Additional Control Electrode Is Doped Region In Semiconductor Substrate Patents (Class 257/318)
  • Patent number: 6462372
    Abstract: A stack-gate structure including a masking dielectric layer over a control-gate layer over an intergate dielectric layer over a floating-gate layer formed on a gate-dielectric layer is formed on a semiconductor substrate having an active region isolated by field-oxides and is oxidized to form a first dielectric layer over the sidewalls of the control-gate layer, a second dielectric layer over the sidewalls of the floating-gate layer, and a thicker oxide layer over each side portion of the active region having a gradedoxide layer formed near two gate edges. An integrated source/drain landing island having a portion formed over a source/drain diffusion region for contact and an extended portion formed over a second dielectric layer and on a graded-oxide layer is acted as a field-emission cathode/anode. The scaled stack-gate flash memory device of the present invention can be programmed and erased through two-tunneling paths or one tunneling path without involving the channel region.
    Type: Grant
    Filed: October 9, 2001
    Date of Patent: October 8, 2002
    Assignee: Silicon-Based Technology Corp.
    Inventor: Ching-Yuan Wu
  • Patent number: 6459119
    Abstract: Systems and methods are described for providing an array of buried transistor cells with at least one contact array structure. A contact array structure for a buried type transistor array includes a first diffusion bit line coupled to the plurality of transistors; a first plurality of contacts coupled to the source diffusion bit line; and a first conductor coupled to the first plurality of contacts. The systems and methods provide advantages in that the diffusion line resistance is reduced, the read current and speed are reduced, and the voltage-time distribution is tightened when writing by hot electron programming.
    Type: Grant
    Filed: November 8, 1999
    Date of Patent: October 1, 2002
    Assignee: Macronix International Co., Ltd.
    Inventors: Chin-Yi Huang, Yun Chang
  • Patent number: 6448605
    Abstract: A method of fabricating a gate is described. A first dielectric layer having a first opening is formed on a substrate. A gate dielectric layer is formed in the opening. A lower portion of a floating gate is formed on the gate dielectric layer. A source/drain region is formed in the substrate beside the lower portion of the floating gate. A conductive layer is formed on the first dielectric layer to completely fill the first opening. The conductive layer is patterned to form a second opening in the conductive layer. The second opening is above the first opening and does not expose the first dielectric layer. The second opening has a tapered sidewall and a predetermined depth. A mask layer is formed to cover the conductive layer and fill the second opening. The mask layer outside the second opening is removed to expose the conductive layer. A portion of the mask layer is removed to leave a first etching mask layer in the second opening.
    Type: Grant
    Filed: August 8, 2001
    Date of Patent: September 10, 2002
    Assignee: Macronix International Co. Ltd.
    Inventor: Ching-Yu Chang
  • Patent number: 6448607
    Abstract: A flash memory cell with an embedded gate structure capable of storing two bits of information and the operation of such a flash memory cell are provided. A first ion-doped region, serving as a source terminal, is formed in a semiconductor substrate. An embedded gate structure and a second ion-doped region are alternately arranged on the first ion-doped region. The embedded gate structure is surrounded by the first oxide layer, the trapping layer, and the second oxide layer. An insulating layer is formed on the embedded gate structure. A diffusion drain is positioned atop the second ion-doped region and a conductive layer connects with the diffusion drains. The embedded gate structure is isolated from the diffusion drain with the insulating layer. Furthermore, the reading, programming, and erasing operation of the memory cell with two bits of information are provided.
    Type: Grant
    Filed: December 3, 2001
    Date of Patent: September 10, 2002
    Assignee: eMemory Technology Inc.
    Inventors: Ching-Hsiang Hsu, Kung-Hong Lee, Ching-Sung Yang
  • Publication number: 20020121659
    Abstract: A semiconductor transfer circuit and a structure thereof are provided. The transfer circuit and the structure thereof include a stack gate MOS transistor having first and second gate electrodes that are sequentially stacked and a control MOS transistor connected to the stack gate MOS transistor. A drain of the control MOS transistor is connected to the first gate electrode.
    Type: Application
    Filed: September 6, 2001
    Publication date: September 5, 2002
    Applicant: Samsung Electronics Co., Ltd.
    Inventor: Sung-Hoi Hur
  • Publication number: 20020105023
    Abstract: A process and structure for fabricating a non-volatile memory cell through the formation of a source and drain region and a charge trapping layer located therebetween is presented. E-fields for generating trapped charges are formed through using poly-edge discharge techniques wherein the gate structures of the memory cells are laterally separated from the vertical region of the source and drain regions. The gate structure forms a laterally directed e-field through the charge trapping layer to one of the source and drain regions which enables the charge to be trapped and retained in an area that is lateral to the source and drain regions. Lateral separation of the gate from the source and drain regions is maintained through the use of spacers which may take the form of insulated polysilicon structures or in an alternate embodiment may take the form of insulating spacers located on the sidewalls of the gate structure.
    Type: Application
    Filed: May 18, 2001
    Publication date: August 8, 2002
    Inventors: Tung Chen Kuo, Hsiang Lan Lung
  • Publication number: 20020106866
    Abstract: An improved method for forming a flash memory is disclosed. A self-aligned source implanted pocket located underneath and around the source line junction is formed after the field oxide between adjacent word lines is removed, and before or after the self-aligned source doping is carried out, so that the configuration of the implanted boron follows the source junction profile.
    Type: Application
    Filed: February 2, 2001
    Publication date: August 8, 2002
    Inventor: Chun Chen
  • Patent number: 6424003
    Abstract: An improved EEPROM cell with a self-aligned tunneling window is provided which is fabricated by a standard STI process so as to produce a smaller layout size and a reduced cell height. The EEPROM cell includes a floating gate, a programmable junction region, and a tunneling oxide layer separating the programmable junction region and the floating gate. The length dimension of the floating gate is less than the length dimension of the tunneling window so that the tunneling window is overlapping the floating gate. The tunneling window is self-aligned by edges forming the length dimension of the floating gate so as to form a self-aligned tunneling window.
    Type: Grant
    Filed: October 9, 1998
    Date of Patent: July 23, 2002
    Assignee: Lattice Semiconductor Corporation
    Inventors: Xiao Yu Li, Sunil D. Mehta, Christopher O. Schmidt
  • Publication number: 20020074583
    Abstract: The nonvolatile semiconductor memory device has a floating gate electrode that is formed on the semiconductor region and stores carriers injected from the semiconductor region and a control gate electrode that controls the quantity of stored carriers by applying a predetermined voltage to the floating gate electrode. The source region is formed in the semiconductor region on one of side regions of the floating gate electrode and control gate electrode, while the drain region is formed on the other of the side regions thereof. The drain region creates an electric field from which the carriers injected into the floating gate electrode are subject to an external force having an element directed from the semiconductor region to the floating gate electrode.
    Type: Application
    Filed: December 6, 2001
    Publication date: June 20, 2002
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Nobuyo Sugiyama, Shinji Odanaka, Hiromasa Fujimoto, Seiki Ogura
  • Patent number: 6407425
    Abstract: The instant invention describes a programmable neuron MOSFET structure formed on SOI substrates. A number of input capacitor structures (241, 231) are formed on a SOI substrate. The substrate region of the capacitors (330, 340) are completely isolated from each other by isolation structures (270). In addition the transistor structure (210) of the neuron MOSFET is completely isolated from the capacitor structures (241, 231) by the isolation structure (270). The neuron MOSFET also comprises a contiguous floating conductive layer (200, 230, and 240) which forms the gate structure of the capacitors (230, 240) and the floating gate (200) of the transistor structure.
    Type: Grant
    Filed: September 14, 2001
    Date of Patent: June 18, 2002
    Assignee: Texas Instruments Incorporated
    Inventors: Jeffrey A. Babcock, Scott G. Balster, Gregory E. Howard, Angelo Pinto, Philipp Steinmann
  • Patent number: 6384450
    Abstract: In a semiconductor memory device, such as a flash memory device, a conductor layer of metal or metal compound having high refractoriness, such as titanium nitride, is formed on a conductor or wiring formed by a buried diffusion layer to reduce resistance thereof. In the present invention, such conductor layer is formed by using small number of process steps and without using photolithography process. For example, after forming the buried diffusion layer for source and drain regions by ion implantation using each floating gate and dummy gate as a mask, titanium nitride is deposited throughout a substrate. Thereafter, by using oxide film growth and etching back process, an oxide film layer remaining on the titanium nitride layer between the floating gate and the dummy gate is fabricated. Then, the titanium nitride layer on the floating gate and on the dummy gate is removed by using this remained oxide film layer as a mask, without using any photolithography process.
    Type: Grant
    Filed: May 4, 1999
    Date of Patent: May 7, 2002
    Assignee: NEC Corporation
    Inventors: Ken-Ichi Hidaka, Masaru Tsukiji
  • Patent number: 6380582
    Abstract: Self-aligned etching process for providing a plurality of mutually parallel word lines in a first conducting layer deposited over a plagiarized architecture obtained starting from a semiconductor substrate on which is provided a plurality of active elements extending along separate parallel lines e.g., memory cell bit lines and comprising gate regions made up of a first conducting layer, an intermediate dielectric layer and a second conducting layer with said regions being insulated from each other by insulation regions to form said architecture with said word lines being defined photolithographically by protective strips implemented by means of: a vertical profile etching for complete removal from the unprotected areas of the first conducting layer of the second conducting layer and of the intermediate dielectric layer respectively, and a following isotropic etching of the first conducting layer.
    Type: Grant
    Filed: March 17, 2000
    Date of Patent: April 30, 2002
    Assignee: STMicroelectronics S.r.l.
    Inventors: Emilio Camerlenghi, Elio Colabella, Luca Pividori, Adriana Rebora
  • Patent number: 6380581
    Abstract: Structures and methods for novel DRAM technology compatible non volatile memory cells is provided. A non volatile memory cell structure is provided which includes a dynamic random access memory (DRAM) transistor. The non volatile memory cell includes a dynamic random access memory (DRAM) capacitor separated by an insulator layer from the DRAM transistor. An electrical via couples a first plate of the DRAM capacitor through the insulator layer to a gate of the DRAM transistor. The novel DRAM technology compatible non volatile memory cells can be fabricated on a DRAM chip with little or no modification of the DRAM optimized process flow. The novel DRAM technology compatible non volatile memory cells operate with lower programming voltages than that used by conventional non volatile memory cells, yet still hold sufficient charge to withstand the effects of parasitic capacitances and noise due to circuit operation.
    Type: Grant
    Filed: February 26, 1999
    Date of Patent: April 30, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Wendell P. Noble, Eugene H. Cloud
  • Publication number: 20020038882
    Abstract: The invention relates to an electrically erasable, non-volatile memory device, having a memory cell of the floating gate type (16), defined by a source zone, a drain zone, a channel zone (8) and a control gate zone (6), the latter being separated from the channel zone by an insulation zone (14), said five zones being implemented in a semiconductor film formed on an insulating layer (4), said memory cell being laterally insulated by one or more insulation zones (10, 12) in contact with the insulating layer.
    Type: Application
    Filed: July 28, 1998
    Publication date: April 4, 2002
    Inventors: JOEL HARTMANN, MARC BELLEVILLE
  • Patent number: 6365929
    Abstract: Disclosed is an EEPROM device, and a method of making such a device, which incorporates a self-aligned tunnel window having acceptably low gate capacitance at the tunnel oxide node, and which avoids the defects caused by field oxide induced stresses in the tunnel oxide. The EEPROM of the present invention includes a semiconductor substrate with a doped memory diffusion region. Overlying at least a portion of the memory diffusion is a tunnel oxide. Overlying at least a portion of the tunnel oxide is a floating gate structure including an extension. The tunnel window of the EEPROM of the present invention is defined within at least a portion of the tunnel oxide and having at least two edges defined by the floating gate extension, so that when a defined voltage is applied to the memory diffusion a tunnel current sufficient to change the state of the EEPROM flows between the memory diffusion and the floating gate structure.
    Type: Grant
    Filed: January 22, 1999
    Date of Patent: April 2, 2002
    Assignee: Altera Corporation
    Inventor: Richard G. Smolen
  • Patent number: 6351007
    Abstract: There is provided a quantum thin line producing method capable of forming a quantum thin line that has good surface flatness of silicon even after formation of quantum thin line and a complete electron confining region with good controllability as well as a semiconductor device employing the quantum thin line. A region of a nitride film 3 which covers a semiconductor substrate 1 on which a stepped portion 2 is formed is etched back with masking, consequently exposing an upper portion of a semiconductor substrate 1. Next, an oxide film 5 is formed by oxidizing the exposed portion of the upper portion of the semiconductor substrate 1, and a linear protruding portion 6 is formed on the semiconductor substrate along a side surface of the nitride film 3. Next, the oxide film 5 on the protruding portion 6 is partially etched to expose a tip of the protruding portion 6. Next, a thin line portion 7 is made to epitaxially grow on the exposed portion at the tip of the protruding portion 6.
    Type: Grant
    Filed: February 10, 2000
    Date of Patent: February 26, 2002
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yasumori Fukushima, Tsutomu Ashida
  • Patent number: 6348710
    Abstract: A non-volatile semiconductor memory device is divided into a first region I and a second region II. In the first region, an n+ layer is formed to be enlarged from a source region 3 to beneath a floating gate 6. A p+ layer is formed in a channel region 4. The p+ layer serves to prevent a short channel effect from occurring during read of data. A capacitance coupling ratio C1/C2 between a control gate and the floating gate is preferably 0.8 or larger. In this configuration, the non-volatile semiconductor can write, erase and read data at a high speed using a low voltage.
    Type: Grant
    Filed: April 11, 2000
    Date of Patent: February 19, 2002
    Assignee: Sanyo Electric Co., Ltd.
    Inventor: Michito Igarashi
  • Patent number: 6342716
    Abstract: A semiconductor device as a nonvolatile memory comprises dot elements which are formed out of the semiconductor or conductor fine particles and function as a floating gate. The dot elements are asymmetrically formed to a control gate and may be formed in a sidewall insulating film formed over the side face of the control gate or a select gate. When inclined or stepped portions having level differences are formed in a semiconductor substrate, the dot elements are formed on a specified portion of the inclined or stepped portions.
    Type: Grant
    Filed: May 27, 1999
    Date of Patent: January 29, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kiyoyuki Morita, Kiyoshi Morimoto, Kiyoshi Araki, Koichiro Yuki, Kazuyasu Adachi, Masayuki Endo, Ichiro Yamashita
  • Publication number: 20020003255
    Abstract: To provide a semiconductor device which can retain information for a long period of time even in a case that the tunnel insulation film is thin. A semiconductor device comprises a first insulation film 14 formed on a semiconductor substrate 10, a floating gate electrode 22 formed on the first insulation film, a second insulation 24 film formed on the floating gate electrode, and a control gate electrode 26 formed on the second insulation film. A depletion layer is formed in the floating gate electrode near the first insulation film in a state that no voltage is applied between the floating gate electrode and the semiconductor substrate.
    Type: Application
    Filed: March 22, 2001
    Publication date: January 10, 2002
    Applicant: Fujitsu Limited
    Inventors: Tatsuya Usuki, Naoto Horiguchi
  • Patent number: 6326663
    Abstract: A non-volatile memory cell, comprising a semiconductor substrate having a first conductivity type. A control region is formed of said first conductivity type in the substrate and a control region oxide formed over the control region. The cell includes a program element having a first active region of a second conductivity type formed in said substrate, a doped or implanted region adjacent to said first active region, and a gate oxide overlying at least the channel region. An active region oxide covers a portion of the first active region. A floating gate is formed over said semiconductor substrate on said active region oxide and said control region oxide.
    Type: Grant
    Filed: March 26, 1999
    Date of Patent: December 4, 2001
    Assignee: Vantis Corporation
    Inventors: Xiao-Yu Li, Steven J. Fong, Sunil D. Mehta
  • Patent number: 6323514
    Abstract: A floating gate memory device comprises a first conductive floating gate layer which is horizontally oriented and a second conductive floating gate layer which is predominantly vertically oriented. The second layer contacts the first layer to make electrical contact therewith and also defines a recess. A control gate is formed within the recess.
    Type: Grant
    Filed: July 6, 1999
    Date of Patent: November 27, 2001
    Assignee: Micron Technology, Inc.
    Inventor: David Y. Kao
  • Patent number: 6320218
    Abstract: The method of manufacturing a non-volatile semiconductor memory device comprises a step of providing a first ion implantation on the principal surface of a silicon substrate in a manner to cover a groove to form a first impurity region on the principal surface. Next, a step of providing a second ion implantation to cover the groove to form a second impurity region on the principal surface that overlaps the first impurity region at the groove and electrically connects the second source/drain region and the third source/drain region by the first impurity region. In short, the impurity region at the groove is formed by a twice ion implantation of the first and second ion implantations.
    Type: Grant
    Filed: March 22, 1999
    Date of Patent: November 20, 2001
    Assignee: Seiko Epson Corporation
    Inventor: Tomoyuki Furuhata
  • Patent number: 6300197
    Abstract: In a method of manufacturing a semiconductor device having MIS field effect transistors (MIS-FETs) with gate insulating films of two or more different film thicknesses formed on the same silicon semiconductor substrate, first, impurity for enhancing the growth rate of a gate insulating film is selectively doped into an element region on which the gate insulating film is to be formed thick and which is contained in element regions in which the MIS-FETs are to be formed. On the other hand, impurity for lowering the growth rate of a gate insulating film is selectively doped into an element region on which the gate insulating film is to be formed thin and which is contained in the element regions in which the MIS-FETs are to be formed. Next, gate insulating films are formed on the respective element regions by use of the anodic oxidation method or the like.
    Type: Grant
    Filed: June 2, 1998
    Date of Patent: October 9, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Satoshi Inaba
  • Patent number: 6300657
    Abstract: A method of making a self-aligned dynamic threshold field effect device having a dynamic threshold voltage includes depositing a mandrel layer on the surface of an SOI substrate, then etching a gate opening in the mandrel layer. The gate opening is narrowed by depositing spacer material and a highly doped region, forming a low resistance body region, is created by ion implantation. The narrowed gate opening prevents the low resistance body from connecting the source/drain regions to be formed on opposite sides of the gate-structure. A gate is formed by depositing a dielectric layer in the gate opening, and adding a layer of gate material, then chemical-mechanical polishing to the level of the mandrel layer, then removing the mandrel layer. Conventional processing is then used to create source/drain diffusion regions. The gate is connected to the body by creating a contact region at one end of the gate. The invention includes the device made by the method.
    Type: Grant
    Filed: March 27, 2000
    Date of Patent: October 9, 2001
    Assignee: International Business Machines Corporation
    Inventors: Andres Bryant, Edward J. Nowak
  • Patent number: 6297529
    Abstract: A semiconductor device is provided which is capable of suppressing an increase in the layer resistance of the gate electrode and preventing an increase of the contact resistance of the gate electrode with the silicide layer. The above properties of the semiconductor device are provided by forming the gate electrode comprising multiple layers, and the lowermost layer of the gate electrode is doped with an impurity, and other upper layers are formed undoped.
    Type: Grant
    Filed: April 5, 1999
    Date of Patent: October 2, 2001
    Assignee: NEC Corporation
    Inventor: Kiyotaka Imai
  • Patent number: 6294810
    Abstract: An EEPROM cell is described that is programmed and erased by electron tunneling at separate regions, an edge of a tunneling drain and a sense transistor channel. The EEPROM cell has three transistors formed in a semiconductor substrate. The three transistors are a tunneling transistor (NMOS), a sense transistor (NMOS) and a read transistor (NMOS). Electron tunneling occurs to program the EEPROM cell through a sense tunnel oxide layer by electron tunneling across an entire portion of a sense channel upon incurrence of a sufficient voltage potential between a floating gate and the sense channel. Electron tunneling also occurs to erase the EEPROM cell through a tunnel oxide layer be electron tunneling at an edge of a tunneling drain upon incurrence of a sufficient voltage potential between the floating gate and the tunneling drain.
    Type: Grant
    Filed: December 22, 1998
    Date of Patent: September 25, 2001
    Assignee: Vantis Corporation
    Inventors: Xiao-Yu Li, Steven J. Fong
  • Patent number: 6294811
    Abstract: A two transistor EEPROM cell is described that is erased by electron tunneling across an entire portion of a tunneling channel and programmed by electron tunneling at an edge of a tunneling drain.
    Type: Grant
    Filed: February 5, 1999
    Date of Patent: September 25, 2001
    Assignee: Vantis Corporation
    Inventors: Steven J. Fong, Xiao-Yu Li
  • Patent number: 6278154
    Abstract: An object of the present invention is to provide a semiconductor apparatus and a method of manufacturing the same, in which dispersion of a threshold voltage Vth of a transistor at every transistor is reduced to remove generation of fixed charges in a gate insulation film and a surface level to stabilize the operation of the semiconductor apparatus. A semiconductor apparatus having a MIS transistor (1), wherein a gate electrode (4) of said MIS transistor (1), which mainly contributes to the operation of a circuit, is continuously formed to a position above a bypass film (8) made of an insulation film through which a leak current is able to easily flow as compared with a gate insulation film (7) of said MIS transistor (1) under the same voltage.
    Type: Grant
    Filed: November 7, 1997
    Date of Patent: August 21, 2001
    Assignee: Sony Corporation
    Inventor: Hideshi Abe
  • Patent number: 6268622
    Abstract: A non-volatile memory device and a fabrication method thereof, wherein the non-volatile memory device includes first and second memory cells in a region of a semiconductor substrate where a word line crosses a bit line. Thus, one word line can control the operation of two memory cells, and the device requires less area. Further an intergate dielectric layer extends to the side walls of the floating gate allowing more area and a higher coupling ratio. A lower voltage may therefore be applied to the control gate. During an erasing operation the path of electrons can be redirected toward the substrate. Deterioration of a tunneling insulating layer is thereby reduced or eliminated.
    Type: Grant
    Filed: June 2, 1999
    Date of Patent: July 31, 2001
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Moon Shone, Ji-nam Kim
  • Patent number: 6268623
    Abstract: Disclosed is a method and apparatus for evaluating margin voltages in single poly EEPROM cells. Briefly, the invention involves shifting the cell's threshold voltage higher, resulting in a corresponding rise in the margin voltage, so that testing for the erase margin may be conducted in the positive voltage range. The present invention implements a variety of solutions to the problem, including both innovations in cell processing and circuitry. In one embodiment, the process steps employed to create the floating gate transistor are changed in order to increase its threshold voltage. Alternatively, or in combination with these general process changes, the width of the floating gate transistor may be reduced, resulting in a corresponding increase in the margin voltage.
    Type: Grant
    Filed: December 22, 1997
    Date of Patent: July 31, 2001
    Assignee: Altera Corporation
    Inventors: Raminda U. Madurawe, Myron W. Wong, John C. Costello, James D. Sansbury, Bruce E. Mielke
  • Patent number: 6259132
    Abstract: Array of electrically programmable non-volatile memory cells, each cell comprising a stacked-gate MOS transistor having a lower gate electrode, an upper gate electrode coupled to a row of the array, a first electrode associated with a column of the array and a second electrode separated from the first electrode by a channel region underlying said lower gate electrode, the first electrode, the second electrode and the channel region being formed in a layer of semiconductor material of a first conductivity type and having a second conductivity type, comprising at least one ROM memory cell which identically to the electrically programmable non-volatile memory cells comprises a stacked-gate MOS transistor and is associated with a respective row and a respective column of the array, the ROM cell including means for allowing or not allowing the electrical separation between said respective column and the second electrode of the ROM cell, if the ROM cell must store a first logic state or, respectively, a second logi
    Type: Grant
    Filed: July 2, 1998
    Date of Patent: July 10, 2001
    Assignee: STMicroelectronics S.r.l.
    Inventor: Federico Pio
  • Patent number: 6259142
    Abstract: A semiconductor integrated circuit having a multiple split gate is forming using a first polysilicon layer and a second polysilicon layer to form alternating first and second gate electrodes within an active area. The alternating gate electrodes are electrically isolated from one another by means of a gate insulating layer that is formed adjacent the side-walls of each firs gate electrode. Source and drain regions are formed adjacent the ends of the multiple split gate to define a channel region.
    Type: Grant
    Filed: April 7, 1998
    Date of Patent: July 10, 2001
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Robert Dawson, Mark I. Gardner, Frederick N. Hause, H. Jim Fulford, Jr., Mark W. Michael, Bradley T. Moore, Derick J. Wristers
  • Patent number: 6255686
    Abstract: In a semiconductor storage device, an access transistor, which has a gate electrode and a pair of impurity diffusion layers, is formed at a device activation region defined by a device isolation structure of a semiconductor substrate. A first insulating film, which has a first contact hole for exposing a portion of the surface of one of the pair of impurity diffusion layers, is formed over the access transistor. A protective film, which has a second contact hole formed on the first contact hole, is formed on the first insulating film. A second insulating film is formed on the side wall faces of the first and second contact holes. A memory capacitor has a lower electrode and an upper part electrode which are opposed each other and are capacitive-coupled through a dielectric film.
    Type: Grant
    Filed: July 30, 1998
    Date of Patent: July 3, 2001
    Assignee: Nippon Steel Corporation
    Inventors: Hideki Takeuchi, Hirohiko Izumi
  • Patent number: 6252273
    Abstract: A programmable interconnect cell for selectively connecting circuit nodes of a field programmable integrated circuit array in a semiconductor substrate includes a switch field effect transistor, a sense field effect transistor, and an electron tunneling device with the transistors and electron tunneling device having interconnected floating gates and interconnected control gates. The floating gates comprise a first polysilicon layer which is restricted to each cell, and the control gates comprise a second polysilicon layer which extends to adjacent cells in the row. The source/drain regions of the sense transistor extend to source/drain regions of sense amplifiers in adjacent rows. Programming and erasing of the switch transistor is effected entirely by electron tunneling in the electron tunneling device.
    Type: Grant
    Filed: August 24, 1998
    Date of Patent: June 26, 2001
    Assignee: Actel Corporation
    Inventors: Robert M. Salter, III, Robert J. Lipp, Kyung Joon Han, Jack Zezhong Peng
  • Patent number: 6252275
    Abstract: A non-volatile random access memory (NVRAM) structure comprising an injector element in a single crystal silicon substrate; an insulator layer over the substrate; a silicon-on-insulator (SOI) layer over the insulator layer; and a sensing element in the SOI layer overlying the injector element. The NVRAM structure may further comprise a gate above the SOI layer, a floating gate in the insulator layer, or both.
    Type: Grant
    Filed: January 7, 1999
    Date of Patent: June 26, 2001
    Assignee: International Business Machines Corporation
    Inventors: John M. Aitken, Steven W. Mittl, Alvin W. Strong
  • Patent number: 6249020
    Abstract: A floating gate transistor has a reduced barrier energy at an interface between a gallium nitride (GaN) or gallium aluminum nitride (GaAlN) floating gate an adjacent gate insulator, allowing faster charge transfer across the gate insulator at lower voltages. Data is stored as charge on the floating gate. The data charge retention time on the floating gate is reduced. The data stored on the floating gate is dynamically refreshed. The floating gate transistor provides a dense and planar dynamic electrically alterable and programmable read only memory (DEAPROM) cell adapted for uses such as for a dynamic random access memory (DRAM) or a dynamically refreshed flash EEPROM memory. The floating gate transistor provides a high gain memory cell and low voltage operation.
    Type: Grant
    Filed: August 27, 1998
    Date of Patent: June 19, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Leonard Forbes, Kie Y. Ahn
  • Patent number: 6242782
    Abstract: The provision of an isolation gate connecting unassociated active areas of adjacent transistors formed in a semiconductor substrate provides effective isolation of the adjacent transistors with no additional process steps required. The isolation gate is tied to a reference to ensure that a channel between the unassociated active areas is not formed, and effective isolation is provided. The adjacent transistors are cross coupled to form sense amplifiers for dynamic random access memory devices.
    Type: Grant
    Filed: July 29, 1998
    Date of Patent: June 5, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Stephen L. Casper, Brian M. Shirley, Kevin G. Duesman
  • Patent number: 6236085
    Abstract: A semiconductor memory device comprising a source and a drain formed in a P-type semiconductor substrate and a floating gate and a control gate constituting a two-layer gate. Electric-field moderating layer is provided in the P-type semiconductor substrate to contact with a side face of the drain. P-type region is formed in contact with channel region side surface and bottom surface of the electric-field moderating layer. P-type region lower part of the P-type region in contact with the bottom surface of the electric-field moderating layer is given a lower impurity concentration than P-type region side part formed at the channel region side of the electric-field moderating layer. By this means it is possible to increase the writing speed of the semiconductor memory device while suppressing delay in the switching speed during reading operation.
    Type: Grant
    Filed: November 10, 1997
    Date of Patent: May 22, 2001
    Assignee: Denso Corporation
    Inventors: Tsutomu Kawaguchi, Mitsutaka Katada
  • Patent number: 6232630
    Abstract: The reliability of a tunnel oxide is improved by light doping of the floating gate, as with phosphorous or arsenic atoms. Doping can be implemented by ion implantation or by in situ deposition. The relatively low dopant concentration further enhances charge retention on the floating gate.
    Type: Grant
    Filed: July 7, 1999
    Date of Patent: May 15, 2001
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Mark T. Ramsbey, Tuan Pham, Yu Sun, Kenneth Wo-Wai Au, David H. Chi
  • Patent number: 6232635
    Abstract: An article and method of manufacturing a semiconductor flash cell. The method includes producing an isolation formation layer on a silicon substrate, forming an oxide on the isolation formation layer, growing a tunnel oxide layer thereon, depositing a first poly silicon layer, masking and etching the first poly silicon layer, depositing a second poly silicon layer and performing a blanket etch back step, forming an oxide/nitride/oxide layer forming a third poly-silicon layer and depositing a silicide layer thereon.
    Type: Grant
    Filed: April 6, 2000
    Date of Patent: May 15, 2001
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Larry Yu Wang, Steven C. Avanzino, Jeffrey A. Shields, Stephen Keetai Park
  • Patent number: 6228713
    Abstract: A method to make a self-aligned floating gate in a memory device. The method patterns the floating gate (FG) using the trench etch for the shallow trench isolation (STI). Because the floating gate (FG) is adjacent to the raised STI, sharp corners are eliminated between the FG and CG thereby increasing the effectiveness of the intergate dielectric layer. The method includes: forming an first dielectric layer (gate oxide) and a polysilicon layer over a substrate, etching through the first dielectric oxide layer and the polysilicon layer and into the substrate to form a trench. The remaining first dielectric layer and polysilicon layer function as a tunnel dielectric layer and a floating gate. The trench is filled with an isolation layer. The masking layer is removed. An intergate dielectric layer and a control gate are formed over the floating gate and the isolation layer.
    Type: Grant
    Filed: June 28, 1999
    Date of Patent: May 8, 2001
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Yelehanka Ramachandramurthy Pradeep, Vijay Kumar Chhagan, Jie Yu, Mei Sheng Zhou
  • Patent number: 6229175
    Abstract: A nonvolatile memory includes a charge transfer layer, having a low barrier height, between the floating gate electrode and the control gate electrode. Accordingly, the nonvolatile memory avoids the problem in which the number of program and erasure cycles is decreased as a result of degradation of a tunnel oxide film.
    Type: Grant
    Filed: March 19, 1999
    Date of Patent: May 8, 2001
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Hidetsugu Uchida
  • Patent number: 6225660
    Abstract: The present invention discloses an EPLD cell includes a semiconductor substrate, tunnel buried layer, control gate, and floating gate. The tunnel buried layer and control gate, which has a three-dimensional contour, are formed under the surface of semiconductor substrate by implanting N-type dopant. The floating gate formed completely over the tunnel buried layer and partially over the control gate, is insulating from them by oxide layers. Because of the three-dimensional contour of control gate, the overlapped area between the floating gate and control gate could be increase without expanding horizontal area of the cell. Therefore, the efficiency of the cell can be improved without degrading the integration in applying the cell.
    Type: Grant
    Filed: October 15, 1999
    Date of Patent: May 1, 2001
    Assignee: Worldwide Semiconductor Manfacturing Corp.
    Inventor: Chia-Chen Liu
  • Patent number: 6204123
    Abstract: A vertical floating gate transistor includes an epitaxially formed channel between its lower source/drain region and upper source/drain region, with a floating gate electrode in a trench that extends vertically through those regions and a control or programming gate electrode above and separated from the floating gate electrode. A process for forming the vertical floating gate transistor implants the substrate to provide the lower source/drain region, then forms an epitaxial layer that provides the channel over the previously formed lower source/drain region. Then, the upper source/drain region is implanted above the lower source/drain region and epitaxial channel layer, followed by formation of a vertical trench and the floating and control gates. Forming the epitaxial layer over a previously implanted lower source/drain region allows independent control of the resistivity of the lower source/drain region, such that it can have low resistivity, facilitating device symmetry.
    Type: Grant
    Filed: October 30, 1998
    Date of Patent: March 20, 2001
    Assignees: Sony Corporation, Sony Electronics Inc.
    Inventor: Kiyoshi Mori
  • Patent number: 6188111
    Abstract: In a semiconductor device including a MOSFET, a first semiconductor layer is formed over a silicon substrate and has a gate region. Further, a second semiconductor layer is formed over the first semiconductor layer with a gate oxide film therebetween, and has an active region. The active region has a source region, a drain region and a channel region. An insulator layer on the active region encloses a back gate wiring layer.
    Type: Grant
    Filed: March 31, 1998
    Date of Patent: February 13, 2001
    Assignee: NEC Corporation
    Inventor: Kouichi Kumagai
  • Patent number: 6184554
    Abstract: Memory cell having a floating gate with lateral edges which are aligned directly above edges of the active area in the substrate, a control gate positioned directly above the floating gate, and a select gate spaced laterally from the control gate. The floating gate has a bottom wall and side walls which face corresponding walls of the control gate in capacitive coupling relationship, with the height of the side walls being on the order of 80 to 160 percent of the width of the bottom wall. In some embodiments, the floating gate is wider than the overlying control gate and has projecting portions which overlie the source and drain regions of the stack transistor.
    Type: Grant
    Filed: October 5, 1999
    Date of Patent: February 6, 2001
    Assignee: Actrans System Inc.
    Inventor: Chiou-Feng Chen
  • Patent number: 6180977
    Abstract: A method is provided for fabricating a self-aligned edge implanted split-gate flash memory comprising a semiconductor substrate of a first conductivity type having separated first and second regions of a second conductivity type formed therein, the first and second regions defining a substrate channel region therebetween; a floating gate separated from a doped region in the substrate by an oxide layer; a control gate partially overlying and separated by an insulator from said floating gate; said floating gate having thin portions and thick portions; and said thin portions of said floating gate overlying twice doped regions in said semiconductor substrate to reduce surface leakage current and improve program speed of the memory cell.
    Type: Grant
    Filed: September 3, 1999
    Date of Patent: January 30, 2001
    Assignee: Taiwan Semiconductor Manufacturing Company
    Inventors: Yai-Fen Lin, Hung-Cheng Sung, Chia-Ta Hsieh, Di-Son Kuo
  • Patent number: 6177702
    Abstract: An avalanche breakdown from the buried channel to the substrate in a semiconductor component, in particular an EEPROM, is avoided by a local thickened portion of the gate dielectric. The thickened portion establishes an insulation structure at the transition to the tunnel dielectric. This produces a potential barrier which enables the gate dielectric and the tunnel dielectric to have the same thickness. The space requirement of such a cell is reduced.
    Type: Grant
    Filed: October 9, 1998
    Date of Patent: January 23, 2001
    Assignee: Infineon Technologies AG
    Inventor: Ronald Kakoschke
  • Patent number: 6166954
    Abstract: A single-poly, floating gate memory cell includes a PMOS write and an NMOS read path. The memory cell's write path includes a PMOS half-transistor coupled in series with a PMOS write select transistor. The PMOS half-transistor serves as a storage element and includes a P+ drain region, a polysilicon floating gate, and a buried control gate. The read path includes an NMOS read transistor coupled in series with an NMOS read select transistor, where the floating gate of the PMOS half-transistor programming element serves as the gate of the NMOS read transistor. The memory cell is programmed along the PMOS write path by injecting electrons from a P-channel region of the PMOS half-transistor into the floating gate, and is read along the NMOS read path by conducting a channel current through an N-channel region of the NMOS read transistor.
    Type: Grant
    Filed: July 14, 1999
    Date of Patent: December 26, 2000
    Assignee: Programmable Microelectronics Corporation
    Inventor: Geeing-Chuan Chern
  • Patent number: RE37308
    Abstract: The cell is formed of a selection transistor, a detection transistor and a tunnel condenser. The detection Transistor has its own control gate formed with an n+ diffusion which is closed and isolated from those of the other cells of the same memory.
    Type: Grant
    Filed: January 23, 1995
    Date of Patent: August 7, 2001
    Assignee: STMicroelectronics S.r.l.
    Inventors: Paolo G. Cappelletti, Giuseppe Corda, Carlo Riva