated circuit device is formed on the insulating film. Then, the rear surface of the single-crystal silicon substrate is ground off to expose the insulating film. MOS or bipolar type transistor elements are formed in the island regions to obtain a dielectrically isolated semiconductor integrated device.
4408385 SEMICONDUCTOR INTEGRATED CIRCUIT WITH IMPLANTED RESISTOR ELEMENT IN POLYCRYSTALLINE SILICON LAYER Rao G R Mohan, John S Stanczak, Jih-chan Lien, Shyam Bhatia assigned to Texas Instruments Incorporated
gate for an MOS transistor and as an interconnection overlying field oxide. Resistors of this type are ideally suited for load devices in static RAM cells.
4408304 SEMICONDUCTOR MEMORY Jun-ichi Nishizawa, Ohmi Tadahiro, Takashige Tamamushi, Sendai, Japan assigned to Semiconductor Research Foundation i
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A semiconductor memory is provided with a hook structure composed of first to fourth regions and is capable of non-destructive readout. The third and fourth regions of the hook structure are both made floating and each form one of main electrode regions of each of a write and/or refresh transistor and a readout transistor. Carriers which are injected from the other main electrode region of the write transistor are stored as excess majority carriers in the third region and majority carriers of the fourth region flow out therefrom into the first region via the third and second regions, in consequence of which the fourth region lacks in the majority carrier and voltages of the floating third and fourth regions vary. The voltage variation of the fourth region is read out by the readout transistor. The excess majority carriers stored in the third region flow out therefrom into the other main electrode region of the write transistor and become extinct when it operates as a refresh transistor.
4404662 METHOD AND CIRCUIT FOR ACCESSING AN INTEGRATED SEMICONDUCTOR MEMORY Charles Masenas assigned to International Business Machines Corporation
Resistor elements for MOS integrated circuits are made by an ion implant step compatible with a self-aligned N-channel silicon-gate process. The resistor elements are in a part of a polycrystalline silicon layer which is also used as a
A memory system is provided having an array of cells, each of which may include first and second cross-coupled inverting NPN transistors and first and second PNP transistors for injecting charge into the first and second inverting transistors. A first bit/sense line of a bit/sense line
New Patents
193
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SEMICONDUCTOR DEVICE SYSTEM Setsufumi Kamuro, Yoshifumi Masaki, Yamatokoriyama, Japan assigned to Sharp Kabushiki Kaisha
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pair is connected to the emitter of the first inverting transistor and a second bit/sense line of the pair is connected to the emitter of the second inverting transistor and a common word line is connected to the emitters of the first and second charge injecting transistors. To read a selected cell, all cells of the array are discharged through the word lines, the pair of bit/sense lines connected to the selected cell are electrically floated or isolated and the word line connected to the selected cell is energized by a word driver. The signal developed in the bit/sense lines connected to the selected cell is detected while the word line connected to the selected cell is being energized by the word driver.
4404657
4404048 SEMICONDUCTOR DEVICE MANUFACTURE
SEMICONDUCTOR MEMORY CIRCUIT Tohr Furuyama, Tetsuy Iizuka, Yokohama, Japan assigned to Tokyo Shibaura Denki Kabushiki Kaisha .~t_ .CL
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A ratioless semiconductor read only memory circuit comprises a plurality of insulated gate field-effect transistors being arranged in the form of a matrix consisting of columns and columns, bit lines of the rows of the transistors connected in parallel a sampling transistor connected in series to each of the rows of the transistors and each of the bit lines, and a row selection circuit connected to the respective bit lines for selecting one of the bit lines. The transistors of said array corresponding to individual bits are of the enhancement type or the depletion type depending on desired logic content.
Dirk A Vogelzang, Nijmegen, Netherlands assigned to U S Philips Corporation 5 ~ 2 1
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A semiconductor memory circuit includes a power supply terminal; a first MOS transistor; a second MOS transistor whose source, gate and drain are respectively connected to the source, drain and gate of the first MOS transistor; first and second resistors connected between the power supply terminal and the drains of the first and second MOS transistors; a data line; a word line; and a third MOS transistor whose current path is connected between the drain of the first MOS transistor and data line, and whose gate is connected to the word line. The semiconductor memory circuit further includes a write control line whose potential is set at a high level when a readout operation is effected. The sources of the first and second MOS transistors are jointly connected to the write control line.
P-type isolation regions, which surround an island of an n-type epitaxial layer, are formed by providing a p-type dopant at a part of the surface of a p-type silicon substrate. After growing the layer a p-type dopant is also provided at the surface of the layer opposite the part of the substrate surface where the dopant is provided. The dopants are diffused into the layer until the ptype regions meet. To inhibit diffusion of the ptype dopant during epitaxial growth, an n-type dopant having a lower diffusion coefficient than that of the p-type dopant is provided at the part of the substrate surface before providing the epitaxial layer. Formation of the isolation regions can be carried out simultaneously with the formation of p-type regions of a circuit element, for example a transistor, in the islands.