With Gate Electrode Of Controlled Workfunction Material (e.g., Low Workfunction Gate Material) Patents (Class 257/407)
  • Patent number: 7009279
    Abstract: In semiconductor devices, a semiconductor device is provided which is high in reliability while suppressing changes in characteristics such as threshold voltages. In a semiconductor device which has a gate dielectric film above a semiconductor substrate and also has above the gate dielectric film a gate electrode film made of silicon germanium chosen as its main constituent material, or alternatively in a semiconductor device which has beneath the gate dielectric film a channel made of silicon as its main constituent material and which has below the channel a channel underlayer film made of silicon germanium as its main constituent material, a specifically chosen dopant, such as cobalt (Co) or carbon (C) or nitrogen (N), is added to the gate electrode and the channel underlayer film, for use as the unit for suppressing diffusion of germanium in the gate electrode or in the channel underlayer film.
    Type: Grant
    Filed: May 12, 2004
    Date of Patent: March 7, 2006
    Assignees: Hitachi, Ltd., Trecenti Technologies, Inc.
    Inventors: Shingo Nasu, Tomio Iwasaki, Hiroyuki Ohta, Yukihiro Kumagai, Shuji Ikeda
  • Patent number: 7005716
    Abstract: Methods for forming dual-metal gate CMOS transistors are described. An NMOS and a PMOS active area of a semiconductor substrate are separated by isolation regions. A metal layer is deposited over a gate dielectric layer in each active area. Silicon ions are implanted into the metal layer in one active area to form an implanted metal layer which is silicided to form a metal silicide layer. Thereafter, the metal layer and the metal silicide layer are patterned to form a metal gate in one active area and a metal silicide gate in the other active area wherein the active area having the gate with the higher work function is the PMOS active area. Alternatively, both gates may be metal silicide gates wherein the silicon concentrations of the two gates differ. Alternatively, a dummy gate may be formed in each of the active areas and covered with a dielectric layer. The dielectric layer is planarized thereby exposing the dummy gates. The dummy gates are removed leaving gate openings to the semiconductor substrate.
    Type: Grant
    Filed: May 25, 2004
    Date of Patent: February 28, 2006
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Wenhe Lin, Mei-Sheng Zhou, Kin Leong Pey, Simon Chooi
  • Patent number: 6998686
    Abstract: Described is a CMOS transistor structure with a multi-layered gate electrode structure and a method of fabrication. The gate electrode structure has a three-layered metallic gate electrode and a polysilicon layer. The first metallic layer acts as a barrier to prevent the second metallic layer from reacting with an underlying dielectric. The second metallic layer acts to set the work function of the gate electrode structure. The third metallic layer acts as a barrier to prevent the second metallic layer from reacting with the polysilicon layer. The method of fabricating the gate electrode structure includes forming the three metallic layers thick enough that each layer provides the barrier and work-function setting functions mentioned above, but also thin enough that a subsequent wet-etch can be performed without excessive undercutting of the metallic layers.
    Type: Grant
    Filed: August 28, 2002
    Date of Patent: February 14, 2006
    Assignee: Intel Corporation
    Inventors: Robert Chau, Mark Doczy, Brian Doyle, Jack Kavalieros
  • Patent number: 6995434
    Abstract: A semiconductor device capable of suppressing increase of the capacitance while suppressing a thin-line effect of a silicide film is obtained. This semiconductor device comprises a first silicon layer formed on a semiconductor substrate through a gate insulator film with an upper portion and a lower portion larger in width than a central portion for serving as a gate electrode and a first silicide film formed on the first silicon layer for serving as the gate electrode.
    Type: Grant
    Filed: September 29, 2003
    Date of Patent: February 7, 2006
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Ryosuke Usui, Kazuhiro Sasada
  • Patent number: 6992357
    Abstract: A semiconductor device comprises an n-type MIS transistor comprising a first gate insulating film and a first gate electrode including an MSix film formed on the first gate insulating film, where M represents a metal element selected from tungsten and molybdenum and x is greater than 1, i.e., x>1; and a p-type MIS transistor comprising a second gate insulating film and a second gate electrode including an MSiy film formed on the second gate insulating film, where y is not less than 0 and less than 1, i.e., 0?y<1.
    Type: Grant
    Filed: December 23, 2002
    Date of Patent: January 31, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kouji Matsuo, Kazuaki Nakajima
  • Patent number: 6992358
    Abstract: Disclosed is a semiconductor device comprising an underlying insulating film having a depression, a semiconductor structure which includes a first semiconductor portion having a portion formed on the underlying insulating film and a first overlap portion which overlaps the depression, a second semiconductor portion having a portion formed on the underlying insulating film and a second overlap portion which overlaps the depression, and a third semiconductor portion disposed between the first and second semiconductor portions and having a portion disposed above the depression, wherein overlap width of the first overlap portion and overlap width of the second overlap portion are equal to each other, a gate electrode including a first electrode portion covering upper and side surfaces of the third semiconductor portion and a second electrode portion formed in the depression, and a gate insulating film interposed between the semiconductor structure and the gate electrode.
    Type: Grant
    Filed: June 24, 2004
    Date of Patent: January 31, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Katsuhiko Hieda, Kazuya Matsuzawa, Daisuke Hagishima
  • Patent number: 6974999
    Abstract: It is an object to suppress a change in a characteristic of a semiconductor device with a removal of a hard mask while making the most of an advantage of a gate electrode formed by using the hard mask. A gate electrode (3) is formed by etching using a hard mask as a mask and the hard mask remains on an upper surface of the gate electrode (3) at a subsequent step. In the meantime, the upper surface of the gate electrode (3) can be therefore prevented from being unnecessarily etched. The hard mask is removed after ion implantation for forming a source-drain region. Consequently, the influence of the removal of the hard mask on a characteristic of a semiconductor device can be suppressed. In that case, moreover, a surface of a side wall (4) is also etched by a thickness of (d) so that an exposure width of an upper surface of the source-drain region is increased. After the removal of the hard mask, it is easy to salicide the gate electrode (3) and to form a contact on the gate electrode (3).
    Type: Grant
    Filed: October 7, 2002
    Date of Patent: December 13, 2005
    Assignee: Renesas Technology Corp.
    Inventor: Tsuyoshi Sugihara
  • Patent number: 6967379
    Abstract: A semiconductor device comprises a semiconductor substrate, an N-channel MISFET and a P-channel MISFET provided on the semiconductor substrate, each of the N- and P-channel MISFETs being isolated by an isolation region and having a gate insulating film, a first gate electrode film provided on the gate insulating film of the N-channel MISFET and composed of a first metal silicide, a second gate electrode film provided on the gate insulating film of the P-channel MISFET and composed of a second metal silicide made of a second metal material different from a first metal material composing the first metal silicide, and a work function of the first gate electrode film being lower than that of the second gate electrode film.
    Type: Grant
    Filed: September 10, 2003
    Date of Patent: November 22, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Kouji Matsuo
  • Patent number: 6964891
    Abstract: A semiconductor layer with a threshold voltage for n-channel is formed and patterned to TFT island areas. A gate insulating film is deposited. The first gate electrode layer is formed and pattered to form an opening. Phosphorous ions are implanted into a p-channel TFT in the opening to set threshold voltage for p-channel TFT. A second gate electrode layer is formed and patterned to form second gate electrodes. By using the first gate electrode layer as a mask, boron ions are implanted at a high concentration to form source/drain regions of the p-channel TFT. By using the second gate electrodes as a mask, the first gate electrode layer is etched to form gate electrodes. Phosphorous ions are implanted at a low concentration to form LDD regions. By using a fourth mask, P ions are implanted at a high concentration to form source/drain regions of n-channel TFTs.
    Type: Grant
    Filed: January 27, 2004
    Date of Patent: November 15, 2005
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Kazushige Hotta
  • Patent number: 6965123
    Abstract: A CMOS-compatible FET has a reduced electron affinity polycrystalline or microcrystalline SiC gate that is electrically isolated (floating) or interconnected. The SiC material composition is selected to establish the barrier energy between the SiC gate and a gate insulator. In a memory application, such as a flash EEPROM, the SiC composition is selected to establish a lower barrier energy to reduce write and erase voltages and times or accommodate the particular data charge retention time needed for the particular application. In a light detector or imaging application, the SiC composition is selected to provide sensitivity to the desired wavelength of light. Unlike conventional photodetectors, light is absorbed in the floating gate, thereby ejecting previously stored electrons therefrom. Also unlike conventional photodetectors, the light detector according to the present invention is actually more sensitive to lower energy photons as the semiconductor bandgap is increased.
    Type: Grant
    Filed: October 18, 2000
    Date of Patent: November 15, 2005
    Assignee: Micron Technology, Inc.
    Inventors: Leonard Forbes, Kie Y. Ahn
  • Patent number: 6964893
    Abstract: A gate electrode of an n-type MIS transistor includes a first metal-containing film, which is formed in contact with a gate insulation film and has a Fermi level on a conductive band side from a substantial center of a band gap of a semiconductor substrate, and a second metal-containing film formed on the first metal-containing film and having a lower resistance than the first metal-containing film. A gate electrode of a p-type MIS transistor includes a conductive coating film, which is formed in contact with the gate insulation film and has a Fermi level on a valence band side from a substantial center of the band gap of the semiconductor substrate, and the second metal-containing film formed on the conductive coating film and having a lower resistance than the conductive coating film.
    Type: Grant
    Filed: March 30, 2004
    Date of Patent: November 15, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Kouji Matsuo
  • Patent number: 6936508
    Abstract: Semiconductor devices and fabrication methods are provided, in which metal transistor gates are provided for MOS transistors. Metal boride is formed above a gate dielectric to create PMOS gate structures and metal nitride is formed over a gate dielectric to provide NMOS gate structures. The metal portions of the gate structures are formed from an initial starting material that is either a metal boride or a metal nitride, after which the starting material is provided with boron or nitrogen in one of the PMOS and NMOS regions through implantation, diffusion, or other techniques, either before or after formation of the conductive upper material, and before or after gate patterning. The change in the boron or nitrogen content of the starting material provides adjustment of the material work function, thereby tuning the threshold voltage of the resulting PMOS or NMOS transistors.
    Type: Grant
    Filed: September 12, 2003
    Date of Patent: August 30, 2005
    Assignee: Texas Instruments Incorporated
    Inventors: Mark Visokay, Luigi Colombo, James J. Chambers
  • Patent number: 6921935
    Abstract: A semiconductor memory cell structure and method for forming the same. The memory cell is formed on a surface of a substrate and includes an active region formed in the substrate, an epitaxial post formed on the surface of the substrate over the active region. The epitaxial post has at least one surface extending outwardly from the surface of the substrate and another surface opposite of the surface of the substrate. A gate structure is formed adjacent to at least a portion of all the outwardly extending surfaces of the epitaxial post, and a capacitor formed on an exposed surface of the epitaxial post.
    Type: Grant
    Filed: May 26, 2004
    Date of Patent: July 26, 2005
    Assignee: Micron Technology, Inc.
    Inventor: Kris K. Brown
  • Patent number: 6921949
    Abstract: A semiconductor integrated circuit device is comprised of an amplifier circuit having first and second PMOS and NMOS transistors. The first PMOS transistor has a gate electrode and a drain electrode connected together. The second PMOS transistor has a gate electrode connected to the gate electrode of the first PMOS transistor and a course electrode connected to a course electrode of the first PMOS transistor. The first NMOS transistor has a drain electrode connected to the drain electrode of the first PMOS transistor and a gate electrode sat as a first input terminal. The second NMOS transistor has a drain electrode connected to a drain electrode of the second PMOS transistor, a source electrode connected to a sourse electrode of the first NMOS transistor, and a gate electrode sat as a second input terminal. At least one of the first NMOS transistor and the second NMOS transistor is comprised of a buried channel transistor.
    Type: Grant
    Filed: June 30, 2003
    Date of Patent: July 26, 2005
    Assignee: Seiko Instruments Inc.
    Inventors: Hirofumi Harada, Jun Osanai
  • Patent number: 6914311
    Abstract: The claimed invention relates to a semiconductor device and a method of fabricating the semiconductor device. More particularly, the claimed invention relates to a method of fabricating the semiconductor device in which parts of a gate electrode at the ends of a channel are lightly doped compared to the center part of the gate electrode, thereby eliminating a hump on a subthreshold current slope. To achieve the objects of the claimed invention, there is provided a semiconductor device that includes a semiconductor substrate divided into an isolation region and an active region. A gate oxide film is formed on a first upper surface of the active region. A gate electrode is formed on a second upper surface of the gate oxide film, the gate electrode having a first part and a second part. The first part is more lightly doped with impurities than the second part. A channel is formed in an upper end of the active region proximate the gate electrode.
    Type: Grant
    Filed: November 13, 2002
    Date of Patent: July 5, 2005
    Assignee: Hynix Semiconductor Inc.
    Inventors: Jong-Wan Jung, Jeong Seok Nam
  • Patent number: 6909154
    Abstract: Numerous embodiments of a method and apparatus for a sacrificial annealing layer are disclosed. In one embodiment, a method of forming a sacrificial annealing layer for a semiconductor device comprises forming one or more sacrificial layers on at least a portion of the top surface of a semiconductor device, annealing at least a portion of the device, and removing a substantial portion of the one or more sacrificial layers, where the removing results in no substantial physical alterations to the device.
    Type: Grant
    Filed: November 17, 2003
    Date of Patent: June 21, 2005
    Assignee: Intel Corporation
    Inventors: Mark Y. Liu, Justin K. Brask
  • Patent number: 6909186
    Abstract: Structure and methods of fabrication are disclosed for an enhanced FET devices in which dopant impurities are prevented from diffusing through the gate insulator. The structure comprises a Si:C, or SiGe:C, layer which is sandwiched between the gate insulator and a layer which is doped with impurities in order to provide a preselected workfunction. It is further disclosed how this, and further improvements for FET devices, such as raised source/drain and multifaceted gate on insulator, MODFET on insulator are integrated with strained Si based layer on insulator technology.
    Type: Grant
    Filed: May 1, 2003
    Date of Patent: June 21, 2005
    Assignee: International Business Machines Corporation
    Inventor: Jack Oon Chu
  • Patent number: 6905976
    Abstract: The structure and method of forming a notched gate MOSFET disclosed herein addresses such problems as device reliability. A gate dielectric (e.g. gate oxide) is formed on the surface of an active area on the semiconductor substrate, preferably defined by an isolation trench region. A layer of polysilicon is then deposited on the gate dielectric. This step is followed by depositing a layer of silicon germanium) (SiGe). The sidewalls of the polysilicon layer are then laterally etched, selective to the SiGe layer to create a notched gate conductor structure, with the SiGe layer being broader than the underlying polysilicon layer. Sidewall spacers are preferably formed on sidewalls of the SiGe layer and the polysilicon layer. A silicide layer is preferably formed as a self-aligned silicide from a polysilicon layer deposited over the SiGe layer, to reduce resistance of the gate conductor. One or more other processing steps (e.g.
    Type: Grant
    Filed: May 6, 2003
    Date of Patent: June 14, 2005
    Assignee: International Business Machines Corporation
    Inventors: Jochen Beintner, Yujun Li, Naim Moumen, Porshia Shane Wrschka
  • Patent number: 6905922
    Abstract: A semiconductor device having a plurality of silicidation steps is provided. In the preferred embodiment in which the semiconductor device is a MOSFET, the source/drain regions are silicided. A dielectric layer is formed and the etch stop layer is removed from the gate electrode of the MOSFET. A second silicidation process is performed to silicide the gate electrode. The process may be performed individually for each transistor, allowing the electrical characteristics of each transistor to be determined individually.
    Type: Grant
    Filed: October 3, 2003
    Date of Patent: June 14, 2005
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.
    Inventors: Chuan-Yi Lin, Yee-Chia Yeo
  • Patent number: 6894356
    Abstract: A static random access memory (SRAM) cell is given increased stability and latch-up immunity by fabricating the PMOS load transistors of the SRAM cell to have a very low drain/source dopant concentration. The drain/source regions of the PMOS load transistors are formed entirely by a P?? blanket implant. The PMOS load transistors are masked during subsequent implant steps, such that the drain/source regions of the PMOS load transistors do not receive additional P-type (or N-type) dopant. The P?? blanket implant results in PMOS load transistors having drain/source regions with dopant concentrations of 1e17 atoms/cm3 or less. The dopant concentration of the drain/source regions of the PMOS load transistors is significantly lower than the dopant concentration of lightly doped drain/source regions in PMOS transistors used in peripheral circuitry.
    Type: Grant
    Filed: March 15, 2002
    Date of Patent: May 17, 2005
    Assignee: Integrated Device Technology, Inc.
    Inventor: Jeong Yeol Choi
  • Patent number: 6891233
    Abstract: Methods for forming dual-metal gate CMOS transistors are described. An NMOS and a PMOS active area of a semiconductor substrate are separated by isolation regions. A metal layer is deposited over a gate dielectric layer in each active area. Oxygen ions are implanted into the metal layer in one active area to form an implanted metal layer which is oxidized to form a metal oxide layer. Thereafter, the metal layer and the metal oxide layer are patterned to form a metal gate in one active area and a metal oxide gate in the other active area wherein the active area having the gate with the higher work function is the PMOS active area. Alternatively, both gates may be metal oxide gates wherein the oxide concentrations of the two gates differ. Alternatively, a dummy gate may be formed in each of the active areas and covered with a dielectric layer. The dielectric layer is planarized thereby exposing the dummy gates. The dummy gates are removed leaving gate openings to the semiconductor substrate.
    Type: Grant
    Filed: December 16, 2003
    Date of Patent: May 10, 2005
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Wenhe Lin, Mei-Sheng Zhou, Kin Leong Pey, Simon Chooi
  • Patent number: 6891234
    Abstract: An electrical switching device includes a semiconductor having a channel therein which is proximate to at least on channel tap in an extension region and also to a gate. A conductor (e.g., a metal) is disposed proximate to the extension region but is electrically isolated from both the extension region and the gate (e.g., through the use of one or more insulators). The conductor has a workfunction outside of the bandgap of a semiconductor in the extension region and therefore includes a layer of charge in the extension region. The magnitude and polarity of this layer of charge is controlled through selection of the metal, the semiconductor, and the insulator.
    Type: Grant
    Filed: April 26, 2004
    Date of Patent: May 10, 2005
    Assignee: Acorn Technologies, Inc.
    Inventors: Daniel J. Connelly, Carl Faulkner, Daniel E. Grupp
  • Patent number: 6888206
    Abstract: An n-type substrate surface and a p+ region are provided adjacent to each other, on upper surfaces of which an insulation film, a shield and a conductor are formed in this order. The shield is connected to the conductor. The shield and the conductor are insulated from the n-type substrate surface by the insulation film. Even when polarization occurs in a mold provided over a semiconductor device due to a potential distribution along the substrate surface of the semiconductor device, the conductive shield can prevent the substrate from being affected by the polarization in the mold, allowing avoidance of an adverse influence of deterioration in breakdown voltage and the like.
    Type: Grant
    Filed: November 21, 2002
    Date of Patent: May 3, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tetsuo Takahashi, Hideki Takahashi
  • Patent number: 6888205
    Abstract: A metal oxide semiconductor transistor integrated in a wafer of semiconductor material includes a gate structure located on a surface of the wafer and includes a gate oxide layer. The gate oxide layer includes a first portion having a first thickness and a second portion having a second thickness differing from the first thickness.
    Type: Grant
    Filed: December 20, 2002
    Date of Patent: May 3, 2005
    Assignee: STMicroelectronics S.r.l.
    Inventors: Alessandro Moscatelli, Giuseppe Croce
  • Patent number: 6879009
    Abstract: A method of fabricating integrated circuits includes forming MOSFETs with gate electrodes of a first composition, and sidewall spacers along laterally opposed sides of those gate electrodes, removing the gate electrodes of the first composition, and replacing those gate electrodes with a gate electrode structure having at least two layers of metal. In a further aspect of the present invention, complementary metal oxide semiconductor integrated circuits are fabricated by replacing n-channel transistor gate electrodes with gate electrodes having at least a first metal and a second metal, and further replacing the p-channel transistor gate electrodes with gate electrodes having a third metal and a fourth metal. The first and second metal combination includes, but is not limited to, TiN and Al. The third and fourth metal combination includes, but is not limited to, TaN and Ni; TaN and Pd; and TaN and Pt.
    Type: Grant
    Filed: October 6, 2003
    Date of Patent: April 12, 2005
    Assignee: Intel Corporation
    Inventors: Jun-Fei Zheng, Chunlin Liang
  • Patent number: 6878579
    Abstract: An aspect of the present invention includes a first conductive type semiconductor region; a gate electrode formed on the first conductive type semiconductor region; a channel region formed immediately below the gate electrode in the first conductive type semiconductor region; and a second conductive type first diffusion layer constituting source/drain regions formed at opposite sides of the channel region in the first conductive type semiconductor region, the gate electrode being formed of polycrystalline silicon-germanium, in which a germanium concentration is continuously increased from a drain region side to a source region side, and an impurity concentration immediately below the gate electrode in the first conductive type semiconductor region being continuously increased from the source region side to the drain region side in accordance with the germanium concentration in the gate electrode.
    Type: Grant
    Filed: August 13, 2004
    Date of Patent: April 12, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuya Ohuchi, Hironobu Fukui
  • Patent number: 6873020
    Abstract: Integrated circuit electrodes include an alloy of a first metal and a second metal having lower work function than the first metal. The second metal also may have higher oxygen affinity than the first metal. The first metal may be Ru, Ir, Os, Re and alloys thereof, and the second metal may be Ta, Nb, Al, Hf, Zr, La and alloys thereof. Both NMOS and the PMOS devices can include gate electrodes of an alloy of the first metal and the second metal having lower work function than the first metal. The PMOS gate electrode may have a higher percentage of the first metal relative to the second metal than the NMOS gate electrode. Thus, a common material system may be used for gate electrodes for both NMOS and PMOS devices.
    Type: Grant
    Filed: February 22, 2002
    Date of Patent: March 29, 2005
    Assignee: North Carolina State University
    Inventors: Veena Misra, Huicai Zhong, ShinNam Hong
  • Patent number: 6870224
    Abstract: When polycrystalline silicon germanium film is used for gate electrodes in a MOS transistor apparatus, there have been problems of reduced reliability in the gate insulating film, due to stress in the silicon germanium grains. Therefore, a polysilicon germanium film is formed, after forming silicon fine particles of particle size 10 nm or less on an oxide film. As a result, it is possible to achieve a high-speed MOS transistor apparatus using an ultra-thin oxide film having a film thickness of 1.5 nm or less, wherein the Ge concentration of the polycrystalline silicon germanium at its interface with the oxide film is uniform, thereby reducing the stress in the film, and improving the reliability of the gate electrode.
    Type: Grant
    Filed: August 15, 2003
    Date of Patent: March 22, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Naoki Kanda, Arito Ogawa, Eisuke Nishitani, Miwako Nakahara, Tadanori Yoshida, Kiyoshi Ogata
  • Patent number: 6861712
    Abstract: A stacked metal gate MOSFET and fabrication method are provided. The method comprises: forming a gate oxide layer overlying a channel region; forming a first metal layer having a first thickness overlying the gate oxide layer; forming a second metal layer having a second thickness overlying the first metal layer; and, establishing a gate work function in response to the combination of the first and second thicknesses. In one example, the first metal layer has a thickness of less than about 1.5 nanometers (nm) the second metal layer has a thickness greater than about 10 nm. Then, establishing a gate work function includes establishing a gate work function substantially in response to the second metal second thickness. Alternately, the first metal thickness is greater than about 20 nm. Then, the gate work function is established substantially in response to the first metal thickness.
    Type: Grant
    Filed: January 15, 2003
    Date of Patent: March 1, 2005
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: Wei Gao, Yoshi Ono
  • Patent number: 6858906
    Abstract: Floating trap non-volatile memory devices and methods are provided. The memory devices include a semiconductor substrate and an adjacent gate electrode. Between the substrate and the gate electrode may be a tunneling insulating layer having a first dielectric constant, a blocking insulating layer having a second dielectric constant that is greater than the first dielectric constant, and a charge storage layer.
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: February 22, 2005
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Chang-Hyun Lee, Jung-Dal Choi, Byoung-Woo Ye
  • Patent number: 6858908
    Abstract: A method of forming a first and second transistor. The method provides a semiconductor surface (20). The method also forms a gate dielectric (30) adjacent the semiconductor surface. Further, the method forms a first transistor gate electrode (902) comprising a metal portion (402) in a fixed relationship with respect to the gate dielectric. Still further, the method forms a second transistor gate electrode (901) comprising a silicide (701) of the metal portion in a fixed relationship with respect to the gate dielectric.
    Type: Grant
    Filed: August 13, 2003
    Date of Patent: February 22, 2005
    Assignee: Texas Instruments Incorporated
    Inventors: Antonio L. P. Rotondaro, Mark R. Visokay
  • Patent number: 6855989
    Abstract: A fin field effect transistor includes a fin, a source region, a drain region, a first gate electrode and a second gate electrode. The fin includes a channel. The source region is formed adjacent a first end of the fin and the drain region is formed adjacent a second end of the fin. The first gate electrode includes a first layer of metal material formed adjacent the fin. The second gate electrode includes a second layer of metal material formed adjacent the first layer. The first layer of metal material has a different work function than the second layer of metal material. The second layer of metal material selectively diffuses into the first layer of metal material via metal interdiffusion.
    Type: Grant
    Filed: October 1, 2003
    Date of Patent: February 15, 2005
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Haihong Wang, Shibly S. Ahmed, Ming-Ren Lin, Bin Yu
  • Patent number: 6853020
    Abstract: A double-gate semiconductor device includes a substrate, an insulating layer, a fin and two gates. The insulating layer is formed on the substrate and the fin is formed on the insulating layer. A first gate is formed on the insulating layer and is located on one side of the fin. A portion of the first gate includes conductive material doped with an n-type dopant. The second gate is formed on the insulating layer and is located on the opposite side of the fin as the first gate. A portion of the second gate includes conductive material doped with a p-type dopant.
    Type: Grant
    Filed: November 8, 2002
    Date of Patent: February 8, 2005
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Bin Yu, Judy Xilin An
  • Patent number: 6835989
    Abstract: Methods for forming dual-metal gate CMOS transistors are described. An NMOS and a PMOS active area of a semiconductor substrate are separated by isolation regions. A metal layer is deposited over a gate dielectric layer in each active area. Oxygen ions are implanted into the metal layer in one active area to form an implanted metal layer which is oxidized to form a metal oxide layer. Thereafter, the metal layer and the metal oxide layer are patterned to form a metal gate in one active area and a metal oxide gate in the other active area wherein the active area having the gate with the higher work function is the PMOS active area. Alternatively, both gates may be metal oxide gates wherein the oxide concentrations of the two gates differ. Alternatively, a dummy gate may be formed in each of the active areas and covered with a dielectric layer. The dielectric layer is planarized thereby exposing the dummy gates. The dummy gates are removed leaving gate openings to the semiconductor substrate.
    Type: Grant
    Filed: December 16, 2003
    Date of Patent: December 28, 2004
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Wenhe Lin, Mei-Sheng Zhou, Kin Leong Pey, Simon Chooi
  • Patent number: 6831336
    Abstract: A semiconductor device capable of accurately controlling the current value is provided. In a semiconductor integrated circuit having a constant current circuit, the constant current circuit includes a plurality of constant current elements having a gate terminal and a source terminal in common. Branched drain terminals of the constant current element arranged on one end of the gate terminal and the source terminal are arranged to both the gate terminal and the source terminal.
    Type: Grant
    Filed: November 4, 2002
    Date of Patent: December 14, 2004
    Assignee: Seiko Instruments Inc.
    Inventor: Toshiki Ishii
  • Publication number: 20040245578
    Abstract: A method of constructing a dual metal gate CMOS structure that uses an ultra thin aluminum nitride (AINx) buffer layer between the metal gate and gate dielectric during processing for preventing the gate dielectric from being exposed in the metal etching process. After the unwanted gate metal is etched away, the CMOS structure is annealed. During the annealing, the buffer layer is completely consumed through reaction with the metal gate and a new metal alloy is formed, resulting in only a minimal increase in the equivalent oxide thickness. The buffer layer and gate metals play a key role in determining the work functions of the metal/dielectric interface, since the work functions of the original gate metals are modified as a result of the annealing process.
    Type: Application
    Filed: April 16, 2004
    Publication date: December 9, 2004
    Inventors: Chang Seo Park, Byung Jin Cho, Narayanan Balasubramanian
  • Patent number: 6821874
    Abstract: An electrode and/or wiring having a polycide structure is formed with voids V therein at the preparing stage as shown in FIG. 3. If the scale down and lowering of resistance of the electrode and/or wiring further proceed in future, the influence of the voids becomes obvious to lower yields. According to the present invention, a method for depositing a tungsten silicide film is characterized in that when a tungsten silicide layer is formed on a polysilicon layer, a phosphorus atom containing gas is added to a reactive gas at least in the initial stage that the tungsten silicide layer is formed, and the amount of the added phosphorus atom containing gas is set to be in the range of from 0.2 vol. % to 0.45 vol. %.
    Type: Grant
    Filed: January 11, 2001
    Date of Patent: November 23, 2004
    Assignee: Tokyo Electron Limited
    Inventors: Masahiko Matsudo, Kenji Suzuki, Kazuya Okubo
  • Publication number: 20040222474
    Abstract: A method for making a semiconductor device is described. That method comprises forming a dielectric layer on a substrate, and forming an impurity containing metal layer on the dielectric layer. A metal gate electrode is then formed from the impurity containing metal layer. Also described is a semiconductor device that comprises a metal gate electrode that is formed on a dielectric layer, which is formed on a substrate. The metal gate electrode includes a sufficient amount of an impurity to shift the workfunction of the metal gate electrode by at least about 0.1 eV.
    Type: Application
    Filed: May 6, 2003
    Publication date: November 11, 2004
    Inventors: Robert Chau, Mark Doczy, Markus Kuhn
  • Publication number: 20040207026
    Abstract: The present invention includes a technique for making a dual voltage integrated circuit device. A gate dielectric layer is formed on a semiconductor substrate and a gate material layer is formed on the dielectric layer. A first region of the gate material layer is doped to a first nonzero level and a second region of the gate material level is doped to a second nonzero level greater than the first level. A first field effect transistor is defined that has a first gate formed from the first region. Also, a second field effect transistor is defined that has a second gate formed from the second region. The first transistor is operable at a gate threshold voltage greater than the second transistor in accordance with a difference between the first level and the second level.
    Type: Application
    Filed: April 29, 2004
    Publication date: October 21, 2004
    Inventors: Xi-Wei Lin, Gwo-Chung Tai
  • Patent number: 6798028
    Abstract: A transistor formed on a substrate comprises a gate electrode having a lateral extension at the foot of the gate electrode that is less than the average lateral extension of the gate electrode. The increased cross-section of the gate electrode compared to the rectangular cross-sectional shape of a prior art device provides for a significantly reduced gate resistance while the effective gate length, i.e., the lateral extension of the gate electrode at its foot, may be scaled down to a size of 100 nm and beyond. Moreover, a method for forming the field effect transistor described above is disclosed.
    Type: Grant
    Filed: May 2, 2001
    Date of Patent: September 28, 2004
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Manfred Horstmann, Rolf Stephan, Karsten Wieczorek, Stephan Kruegel
  • Publication number: 20040183143
    Abstract: A gate electrode of an n-type MIS transistor includes a first metal-containing film, which is formed in contact with a gate insulation film and has a Fermi level on a conductive band side from a substantial center of a band gap of a semiconductor substrate, and a second metal-containing film formed on the first metal-containing film and having a lower resistance than the first metal-containing film. A gate electrode of a p-type MIS transistor includes a conductive coating film, which is formed in contact with the gate insulation film and has a Fermi level on a valence band side from a substantial center of the band gap of the semiconductor substrate, and the second metal-containing film formed on the conductive coating film and having a lower resistance than the conductive coating film.
    Type: Application
    Filed: March 30, 2004
    Publication date: September 23, 2004
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Kouji Matsuo
  • Patent number: 6791106
    Abstract: An aspect of the present invention includes a first conductive type semiconductor region; a gate electrode formed on the first conductive type semiconductor region; a channel region formed immediately below the gate electrode in the first conductive type semiconductor region; and a second conductive type first diffusion layer constituting source/drain regions formed at opposite sides of the channel region in the first conductive type semiconductor region, the gate electrode being formed of polycrystalline silicon-germanium, in which a germanium concentration is continuously increased from a drain region side to a source region side, and an impurity concentration immediately below the gate electrode in the first conductive type semiconductor region being continuously increased from the source region side to the drain region side in accordance with the germanium concentration in the gate electrode.
    Type: Grant
    Filed: April 23, 2003
    Date of Patent: September 14, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuya Ohuchi, Hironobu Fukui
  • Patent number: 6790731
    Abstract: A method for creating insulated gate field effect transistors having gate electrodes with at least two layers of materials to provide gate electrode work function values that are similar to those of doped polysilicon, to eliminate the poly depletion effect, and to substantially prevent impurity diffusion into the gate dielectric. Depositing bi-layer stacks of relatively thick Al and thin TiN for n-channel FETs and bi-layer stacks of relatively thick Pd and thin TiN, or relatively thick Pd and thin TaN for p-channel FETs is disclosed. Varying the thickness of the thin TiN or TaN layers between a first and second critical thickness may be used to modulate the work function of the gate electrode and thereby obtain the desired trade-off between channel doping and drive currents in FETs.
    Type: Grant
    Filed: February 6, 2002
    Date of Patent: September 14, 2004
    Assignee: Intel Corporation
    Inventors: Jun-Fei Zheng, Brian Doyle, Gang Bai, Chunlin Liang
  • Publication number: 20040164362
    Abstract: A method, and corresponding transistor structure are provided for protecting the gate electrode from an underlying gate insulator. The method comprises: forming a gate insulator overlying a channel region; forming a first metal barrier overlying the gate insulator, having a thickness of less than 5 nanometers (nm); forming a second metal gate electrode overlying the first metal barrier, having a thickness of greater than 10 nm; and, establishing a gate electrode work function exclusively responsive to the second metal. The second metal gate electrode can be one of the following materials: elementary metals such as p+ poly, n+ poly. Ta, W, Re, RuO2, Pt, Ti, Hf, Zr, Cu, V, Ir, Ni, Mn, Co, NbO, Pd, Mo, TaSiN, and Nb, and binary metals such as WN, TaN, and TiN. The first metal barrier can be a binary metal, such as TaN, TiN, or WN.
    Type: Application
    Filed: February 23, 2004
    Publication date: August 26, 2004
    Inventors: John F. Conley, Yoshi Ono, Wei Gao
  • Patent number: 6773978
    Abstract: Methods are disclosed for manufacturing semiconductor devices with silicide metal gates, wherein a single-step anneal is used to react a metal such as cobalt or nickel with substantially all of a polysilicon gate structure while source/drain regions are covered. A second phase conductive metal silicide is formed consuming substantially all of the polysilicon and providing a substantially uniform work function at the silicide/gate oxide interface.
    Type: Grant
    Filed: August 28, 2002
    Date of Patent: August 10, 2004
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Paul Raymond Besser, Eric Paton, James Pan
  • Patent number: 6770944
    Abstract: A semiconductor device has a first semiconductor region formed in a semiconductor substrate and having a first conductivity type due to first-conductivity-type active impurities contained in the first semiconductor region, and a second semiconductor region formed between the first semiconductor region and the surface of the semiconductor substrate and having a second conductivity type due to second-conductivity-type active impurities contained in the second semiconductor region. The second semiconductor region contains first-conductivity-type active impurities whose concentration is zero or smaller than a quarter of a concentration of the second-conductivity-type active impurities contained in the second semiconductor region. An insulating film and a conductor are formed on the second semiconductor region. Third and fourth semiconductor regions of the second conductivity type are formed at the semiconductor surface in contact with the side faces of the second semiconductor region.
    Type: Grant
    Filed: November 26, 2002
    Date of Patent: August 3, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazumi Nishinohara, Yasushi Akasaka, Kyoichi Suguro
  • Publication number: 20040140513
    Abstract: According to one aspect, a CMOS device includes a PMOS transistor and an NMOS transistor, where each transistor includes a source, a drain, a channel region between the source and the drain, and a gate separated from the channel region by a gate insulator. The gate of the PMOS transistor includes a metallic conductor formed by atomic layer deposition and engineered to provide the gate with a first composition having a first work function. The gate of the NMOS transistor includes a metallic conductor formed by atomic layer deposition and engineered to provide the gate with a second composition having a second work function such that the NMOS transistor and the PMOS transistor have threshold voltages of approximately the same magnitude. At least one of the gates includes a ternary metal conductor formed by atomic layer deposition.
    Type: Application
    Filed: January 9, 2004
    Publication date: July 22, 2004
    Applicant: Micron Technology, Inc.
    Inventors: Leonard Forbes, Kie Y. Ahn
  • Patent number: 6762469
    Abstract: High performance (surface channel) CMOS devices with a mid-gap work function metal gate are disclosed wherein an epitaxial layer is used for a threshold voltage Vt adjust/decrease for the PFET area, for large Vt reductions (˜500 mV), as are required by CMOS devices with a mid-gap metal gate. The present invention provides counter doping using an in situ B doped epitaxial layer or a B and C co-doped epitaxial layer, wherein the C co-doping provides an additional degree of freedom to reduce the diffusion of B (also during subsequent activation thermal cycles) to maintain a shallow B profile, which is critical to provide a surface channel CMOS device with a mid-gap metal gate while maintaining good short channel effects. The B diffusion profiles are satisfactorily shallow, sharp and have a high B concentration for devices with mid-gap metal gates, to provide and maintain a thin, highly doped B layer under the gate oxide.
    Type: Grant
    Filed: April 19, 2002
    Date of Patent: July 13, 2004
    Assignee: International Business Machines Corporation
    Inventors: Anda C. Mocuta, Meikei Ieong, Ricky S. Amos, Diane C. Boyd, Dan M. Mocuta, Huajie Chen
  • Patent number: 6762468
    Abstract: An aspect of the present invention includes a first conductive type semiconductor region formed in a semiconductor substrate, a gate electrode formed on the first conductive type semiconductor region, a channel region formed immediately below the gate electrode in the first conductive type semiconductor region, and a second conductive type first diffusion layers constituting source/drain regions formed at opposite sides of the channel region in the first conductive type semiconductor region, the gate electrode being formed of polycrystalline silicon-germanium, in which the germanium concentration of at least one of the source side and the drain side is higher than that of the central portion.
    Type: Grant
    Filed: February 28, 2002
    Date of Patent: July 13, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Kazuya Ohuchi
  • Publication number: 20040129988
    Abstract: The present invention pertains to formation of a PMOS transistor wherein a layer of silicon or SiGe inhibits p-type dopant from entering into an underlying gate dielectric layer. The p-type dopant can be added to a gate electrode material that overlies the silicon or SiGe layer and can diffuse down toward the silicon or SiGe layer. The layer of silicon or SiGe may be formed to a thickness of about 5 to 120 nanometers and doped with a dopant, such as indium (In), for example, to deter the p-type dopant from passing through the silicon or SiGe layer. The dopant may have a peak concentration within the layer of silicon or SiGe near the interface of the silicon or SiGe layer with the underlying layer of gate dielectric material. Allowing the gate electrode to be doped with the p-type dopant (e.g., boron) facilitates forming the transistor with an associated work function having a desired value (e.g., coincident with a Fermi level of about 4.8 to about 5.6 electron volts).
    Type: Application
    Filed: January 3, 2003
    Publication date: July 8, 2004
    Inventors: Antonio Luis Pacheco Rotondaro, James J. Chambers, Amitabh Jain