Patents Represented by Attorney David J. Paul
  • Patent number: 5321648
    Abstract: A stacked v-cell (SVC) capacitor using a modified stacked capacitor storage cell fabrication process. The SVC capacitor is made up of polysilicon structure, having a v-shaped cross-section, located at a buried contact and extending to an adjacent storage node overlaid by polysilicon with a dielectric sandwiched in between. The addition of the polysilicon structure increases storage capability 70% without enlarging the surface area defined for a normal stacked capacitor cell.
    Type: Grant
    Filed: April 15, 1993
    Date of Patent: June 14, 1994
    Assignee: Micron Technology, Inc.
    Inventors: Charles H. Dennison, Pierre C. Fazan, Ruojia Lee, Yauh-Ching liu
  • Patent number: 5304506
    Abstract: The present invention discloses an on chip decoupling capacitor structure having a first decoupling capacitor with one electrode formed in the conductively doped silicon substrate and a second electrode made of conductively doped polysilicon. The second electrode is a common electrode to a second decoupling capacitor overlying and thereby coupled in parallel to said first decoupling capacitor. The second capacitor's first electrode is the common electrode and its second electrode is made of conductively doped polysilicon. The electrodes made of the conductively doped polysilicon may be further enhanced by forming a silicided material, such as tungsten silicide, thereon. The decoupling capacitors' dielectric can be formed from high dielectric constant materials, such as TEOS, oxide, nitride or any combination thereof.
    Type: Grant
    Filed: March 10, 1993
    Date of Patent: April 19, 1994
    Assignee: Micron Semiconductor, Inc.
    Inventors: Stephen R. Porter, Navjot Chhabra
  • Patent number: 5300875
    Abstract: A concept of passively recharging the battery of battery backed electronic circuits and in particular utilizing these methods to recharge an RFID transponder's secondary cell(s). The invention particularly relates to battery backed transponders which contain rechargeable batteries wherein the recharging circuitry of the present invention allows for passive (non-contact) recharging of a battery residing in a transponder unit that may or may not be directly accessible for handling. The passive recharging strategies disclosed include utilizing energy sources such as: 1) a radio frequency (rf) signal generated outside the package; 2) a seismic geophone; 3) seismic piezoelectric accelerometers; 4) photovoltaic cells located outside of the transponder package; 5) infrared p-v cells located inside of the package driven by the heated package; and/or 5) acoustic energy (sonic and ultrasonic) coupled to the recharging circuitry via an acoustic transducer.
    Type: Grant
    Filed: June 8, 1992
    Date of Patent: April 5, 1994
    Assignee: Micron Technology, Inc.
    Inventor: John R. Tuttle
  • Patent number: 5286993
    Abstract: The present invention provides a programmable structure for a programmable read-only memory (PROM) which utilizes one-sided ozone spacers constructed on the digit lines as one time programmable nodes. An oxide/nitride/oxide layer (ONO) is used as an interface between underlying parallel rows of digit lines, having one-sided ozone spacers, and overlying parallel columns of word lines in a programmable read only memory With a each digit line passing under each word line in a row/column matrix is formed thereby providing a programmable digit/word line matrix. Each crossing point of the digit and word lines in the matrix will be permanently programmed to either a one or a zero by rupturing the thin ONO dielectric interface by applying the appropriate voltage potential between the associated digit/word line conductors.
    Type: Grant
    Filed: March 23, 1992
    Date of Patent: February 15, 1994
    Assignee: Micron Technology, Inc.
    Inventors: Tyler A. Lowrey, Ruojia Lee
  • Patent number: 5283204
    Abstract: The invention is directed to maximizing storage cell surface area in a high density/high volume DRAM (dynamic random access memory) fabrication process. Fabrication methods are disclosed that, when used with existing capacitor fabrication processes, will reduce cell leakage and allow for increased capacitance. The present invention corrects any severed storage node poly that may have resulted from a misalignment of a masking pattern used for defining future buried contacts by placing passivation oxidation over the existing wafer surface which, in effect, seals off the severed storage node poly form the capacitor's top cell plate poly. The passivation oxidation prevents cell plate to plate leakage while protecting the severed storage node poly from subsequent deposition of conductive layers.
    Type: Grant
    Filed: April 15, 1992
    Date of Patent: February 1, 1994
    Assignee: Micron Semiconductor, Inc.
    Inventors: Howard E. Rhodes, Tyler A. Lowrey
  • Patent number: 5281549
    Abstract: An existing stacked capacitor fabrication process is modified to construct a three-dimensional stacked capacitor, referred to as a Stacked I-Cell (SIC). The SIC design defines a capacitor storage cell that in the present invention is used in a DRAM process. The SIC is made up of a polysilicon storage node structure having a I-shaped cross-sectional upper portion with a lower portion extending downward and making contact to an active area via a buried contact. The polysilicon storage node structure is overlaid by polysilicon with a dielectric sandwiched in between to form a completed SIC capacitor. The novel 3-dimensional shaped polysilicon storage node plate having an adjustable I-shaped cross-section, allows substantial capacitor plate surface area of 200% or more to be gained at the storage node over that of a conventional STC.
    Type: Grant
    Filed: December 4, 1992
    Date of Patent: January 25, 1994
    Assignee: Micron Technology, Inc.
    Inventors: Pierre Fazan, Hiang C. Chan
  • Patent number: 5278460
    Abstract: The CMOS voltage compensating input buffer circuit of the present invention provides a means to stabilize input level trip points and is comprised of a voltage compensating circuit having an input node and an output drive node coupled to an input buffer. The voltage compensating circuit receives its input from a voltage adjusting circuit that follows changes in V.sub.CC while its output drive node is coupled to the series connected CMOS input buffer circuit having an input node and an output node. The buffer's input node receives a signal that VIH/VIL trip points will determine if the output is to be a high or a low and the buffer's output node then couples the resultant level to an output buffer circuit comprised of a CMOS inverter which provides the final output drive. The present invention provides trip point levels corresponding to industry standard VIH/VIL levels to accurately determine the corresponding output with operating voltage supplies (regulated or unregulated) operating between 2 V to 7.5 V.
    Type: Grant
    Filed: April 7, 1992
    Date of Patent: January 11, 1994
    Assignee: Micron Technology, Inc.
    Inventor: Stephen L. Casper
  • Patent number: 5278091
    Abstract: The present invention develops a container capacitor by forming a first insulative layer over conductive word lines; forming an opening between neighboring conductive word lines; forming a conductive plug between neighboring parallel conductive word lines; forming a planarized blanketing second insulating layer over the first insulative layer and the conductive plug; forming an opening into the second insulating layer, the opening thereby forming a container shape; forming a conductive spacer adjacent the wall of the container form, the conductive spacer having inner and outer surfaces; removing the second insulating layer, thereby exposing the outer surface of the conductive spacer; forming a layer of hemispherical grained conductive material superjacent the inner and outer surfaces of the conductive spacer; forming insulating spacers adjacent the inner and outer surfaces of the hemispherical grained conductive material; patterning the hemispherical grained conductive material to form a separate conductive c
    Type: Grant
    Filed: May 4, 1993
    Date of Patent: January 11, 1994
    Assignee: Micron Semiconductor, Inc.
    Inventors: Pierre Fazan, Viju Mathews
  • Patent number: 5275965
    Abstract: The invention is directed to improving trench isolation between active devices by using gated sidewalls. In a first embodiment, trenches are etched into the substrate and a thin oxide film is formed to passivate the trench sidewalls and serve as a sidewall gate oxide. The oxide is removed from the bottom of the trench while leaving the sidewall oxide intact. A thin poly layer is formed into the trench so that the thin poly does not completely fill the trench, yet the thin poly film will overlie the oxide sidewalls and make contact to the exposed substrate at the bottom of the trench. The trench is then completely filled with a conformal oxide that is planarized. The planarized oxide is etched during thermal oxide etch and a sacrificial oxide is grown. Following threshold adjust implants, the sacrificial oxide is removed and the final gate sidewall oxide is formed.
    Type: Grant
    Filed: November 25, 1992
    Date of Patent: January 4, 1994
    Assignee: Micron Semiconductor, Inc.
    Inventor: Monte Manning
  • Patent number: 5271798
    Abstract: The present invention remedies the problems associated with selective etching of material, and in particular tungsten, by locally removing the material (e.g. tungsten) from the alignment marks through wet etching without the need for any photo steps. Either before or after chemical mechanical polishing, the wafers are flatly aligned and a tungsten etching agent is introduced through an etchant dispensing apparatus onto the alignment marks. Since an alignment mark is normally a few hundred microns in size and there is a large unused silicon real estate around the alignment marks, the alignment constraints vis-a-vis etchant dispensing apparatus and wafer are not very critical and tungsten plugs in the live dice are easily protected from the wet etch. After the etch, the etching byproduct is removed by suction and the wafer is cleaned by being rinsed in distilled water.
    Type: Grant
    Filed: March 29, 1993
    Date of Patent: December 21, 1993
    Assignee: Micron Technology, Inc.
    Inventors: Gurtej S. Sandhu, Alan E. Laulusa
  • Patent number: 5270241
    Abstract: An existing stacked capacitor fabrication process is modified to construct a three-dimensional stacked container capacitor. The present invention develops the container capacitor by etching an opening (or contact opening) into a low etch rate oxide. The contact opening is used as a form for deposited polysilicon that conforms to the sides of the opening walls. Within the thin poly lining of the oxide container a high etch-rate oxide, such as ozone TEOS, is deposited over the entire structure thereby bridging across the top of the oxide container. The high etch-rate oxide is planarized back to the thin poly and the resulting exposed poly is then removed to separate neighboring containers. The two oxides, having different etch rates, are then etched thereby leaving a free-standing poly container cell with 100% (or all) of the higher etch rate oxide removed and a pre-determined oxide surrounding the container still intact.
    Type: Grant
    Filed: November 6, 1992
    Date of Patent: December 14, 1993
    Assignee: Micron Technology, Inc.
    Inventors: Charles H. Dennison, Michael A. Walker
  • Patent number: 5266523
    Abstract: Self-aligned contacts are formed between a first layer of material which can be oxidized, such as polycrystalline silicon (poly 1), and a second layer of material such as metal or polycrystalline silicon (poly 2). A patterned layer of material, such as nitride, that prevents the first layer from oxidizing is deposited over the poly 1 layer. The exposed poly 1 material is oxidized, while the poly 1 material covered by the nitride is protected from oxidization. The nitride is removed and another layer of conductive material is formed, and thus contacts the poly 1 layer which was protected from oxidation, while the oxide insulates the other poly 1 areas.
    Type: Grant
    Filed: March 12, 1993
    Date of Patent: November 30, 1993
    Assignee: Micron Technology, Inc.
    Inventor: Monte Manning
  • Patent number: 5266513
    Abstract: A stacked multi fingered cell (SMFC) capacitor using a modified stacked capacitor storage cell fabrication process. The SMFC is made up of polysilicon structure, having a multi-fingered cross-section, located at a buried contact and extending to an adjacent storage node overlaid by polysilicon with a dielectric sandwiched in between. The addition of the polysilicon structure increases storage capability 120% without enlarging the surface area defined for a normal stacked capacitor cell.
    Type: Grant
    Filed: November 19, 1992
    Date of Patent: November 30, 1993
    Assignee: Micron Technology, Inc.
    Inventors: Pierre C. Fazan, Charles H. Dennison, Ruojia Lee, Yauh-Ching Liu
  • Patent number: 5262343
    Abstract: This invention relates to semiconductor circuit memory storage devices and more particularly to a process to develop three-dimensional stacked capacitor cells using a high dielectric constant material as a storage cell dielectric and a combination of conductively doped polysilicon and metal silicide as the capacitor plates of a storage cell for use in high-density dynamic random access memory (DRAM) arrays. The present invention teaches how to fabricate three-dimensional stacked capacitors by modifying an existing stacked capacitor fabrication process to construct the three-dimensional stacked capacitor cell incorporating a high dielectric constant material as the cell dielectric that will allow denser storage cell fabrication with minimal increases of overall memory array dimensions. A capacitance gain of 3 to 10.times. or more over that of a conventional 3-dimensional storage cell is gained by using a high dielectric constant material as the storage cell dielectric.
    Type: Grant
    Filed: March 6, 1992
    Date of Patent: November 16, 1993
    Assignee: Micron Technology, Inc.
    Inventors: Howard E. Rhodes, Pierre Fazan, Hiang C. Chan, Charles H. Dennison, Yauh-Ching Liu
  • Patent number: 5258096
    Abstract: The present invention introduces the use of "local" etch stop layers having highly selective etch characteristics vis-a-vis insulating layers into which the contact/vias are etched. Any kind of conducting material which possesses etch selectivity to an insulator such as oxide (i.e. doped polysilicon, tungsten, tungsten silicide, titanium, titanium silicide, titanium nitride and the like) may be used and the process flow described herein uses conductively doped polysilicon as an example to accomplish this task without the need to add any extra photo or mask step to a conventional dynamic random access memory (DRAM) process flow and with the addition of a minimal number of deposition and etch steps. During a first masking step to open a contact, a subsequent etch opens up the P-channel gate area to thin down the underlying oxide. Polysilicon is then deposited which is followed by formation of an oxide.
    Type: Grant
    Filed: August 20, 1992
    Date of Patent: November 2, 1993
    Assignee: Micron Semiconductor, Inc.
    Inventors: Gurtej S. Sandhu, Donwon Park, Tyler A. Lowrey
  • Patent number: 5257222
    Abstract: The present invention comprises a method to program antifuse elements in integrated circuits, such as programmable read-only memory (PROM) or option selections/redundancy repair on dynamic random access memories (DRAMs) by utilizing the phenomenon of transistor snap-back. Multiple programming pulses are applied to an NMOS transistor which provides access to the desired antifuse element. The first pulses applied ruptures the antifuse element causing it so become a resistive short. The second programming pulses cause the access NMOS transistor to go into snap-back thus allowing a surge of current to flow through the resistively shorted antifuse thereby lowering the resistance of the shorted antifuse element substantially allowing for less power consumption and higher reliability of the permanently programmed element.
    Type: Grant
    Filed: January 14, 1992
    Date of Patent: October 26, 1993
    Assignee: Micron Technology, Inc.
    Inventor: Roger R. Lee
  • Patent number: 5257225
    Abstract: The present invention comprises a method to program programmable structures in integrated circuits, such as programmable read-only memory (PROM), erasable programmable read-only memory family (EPROMS, EEPROMS, etc.) or option selections/redundancy repair on dynamic random access memories (DRAMs) by utilizing multiple programming pulses that vary in pulse width and amplitude. Multiple programming pulses (or a pulse train) of the present invention are applied to the desired structure to be programmed, whether that structure be a fuse in a bipolar PROM, an antifuse element in a CMOS PROM, an option selecting element (fuse or antifuse) in a DRAM, the programmable gates of the EPROM family (EEPROMs, Flash EEPROMS, etc.). The pulse train applied to the programmable structure may be as few as one pulse, having sufficient amplitude and pulse width, or the pulse train may be a plurality of pulses varying in pulse amplitude or pulse width.
    Type: Grant
    Filed: March 12, 1992
    Date of Patent: October 26, 1993
    Assignee: Micron Technology, Inc.
    Inventor: Roger R. Lee
  • Patent number: 5252517
    Abstract: The method of the present invention introduces a fabrication method for providing capacitor cell polysilicon isolation from a polysilicon contact plug in a semiconductor fabrication process, by providing a contact opening through a first insulating layer, the cell polysilicon layer, and a second insulating layer, thereby exposing patterned edges of the cell polysilicon and providing access to an underlying diffusion area. The contact opening is then filled with a conductively doped polysilicon and an upper portion the polysilicon filler is removed until its top surface is recessed below the bottom surface of the cell polysilicon. Next, the cell polysilicon's patterned edges and the top of the first conductive material are oxidized which is followed by an anisotropic etch to remove the oxide only from the top of the polysilicon filler while retaining a major portion of the oxide on the cell polysilicon's patterned edges. Finally, the contact opening is refilled with conductively doped polysilicon.
    Type: Grant
    Filed: December 10, 1992
    Date of Patent: October 12, 1993
    Assignee: Micron Semiconductor, Inc.
    Inventors: Guy T. Blalock, David S. Becker
  • Patent number: 5250459
    Abstract: The present invention introduces a process to fabricate very low resistive antifuse elements by introducing Antimony (Sb) into one or both of the antifuse element's electrodes and thereby resulting in said very low resistive (programmed) antifuse element. Introducing Sb into the antifuse electrode(s) reduces the depletion width of the dopant impurities thereby causing a large concentration of n+ dopants in the antifuse electrode(s). This allows a reduction in the voltage required across the electrodes to breakdown the inner lying dielectric and thus program or short the electrodes together. In addition, once the two electrodes become shorted together to form a filament, the Sb will flow form one or both electrode(s) and thereby heavily dope the filament itself with n+ atoms. With the presence of the heavy concentration of n+ atoms in the filament, the shorted antifuse element is reduced in resistance by as much as a few hundred ohms or below when compared to antifuse elements fabricated by other methods.
    Type: Grant
    Filed: April 14, 1992
    Date of Patent: October 5, 1993
    Assignee: Micron Technology, Inc.
    Inventor: Roger R. Lee
  • Patent number: 5246876
    Abstract: A low cost active P-channel load for use in semiconductor devices is developed. The active P-channel load may be used in a variety of designs, such as functioning as a pullup device in integrated circuits and more specifically for use as a pullup resistor in SRAM devices. The P-channel load is built overlying an active NMOS device and not only takes up less die space but also allows for a simple process to construct the P-channel load. This P-channel device is easily incorporated into an SRAM process flow to build an SRAM cell made up of active NMOS devices that utilize the P-channel devices as pullups.
    Type: Grant
    Filed: January 22, 1993
    Date of Patent: September 21, 1993
    Assignee: Micron Technology, Inc.
    Inventor: Monte Manning