Abstract: The n-channel VDMOS transistor is formed in an n-type active region of an integrated circuit with junction isolation. To prevent over-voltages between source and gate which could damage or destroy the gate dielectric, a p-channel MOS transistor is formed in the same active region and has its gate electrode connected to the gate electrode of the VDMOS transistor, its source region in common with the source region of the VDMOS transistor, and its drain region connected to the p-type junction-isolation region. The p-channel MOS transistor has a threshold voltage below the breakdown voltage of the gate dielectric of the VDMOS transistor so that it acts as a voltage limiter.
Abstract: An external heat sink is soldered to an internal heat sink incorporated into the bottom of a molded body of encapsulating resin for a package of an integrated power device. The power device is for surface mounting on a printed circuit board. The internal heat sink has at least a portion protruding from an outer surface of at least one face of the molded body. An external heat sink is mounted on the printed circuit board. The external heat sink has at least a surface abutting with a surface of the body, thus defining a separation gap between at least a surface of the protruding portion of the internal heat sink and an opposing surface of the external heat sink. This separation gap is filled with molten solder alloy during a normal soldering treatment of the printed circuit board.
Type:
Grant
Filed:
December 15, 1998
Date of Patent:
February 27, 2001
Assignee:
STMicroelectronics S.r.L.
Inventors:
Roberto Tiziani, Roberto Rossi, Claudio Maria Villa
Abstract: A radiation hardened memory device having static random access memory cells includes active gate isolation structures placed in series with oxide isolation regions between the active regions of a memory cell array. The active gate isolation structure includes a gate oxide and polycrystalline silicon gate layer electrically coupled to a supply terminal resulting in an active gate isolation structure that prevents a conductive channel extending from adjacent active regions from forming. The gate oxide of the active gate isolation structures is relatively thin compared to the conventional oxide isolation regions and thus, will be less susceptible to any adverse influence from trapped charges caused by radiation exposure.
Abstract: A current mirror has an input node for receiving an input current and an output node for providing an output current. First, second and third transistors are provided with each transistor having first and second current path terminals and a control terminal. The control terminals of the first and second transistors are connected to each other. The first current path terminal of the first transistor and one of the current path terminals of the second transistor are connected to a power supply. The control terminal of the third transistor is connected to the input node. One of the first and second current path terminals of the third transistor are connected to the output node and the other of the first and second current path terminals of the third transistor are connected to the other of the first and second current path terminals of the second transistor. A resistive element is arranged between the input node and the second current path terminal of the first transistor.
Abstract: A Flash EEPROM includes a negative voltage generator for generating a negative voltage to be supplied to control gate electrodes of memory cells for erasing the memory cells. The Flash EEPROM also has a first positive voltage generator for generating a first positive voltage, independent from an external power supply of the Flash EEPROM, to be supplied to source regions of the memory cells during erasing.
Type:
Grant
Filed:
July 24, 1996
Date of Patent:
February 27, 2001
Assignee:
STMicroelectronics S.r.l.
Inventors:
Marco Dallabora, Corrado Villa, Luigi Bettini
Abstract: Process for manufacturing an electrically programmable non-volatile memory device having electrically programmable non-volatile memory cells comprising floating-gate MOS transistors, a first kind of MOSFETs, and a second kind of MOSFETs capable of substaining gate voltages higher than that sustainable by the MOSFETs of the first kind. The process includes forming a first gate oxide layer for the floating-gate MOS transistors, a second gate oxide layer for the MOSFETs of the first kind, and a third gate oxide layer for the MOSFETs of the second kind. The first gate oxide layer further comprises a tunnel oxide region.
Type:
Grant
Filed:
August 6, 1998
Date of Patent:
February 27, 2001
Assignee:
STMicroelectronics, S.r.l.
Inventors:
Roberta Bottini, Giovanna Dalla Libera, Bruno Vajana, Carlo Cremonesi
Abstract: For each memory cell to be programmed, the present threshold value of the cell is determined; the desired threshold value is acquired; the analog distance between the present threshold value and the desired threshold value is calculated; and a programming pulse is then generated, the duration of which is proportional to the analog distance calculated. The programming and reading cycle is repeated until the desired threshold is reached. By this means a time saving is obtained, owing to the reduction of the number of intermediate reading steps. The method permits programming in parallel and simultaneously of a plurality of cells of a memory array which is connected to a single word line and to different bit lines, each with a programming pulse the duration of which is proportional to the analog distance calculated for the same cell. The programming process is thus very fast, owing to parallel application of the programming and the saving in the intermediate reading cycles.
Type:
Grant
Filed:
May 11, 1998
Date of Patent:
February 27, 2001
Assignee:
STMicroelectronics S.r.l.
Inventors:
Pier Luigi Rolandi, Roberto Canegallo, Ernestina Chioffi, Danilo Gerna, Marco Pasotti
Abstract: A method of avoiding disturbance during the step of programming and erasing an electrically programmable, semiconductor integrated non-volatile memory device which includes a matrix of memory cells divided into sectors and programmable in a byte mode is disclosed. An operation of verification of the contents of the byte to be programmed, to be carried out for each individual bit, is provided even before the first program pulse is applied. The method also provides for the parallel erasing of several sectors during an erase step, and a verification of the erase step for each sector in the matrix. If the verification shows that a sector has been erased, the sector is applied no further erase pulses.
Type:
Grant
Filed:
September 27, 1999
Date of Patent:
February 27, 2001
Assignee:
STMicroelectronics S.r.l.
Inventors:
Marco Dallabora, Corrado Villa, Simone Bartoli, Marco Defendi
Abstract: A method and an apparatus are provided for communicating data in noisy environments. A method preferably includes communicating a first fixed data signal at a first frequency on a first data communications line and communicating a second data signal at a second frequency on a second data communications line. The second frequency is preferably correlated to the first frequency by a predetermined coefficient so as to define a correlation value between the first and second data signals. The correlation value preferably represents a predetermined function. The method also preferably includes determining the correlation value responsive to the first and second data signals. The method can also advantageously include communicating a third data signal at the second frequency on the second data communications line. The third data signal is preferably phase shifted from the second data signal.
Abstract: A read device comprises a sense amplifier having an input connected to a data memory cell to be read and an output issuing a signal correlated to the threshold voltage of the data memory cell. A first and second voltage sources circuit have respect first and second outputs that supply respective first and a second input reference voltage. A resistive divider connected between the first and the second outputs of the voltage source circuits has a plurality of outputs supplying respective intermediate reference voltages having values between the first and the second input reference voltages. A plurality of comparator circuits have a first input connected to the output of the sense amplifier, a second input connected to a respective output of the resistive divider, and an output supplying a digital signal indicative of the outcome of a respective comparison.
Type:
Grant
Filed:
October 22, 1999
Date of Patent:
February 27, 2001
Assignee:
STMicroelectronics, S.r.l.
Inventors:
Marco Pasotti, Roberto Canegallo, Giovanni Guaitini, Pier Luigi Rolandi
Abstract: A circuit and method for reading a non-volatile memory include providing a first random memory reading cycle and performing, at the end of the random reading cycle, a collective page precharge. Then, performing a reading cycle of the page or random type, depending on whether the subsequent reading must be performed within the same page or not. Then, if a page reading cycle is performed, executing, when the data item is captured, a page precharge step in preparation for both page reading and random reading.
Abstract: A circuit and method are disclosed for controlling the slew rate of the output voltage of a driver in a push-pull configuration. The circuit includes a capacitive element and a current generator circuit for generating one or more currents. The circuit further includes a switching circuit for selectively charging and discharging the capacitive element in response to an input signal, wherein the voltage across the capacitive element is a voltage signal whose edge transitions have slopes which are controlled based upon the capacitance of the capacitive element and the current level of the one or more currents. The circuit further includes a conversion circuit for converting the voltage signal into one or more current signals, the one or more current signals being used to control a pull-up device and pull-down device of the driver so that the slopes of the edge transitions of the output voltage thereof is based upon the slopes of the edge transitions of the voltage signal appearing across the capacitive element.
Abstract: A method, and related circuit, prevent the triggering of a parasitic transistor in an output stage of an electronic circuit. The stage includes a transistor pair with at least one transistor of the pull-up PMOS type having respective source, gate and drain terminals and a body terminal, and a parasitic bipolar transistor having a terminal connected to the body terminal. The method includes the steps of providing a capacitor connected between the body and source terminals of the PMOS transistor; and using a control circuit to suppress the body effect of the pull-up PMOS transistor.
Abstract: A method for fabricating an integrated circuit transistor begins with doping the substrate in the device active areas after field oxide regions have been formed. This dopant helps to reduce short channel transistor effects. A thin layer of epitaxial silicon is then grown over the substrate active regions. A field effect transistor is formed in the epitaxial layer and underlying substrate. The transistor channel region is in the relatively lightly doped epitaxial layer, but the underlying doped substrate layer helps minimize short channel effects.
Abstract: A method is provided for forming planar multilevel metallization of a semiconductor integrated circuit, and an integrated circuit formed according to the same. Multilevel metallization is achieved through a planar process at each layer to allow for minimum widths of lines and vias and minimal lateral spacing between lines. Conductive lines and contacts are formed before planarization to further achieve good step coverage. A first metallization layer is formed by depositing aluminum over the integrated circuit, patterning and etching to form metal interconnect lines. Regions of planar insulating material are then formed between the metal lines. Another layer of aluminum is deposited and etched to form metal vias over selected portions of the metal lines. This layer of aluminum is patterned with a reverse pattern of that used to pattern the metal lines. Again, regions of planar insulating material are formed between the metal vias.
Type:
Grant
Filed:
July 28, 1995
Date of Patent:
February 20, 2001
Assignee:
STMicroelectronics, Inc.
Inventors:
Kuei-Wu Huang, Tsiu C. Chan, Jamin Ling
Abstract: A capacitance sensor detects the absence/presence of physical matter on a sensing surface of the sensor. The capacitive sensor is a multi-cell sensor wherein each cell has one or more buried, protected, and physically inaccessible capacitor plates. The sensor is physically placed in an environment that is to be monitored for deposition of a particle, vapor, and/or drop of a foreign material on the sensing surface. All cells are initially placed in a startup condition or state. Thereafter, the cells are interrogated or readout, looking for a change in the equivalent feedback capacitance that results from an electrical field shape modification that is caused by the presence of physical matter on the sensing surface. When no such change is detected, the method is repeated for another cell. When a change is detected for a cell, a particle/vapor/drop output is provided.
Abstract: Methods of forming, in an integrated circuit, aluminum-silicon contacts with a barrier layer is disclosed. The barrier layer is enhanced by the provision of titanium oxynitride layers adjacent the silicide film formed at the exposed silicon at the bottom of the contact. The titanium oxynitride may be formed by depositing a low density titanium nitride film over a titanium metal layer that is in contact with the silicon in the contact; subsequent exposure to air allows a relatively large amount of oxygen and nitrogen to enter the titanium nitride. A rapid thermal anneal (RTA) both causes silicidation at the contact location and also results in the oxygen and nitrogen being gettered to what was previously the titanium/titanium nitride interface, where the oxygen and nitrogen react with the titanium metal and nitrogen in the atmosphere to form titanium oxynitride. The low density titanium nitride also densifies during the RTA.
Abstract: In an integrated circuit comprising a so-called “switched” capacitor, the latter is switched by a parallel circuit of two complementary switching transistors having mutually complementary switching pulse trains. Due to parasitic effects during this switching operation, disturbing offset voltages arise at the switched capacitor. In order to avoid such offset voltages, the edges of the one switching pulse train are shifted in time with respect to the corresponding edges of the complementary switching pulse train. To this end, a switching pulse generator contains a delay member fed with a control signal which is formed by means of a constant reference voltage using a dummy or simulation of that circuit that contains the switched capacitor.
Type:
Grant
Filed:
December 1, 1998
Date of Patent:
February 20, 2001
Assignee:
STMicroelectronics, S.r.l.
Inventors:
Jörg Schambacher, Peter Kirchlechner, Jürgen Lübbe
Abstract: Disclosed is a CMOS image sensor that includes pixels employing a radiation-sensitive resistive element in which the resistance of the element changes in response to the quantity of radiation striking it. The resistive elements are made from an appropriately doped polycrystalline semiconductor material such as polysilicon. The pixels are provided on a semiconductor device in which the photosensitive resistive elements are provided on a first layer and the pixel associated transistors are provided on a second layer. The fill factor may be approach 100 percent for such pixels.
Type:
Grant
Filed:
June 24, 1998
Date of Patent:
February 13, 2001
Assignee:
STMicroelectronics, Inc.
Inventors:
Alexander Kalnitsky, Frank Randolph Bryant, Marco Sabatini
Abstract: A high impedance load for an integrated circuit device provides an undoped, or lightly doped, layer of epitaxial silicon. The epitaxial silicon layer is formed over a conductive region in a substrate, such as a source/drain region. A highly conductive contact, such as a refractory metal silicide interconnect layer, is formed on top of the epitaxial silicon layer. Preferably, the epitaxial silicon layer is formed using solid phase epitaxy, from excess silicon in the silicide layer, by annealing the device after the silicide layer has been deposited.