Differential Oxidation And Etching Patents (Class 438/911)
  • Patent number: 8883624
    Abstract: Memory cells including embedded SONOS based non-volatile memory (NVM) and MOS transistors and methods of forming the same are described. Generally, the method includes: forming a gate stack of a NVM transistor in a NVM region of a substrate including the NVM region and a plurality of MOS regions; and depositing a high-k dielectric material over the gate stack of the NVM transistor and the plurality of MOS regions to concurrently form a blocking dielectric comprising the high-k dielectric material in the gate stack of the NVM transistor and high-k gate dielectrics in the plurality of MOS regions. In one embodiment, a first metal layer is deposited over the high-k dielectric material and patterned to concurrently form a metal gate over the gate stack of the NVM transistor, and a metal gate of a field effect transistor in one of the MOS regions.
    Type: Grant
    Filed: March 28, 2014
    Date of Patent: November 11, 2014
    Assignee: Cypress Semiconductor Corporation
    Inventor: Krishnaswamy Ramkumar
  • Patent number: 8557612
    Abstract: A method to determine minimum etch mask dosage or thickness as a function of etch depth or maximum etch depth as a function of etch mask implantation dosage or thickness, for fabricating structures in or on a substrate through etch masking via addition or removal of a masking material and subsequent etching.
    Type: Grant
    Filed: June 25, 2010
    Date of Patent: October 15, 2013
    Assignee: California Institute of Technology
    Inventors: Michael David Henry, Michael Shearn, Axel Scherer
  • Patent number: 8435861
    Abstract: A method of manufacturing a semiconductor device includes oxidizing a surface of a semiconductor substrate to form a first insulating film covering a first area, a second area, and a third area of the semiconductor substrate; removing the portions of the first insulating film lying on the first area and the second area; oxidizing the surface of the semiconductor substrate to form a second insulating film covering the first area and the second area and further oxidizing the third area covered with the first insulating film; and removing the portion of the second insulating film lying on from the second area and the portion of the first insulating film lying on the third area.
    Type: Grant
    Filed: December 1, 2010
    Date of Patent: May 7, 2013
    Assignee: Fujitsu Semiconductor Limited
    Inventors: Junichi Ariyoshi, Kazutaka Yoshizawa
  • Patent number: 8163626
    Abstract: Embodiments described herein generally relate to flash memory devices and methods for manufacturing flash memory devices. In one embodiment, a method for selective removal of nitrogen from the nitrided areas of a substrate is provided. The method comprises positioning a substrate comprising a material layer disposed adjacent to an oxide containing layer in a processing chamber, exposing the substrate to a nitridation process to incorporate nitrogen onto the material layer and the exposed areas of the oxide containing layer, and exposing the nitrided material layer and the nitrided areas of the oxide containing layer to a gas mixture comprising a quantity of a hydrogen containing gas and a quantity of an oxygen containing gas to selectively remove nitrogen from the nitrided areas of the oxide containing layer relative to the nitrided material layer using a radical oxidation process.
    Type: Grant
    Filed: June 15, 2010
    Date of Patent: April 24, 2012
    Assignee: Applied Materials, Inc.
    Inventors: Johanes Swenburg, David Chu, Theresa Kramer Guarini, Yonah Cho, Udayan Ganguly, Lucien Date
  • Patent number: 7972933
    Abstract: Methods of forming semiconductor devices are provided herein. In some embodiments, a method of forming a semiconductor device may include providing a substrate having an oxide surface and a silicon surface; forming a nitrogen-containing layer on exposed portions of both the oxide and silicon surfaces; and oxidizing the nitrogen-containing layer to selectively remove the nitrogen-containing layer from atop the oxide surface. In some embodiments, an oxide layer is formed atop a remaining portion of the nitrogen-containing layer formed on the silicon feature. In some embodiments, the oxide surface is an exposed surface of a shallow trench isolate region (STI) disposed adjacent to one or more floating gates of a semiconductor device. In some embodiments, the silicon surface is an exposed surface of a silicon or polysilicon floating gate of a semiconductor device.
    Type: Grant
    Filed: March 29, 2010
    Date of Patent: July 5, 2011
    Assignee: Applied Materials, Inc.
    Inventors: Christopher S. Olsen, Johanes Swenberg, Udayan Ganguly, Theresa Kramer Guarini, Yonah Cho
  • Patent number: 7915176
    Abstract: A method for manufacturing a device including a field of micrometric tips, including forming a polycrystalline layer on a support; performing an anisotropic plasma etching of all or part of the polycrystalline layer by using a gas mixture including chlorine and helium, whereby tips are formed at the surface of the polycrystalline layer.
    Type: Grant
    Filed: June 30, 2006
    Date of Patent: March 29, 2011
    Assignee: STMicroelectronics Crolles 2 SAS
    Inventors: Olivier De Sagazan, Matthieu Denoual
  • Patent number: 7902021
    Abstract: A method for making a semiconductor device is disclosed. In accordance with the method, a semiconductor structure is provided which includes (a) a substrate (203), (b) first and second gate electrodes (219) disposed over the substrate, each of the first and second gate electrodes having first and second sidewalls, and (c) first (223) and second (225) sets of spacer structures disposed adjacent to the first and second gate electrodes, respectively. A first layer of photoresist (231) is then disposed over the structure such that the first set of spacer structures is exposed and the second set of spacer structures is covered, after which the first set of spacer structures is partially etched.
    Type: Grant
    Filed: February 28, 2006
    Date of Patent: March 8, 2011
    Assignee: Freescale Semiconductor, Inc.
    Inventor: Anadi Srivastava
  • Patent number: 7786016
    Abstract: A method of substantially uniformly removing silicon oxide is disclosed. The silicon oxide to be removed includes at least one cavity therein or more than one density or strain therein. The silicon oxide having at least one cavity or more than one density or strain is exposed to a gaseous mixture of NH3 and HF and heated, to substantially uniformly remove the silicon oxide. A method of removing an exposed sacrificial layer without substantially removing exposed isolation regions using the gaseous mixture of NH3 and HF and heat is also disclosed, as is an intermediate semiconductor device structure that includes a semiconductor substrate, a sacrificial layer overlying the semiconductor substrate, a diffusion barrier overlying the sacrificial layer, and exposed isolation regions.
    Type: Grant
    Filed: January 11, 2007
    Date of Patent: August 31, 2010
    Assignee: Micron Technology, Inc.
    Inventors: Nishant Sinha, Gurtej S. Sandhu, Joseph N. Greeley
  • Patent number: 7687370
    Abstract: A method for forming a semiconductor isolation trench includes forming a pad oxide layer over a substrate and forming a barrier layer over the substrate. A masking layer is formed over the barrier layer and is patterned to form at least one opening in the masking layer. At least a part of the barrier layer and at least a part of the pad oxide layer are etched through the at least one opening resulting in a trench pad oxide layer. Etching of the trench pad oxide layer stops substantially at a top surface of the substrate within the isolation trench. An oxide layer is grown by diffusion on at least the top surface of the substrate corresponding to the at least one isolation trench. The method further includes etching the oxide layer and at least a portion of the substrate to form at least one isolation trench opening.
    Type: Grant
    Filed: January 27, 2006
    Date of Patent: March 30, 2010
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Toni D. Van Gompel, John J. Hackenberg, Rode R. Mora, Suresh Venkatesan
  • Patent number: 7687353
    Abstract: A method of performing ion implantation method for a high-voltage device. The method includes defining a logic region and a high-voltage region in a semiconductor substrate, forming a first gate insulation layer on the semiconductor substrate in the logic region and a second gate insulation layer on the semiconductor substrate in the high-voltage region, the second gate insulation layer being thicker than the first gate insulation layer, forming a hollow region in the logic region and a source region in the high-voltage region by implanting first conductive impurities into the logic region and source regions of the semiconductor substrate, and forming a second conductive impurity layer in the logic region by implanting second conductive impurities logic region of the into the semiconductor substrate.
    Type: Grant
    Filed: November 30, 2007
    Date of Patent: March 30, 2010
    Assignee: Dongbu Hitek Co., Ltd.
    Inventor: Duck Ki Jang
  • Patent number: 7425480
    Abstract: A method of manufacturing a MOS transistor incorporating a silicon oxide film serving as a gate insulating film and containing nitrogen and a polycrystalline silicon film serving as a gate electrode and containing a dopant and arranged such that the gate electrode is formed on the gate electrode insulating film, and an oxidation process using ozone is performed to sufficiently round the shape of the lower edge of the gate electrode.
    Type: Grant
    Filed: April 23, 2007
    Date of Patent: September 16, 2008
    Assignee: Kabushiki Kaisha Tohisba
    Inventors: Yoshio Ozawa, Yasumasa Suizu, Yoshitaka Tsunashima
  • Patent number: 7303946
    Abstract: A method of manufacturing a MOS transistor incorporating a silicon oxide film serving as a gate insulating film and containing nitrogen and a polycrystalline silicon film serving as a gate electrode and containing a dopant and arranged such that the gate electrode is formed on the gate electrode insulating film, and an oxidation process using ozone is performed to sufficiently round the shape of the lower edge of the gate electrode.
    Type: Grant
    Filed: April 27, 2000
    Date of Patent: December 4, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshio Ozawa, Yasumasa Suizu, Yoshitaka Tsunashima
  • Patent number: 7208325
    Abstract: A low-k dielectric layer having a composition of silicon, oxygen and carbon is removed from a wafer. The low-k dielectric layer is removed by exposing a surface of the low-k dielectric layer to an oxygen-containing gas to oxidized the surface. The oxidized surface is immersed in an etching solution having HF and H2SO4 to etch the low-k dielectric layer. The etched surface is exposed to at least one of (i) an etching solution having H2SO4 and H2O2, and (ii) an RF or microwave energized oxygen-containing gas, to remove the low-k dielectric layer from the wafer.
    Type: Grant
    Filed: January 18, 2005
    Date of Patent: April 24, 2007
    Assignee: Applied Materials, Inc.
    Inventors: Hong Wang, Krishna Vepa, Paul V. Miller
  • Patent number: 6890832
    Abstract: A radiation-hardened STI process includes implanting a partially formed wafer with a fairly large dose (1013 to 1017 ions/cm2) of a large atom group III element, such as B, Al, Ga or In at an energy between about 30 and 500 keV. The implant is followed by an implant of a large group V element, such as P, As, Sb, or Bi using similar doses and energies to the group III element. The group V element compensates the group III element. The combination of the two large atoms decreases the diffusivity of small atoms, such as B, in the implanted areas. Furthermore, the combination of the group III and group V elements in roughly equal proportions creates recombination sites and electron traps in the field oxide, resulting in a radiation hardened semiconductor device.
    Type: Grant
    Filed: November 12, 2002
    Date of Patent: May 10, 2005
    Assignee: Aeroflex UTMC Microelectronic Systems, Inc.
    Inventors: David B. Kerwin, Bradley J Larsen
  • Patent number: 6844225
    Abstract: A self-aligned oxide mask is formed utilizing differential oxidation rates of different materials. The self-aligned oxide mask is formed on a CVD grown base NPN base layer which compromises single crystal Si (or Si/SiGe) at active area and polycrystal Si (or Si/SiGe) on the field. The self-aligned mask is fabricated by taking advantage of the fact that poly Si (or Si/SiGe) oxidizes faster than single crystal Si (or Si/SiGe). An oxide film is formed over both the poly Si (or Si/siGe) and the single crystal Si (or Si/siGe) by using an thermal oxidation process to form a thick oxidation layer over the poly Si (or Si/siGe) and a thin oxidation layer over the single crystal Si (or Si/siGe), followed by a controlled oxide etch to remove the thin oxidation layer over the single crystal Si (or Si/siGe) while leaving the self-aligned oxide mask layer over the poly Si (or Si/siGe). A raised extrinsic base is then formed following the self-aligned mask formation.
    Type: Grant
    Filed: January 15, 2003
    Date of Patent: January 18, 2005
    Assignee: International Business Machines Corporation
    Inventors: Huajie Chen, Kathryn T. Schonenberg, Gregory G. Freeman, Andreas D. Stricker, Jae-Sung Rieh
  • Patent number: 6784115
    Abstract: Improved methods for fabricating semiconductor integrated circuit devices, in particular flash EEPROM devices. According to an embodiment, the present invention provides a method of forming a semiconductor device having a gate oxide layer (160) that is thin in some regions, such as the cell region, and thicker in other regions (165), such as the periphery region. The method simultaneously provides a gate oxide layer with two or more thicknesses without the thickness control problems of prior art methods that use contaminant-containing photoresist with an etching step. According to a specific embodiment of the present invention, the gate oxide has a first thickness that is sufficiently thin to provide high driving capability for the semiconductor ROM device, and a second thickness that is sufficiently thick to provide high voltage reliability of the semiconductor ROM device.
    Type: Grant
    Filed: December 18, 1998
    Date of Patent: August 31, 2004
    Assignee: Mosel Vitelic, Inc.
    Inventors: Cheng-Tsung Ni, Jacson Liu, Chih-Sheng Chang, Hudy-Jong Wu
  • Patent number: 6777333
    Abstract: A method for fabricating a semiconductor device includes the steps of: forming an insulating film on a conductive pattern formed on a substrate; forming a resist pattern on the insulating film; performing etching to the insulating film using the resist pattern as a mask to form in the insulating film an opening at which part of the surface of the conductive pattern is exposed; forming an antioxidant layer on the part of surface of the conductive pattern exposed while removing the resist pattern; and depositing a conductive film on the conductive pattern from which the antioxidant layer has been removed.
    Type: Grant
    Filed: August 27, 2003
    Date of Patent: August 17, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Masahiro Joei
  • Patent number: 6759263
    Abstract: A method of patterning a layer of magnetic material to form isolated magnetic regions. The method forms a mask on a film stack comprising a layer of magnetic material such the protected and unprotected regions are defined. The unprotected regions are oxidized to form isolated magnetic regions.
    Type: Grant
    Filed: August 29, 2002
    Date of Patent: July 6, 2004
    Inventors: Chentsau Ying, Xiaoyi Chen, Padmapani C. Nallan, Ajay Kumar
  • Patent number: 6610211
    Abstract: The invention encompasses methods of processing internal surfaces of a chemical vapor deposition reactor. In one implementation, material is deposited over internal surfaces of a chemical vapor deposition reactor while processing semiconductor substrates therein. The deposited material is treated with atomic oxygen. After the treating, at least some of the deposited material is etched from the reactor internal surfaces. In one embodiment, first etching is conducted of some of the deposited material from the reactor internal surfaces. After the first etching, remaining deposited material is treated with atomic oxygen. After the treating, second etching is conducted of at least some of the remaining deposited material from the reactor internal surfaces. In one embodiment, the deposited material is first treated with atomic oxygen. After the first treating, first etching is conducted of some of the deposited material from the reactor internal surfaces.
    Type: Grant
    Filed: March 1, 2000
    Date of Patent: August 26, 2003
    Assignee: Micron Technology, Inc.
    Inventors: F. Daniel Gealy, Husam N. Al-Shareef, Scott Jeffrey DeBoer
  • Patent number: 6555484
    Abstract: Two different regions of a semiconductor substrate are implanted with dopants/ions. The implantation may occur though a sacrificial oxide layer disposed over the substrate. Following implantation in one or both regions, the substrate may be annealed and the sacrificial oxide layer removed. An oxide layer is then grown over the implanted regions of the substrate. For some embodiments, the substrate may be implanted with arsenic and/or with phosphorus. Further, the anneal may be performed for approximately 30 to 120 minutes at a temperature between approximately 900° C. and 950° C.
    Type: Grant
    Filed: June 19, 1997
    Date of Patent: April 29, 2003
    Assignee: Cypress Semiconductor Corp.
    Inventors: Krishnaswamy Ramkumar, Hanna Bamnolker
  • Publication number: 20030040192
    Abstract: After forming a resist pattern on an insulating film deposited on a semiconductor substrate, the insulating film is subjected to plasma etching using an etching gas including carbon and fluorine with the resist pattern used as a mask. A polymer film having been deposited on the resist pattern during the plasma etching is subjected to a first stage of ashing with a relatively low chamber pressure and relatively low plasma generation power by using an oxygen gas or a gas including oxygen as a principal constituent. A residual polymer present on the insulating film in completing the first stage of the ashing is subjected to a second stage of the ashing with a relatively high chamber pressure and relatively high plasma generation power by using an oxygen gas or a gas including oxygen as a principal constituent.
    Type: Application
    Filed: April 24, 2002
    Publication date: February 27, 2003
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventor: Kenshi Kanegae
  • Patent number: 6455440
    Abstract: In accordance with the present invention, a method for preventing polysilicon stringers in memory devices is disclosed. The key aspect of the present invention is the formation of a floating gate structure with multi-level oxidation rates the lower portion of the floating gate structure the higher oxidation rate, such as a floating gate structure with two polysilicon layers of different doping concentration or crystallinity the lower polysilicon layer the higher doping concentration, or the lower polysilicon layer the higher crystallinity. Therefore, in a later oxidation process a desired profile of the floating gate structure for etch process defining word lines is formed, that is from lower portion to higher portion of the floating gate structure an increasing width profile is formed. The width of the upper portion of the floating gate structure is bigger than that of the lower portion of the floating gate structure.
    Type: Grant
    Filed: July 13, 2001
    Date of Patent: September 24, 2002
    Assignee: Macronix International Co., Ltd.
    Inventor: Pei-Ren Jeng
  • Patent number: 6368986
    Abstract: A process for selectively depositing a silicon oxide layer onto silicon substrates of different conductivity types is disclosed. The silicon oxide layer is formed by the ozone decomposition of TEOS at relatively low temperatures and relatively high pressures. Use of the process to produce layers, spacers, memory units, and gates is also disclosed, as well as the structures so produced.
    Type: Grant
    Filed: August 31, 2000
    Date of Patent: April 9, 2002
    Assignee: Micron Technology, Inc.
    Inventors: William Budge, Gurtej S. Sandhu, Christopher W. Hill
  • Patent number: 6344416
    Abstract: Methods and apparatuses are disclosed that can introduce deliberate semiconductor film variation during semiconductor manufacturing to compensate for radial processing differences, to determine optimal device characteristics, or produce small production runs. The present invention radially varies the thickness and/or composition of a semiconductor film to compensate for a known radial variation in the semiconductor film that is caused by performing a subsequent semiconductor processing step on the semiconductor film. Additionally, methods and apparatuses are disclosed that can introduce deliberate semiconductor film variations to determine optimal device characteristics or produce small production runs. Introducing semiconductor film variations, such as thickness variations and/or composition variations, allow different devices to be made. A number of devices may be made having variations in semiconductor film.
    Type: Grant
    Filed: March 10, 2000
    Date of Patent: February 5, 2002
    Assignee: International Business Machines Corporation
    Inventors: Toshiharu Furukawa, Mark C. Hakey, Steven J. Holmes, David V. Horak
  • Patent number: 6335288
    Abstract: A method and apparatus are disclosed for depositing a dielectric film in a gap having an aspect ratio at least as large as 6:1. By cycling the gas chemistry of a high-density-plasma chemical-vapor-deposition system between deposition and etching conditions, the gap may be substantially 100% filled. Such filling is achieved by adjusting the flow rates of the precursor gases such that the deposition to sputtering ratio during the deposition phases is within certain predetermined limits.
    Type: Grant
    Filed: August 24, 2000
    Date of Patent: January 1, 2002
    Assignee: Applied Materials, Inc.
    Inventors: Michael Kwan, Eric Liu
  • Patent number: 6239478
    Abstract: The MOS transistor has field plates and a subarea of the gate formed from the same polysilicon layer. A gate oxide lying underneath them is produced at the beginning of the fabrication process and it therefore exhibits particularly high quality. The polysilicon in the active area is raised to the same level as the adjoining field oxide areas, resulting in a planar topology.
    Type: Grant
    Filed: June 10, 1998
    Date of Patent: May 29, 2001
    Assignee: Infineon Technologies AG
    Inventors: Martin Kerber, Udo Schwalke
  • Patent number: 6225167
    Abstract: A method is disclosed to form a plurality of oxides of different thicknesses with one step oxidation. In a first embodiment, a substrate is provided having a high-voltage cell area and a peripheral low-voltage logic area separated by a trench isolation region. The substrate is first nitrided. Then the nitride layer over the high-voltage area is removed, and the substrate is wet cleaned with HF solution. The substrate surface is next oxidized to form a tunnel oxide of desired thickness over the high-voltage. In a second embodiment, a sacrificial oxide is used over the substrate for patterning the high voltage cell area and the low-voltage logic area. The sacrificial oxide is removed from the low-voltage area and the substrate is nitrided after cleaning with a solution not containing HF, thus forming a nitride layer over the low-voltage area. Then, the sacrificial oxide is removed from the high-voltage area with an HF dip, and tunnel oxide of desired thickness is formed over the same area.
    Type: Grant
    Filed: March 13, 2000
    Date of Patent: May 1, 2001
    Assignee: Taiwan Semiconductor Manufacturing Company
    Inventors: Mo-Chiun Yu, Wei-Ming Chen
  • Patent number: 6211058
    Abstract: A semiconductor device having multiple layers uses different size contacts at different layer in order in order to simply the manufacturing process and the depth of etching required. Contact sizes are selected based on the responsiveness of the material to the etching process. Where a deep etch is required, a larger contact is used. A shallower etch through similar material uses a smaller contact to slow the etching process. As a result, the etches can complete at about the same time. The technique can be employed to etch any number of contacts. An intermediate size contact can be used where the material to be etched results in a slower etching process. A plurality of contact sizes can be used depending on the depths of etching required and the characteristics material to be etched, so that the etching for all the contacts completes at substantially the same time.
    Type: Grant
    Filed: July 15, 1999
    Date of Patent: April 3, 2001
    Assignee: Advanced Micro Devices, Inc.
    Inventors: John Jianshi Wang, Hao Fang
  • Patent number: 6087243
    Abstract: The quality of an ultra thin gate oxide film, particularly at the edges of a shallow trench isolation structure, is improved employing a double sacrificial oxide technique. After trench filling and planarization, the pad oxide layer thickness is increased during trench fill densification in an oxidizing atmosphere. The pad oxide is then removed exposing the substrate surface and trench edges. A second sacrificial oxide is formed consuming part of the substrate surface. The second sacrificial oxide is then removed along with defects in the substrate surface prior to gate oxide and gate electrode formation.
    Type: Grant
    Filed: October 21, 1997
    Date of Patent: July 11, 2000
    Assignee: Advanced Micro Devices, Inc.
    Inventor: Larry Yu Wang
  • Patent number: 6052261
    Abstract: A method for manufacturing a magnetoresistance head of the present invention comprises the steps of forming an organic film on a multilayered film constituting a magnetoresistance device, forming an upper film formed of resist or inorganic film on the organic film, patterning the organic film and the upper film, cutting into edges of the organic film patterns from edges of the upper film patterns inwardly to such an extent that particles of the thin film being formed on the upper film and the multilayered film do not contact to side portions of the organic film patterns.
    Type: Grant
    Filed: June 24, 1996
    Date of Patent: April 18, 2000
    Assignee: Fujitsu Limited
    Inventors: Keiji Watanabe, Koji Nozaki, Miwa Igarashi, Yoko Kuramitsu, Ei Yano, Takahisa Namiki, Hiroshi Shirataki, Keita Ohtsuka, Michiaki Kanamine, Yuji Uehara
  • Patent number: 6043128
    Abstract: A method of fabricating a multi power source semiconductor device handling multi-level voltages, comprises the steps of: forming first gate oxide layers by thermally oxidizing surfaces of the plurality of the active regions of said semiconductor substrate; forming a first mask having a window on a first active region among said plurality of the active regions of said semiconductor substrate; implanting impurity ions for controlling a threshold voltage, into a surface of said first active region through the first mask; removing the first gate oxide layer on the first active region exposed in the window of said first mask; removing said first mask; forming a thin second gate oxide layer on the first active region and a thick third gate oxide layer on a second active region different from the first active region among said plurality of the active regions by further thermally oxidizing the surfaces of the plurality of the active regions; forming on the semiconductor substrate a second mask having a window on the
    Type: Grant
    Filed: February 2, 1998
    Date of Patent: March 28, 2000
    Assignee: Yamaha Corporation
    Inventor: Takayuki Kamiya
  • Patent number: 6015736
    Abstract: A system and method for providing at least one memory cell on a semiconductor is disclosed. The method and system include providing a tunneling barrier on the semiconductor, providing at least one floating gate having a corner, and oxidizing the tunneling barrier, a portion of the semiconductor, and the at least one floating gate. A portion of the at least one floating gate including the corner is disposed above the tunneling barrier. The portion of the semiconductor oxidizes at a first rate and at least the corner of the at least one floating gate oxidizes at a second rate. The second rate is sufficiently higher than the first rate to provide a desired thickness of the tunneling barrier a distance from the corner of the at least one floating gate for a particular rounding of the corner of the at least one floating gate.
    Type: Grant
    Filed: December 19, 1997
    Date of Patent: January 18, 2000
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Scott D. Luning, Mark Randolph
  • Patent number: 5994216
    Abstract: A method for forming a reduced size contact hole over a structure.
    Type: Grant
    Filed: April 23, 1998
    Date of Patent: November 30, 1999
    Assignee: Vanguard International Semiconductor Corporation
    Inventor: Chih-Hsiung Cheng
  • Patent number: 5972757
    Abstract: The present invention relates to a semiconductor device whose through-holes are formed by self-alignment, and a method for fabricating the same. The through-holes formed on the gate electrodes can be formed simultaneously with SACs without complicating the fabrication process. The semiconductor device comprises a semiconductor substrate, a device isolation film defining devices regions on the semiconductor substrate, a pair of diffused layers formed in the device regions, gate electrodes formed through a first insulation film on the semiconductor substrate between the pair of diffused layers, and an etching stopper film covering side walls of the gate electrodes and parts of top surfaces of the gate electrodes which are extended inward by a prescribed distance from peripheral edges thereof. Whereby through-holes of an SAC structure can be formed in a later step, and the through-holes can be formed to expose the gate electrodes without removing the etching stopper film.
    Type: Grant
    Filed: April 21, 1998
    Date of Patent: October 26, 1999
    Assignee: Fujitsu Limited
    Inventor: Taiji Ema
  • Patent number: 5922621
    Abstract: A method for fabricating a quantum semiconductor device includes the steps of forming an etch pit of a triangular pyramid on a {111}A-oriented principal surface of a substrate having zinc blende structure by a dry etching process, and depositing semiconductor layers forming a quantum structure consecutively on the etch pit.
    Type: Grant
    Filed: April 8, 1997
    Date of Patent: July 13, 1999
    Assignee: Fujitsu Limited
    Inventor: Yoshiki Sakuma
  • Patent number: 5824601
    Abstract: A sacrificial oxide etching solution of carboxylic acid and HF having a high etch selectivity for silicon oxide relative to polysilicon, metal, and nitride. The solution is useful in the fabrication of microstructures having integrated electronics on the same chip. A carboxylic acid anhydride can be added to this solution to substantially remove all free water so that the etch selectivity to metal is improved. One specific solution is formed by mixing acetic acid, acetic anhydride, and aqueous HF.
    Type: Grant
    Filed: June 30, 1997
    Date of Patent: October 20, 1998
    Assignee: Motorola, Inc.
    Inventors: Patrick P. H. Dao, Paul William Dryer, Ping-Chang Lue, Michael J. Davison, Terry Andrew Willett, Margaret Leslie Kniffin, Rita Prasad Subrahmanyan
  • Patent number: 5798303
    Abstract: An etching method includes providing a first surface and a second surface with the second surface lying substantially vertical to the first surface. A material is provided over at least a portion of the first and second surface. The material is anisotropically etched from at least the first surface resulting in a blocking material formed over at least a portion of the material on the second surface. The blocking material is removed and the portion of the material formed over the second surface is isotropically etched. The blocking material may be a polymer material, and the removing step may include oxidizing the polymer material.
    Type: Grant
    Filed: September 5, 1996
    Date of Patent: August 25, 1998
    Assignee: Micron Technology, Inc.
    Inventor: Darwin A. Clampitt
  • Patent number: 5654215
    Abstract: In the present invention, a method for fabrication of a non-symmetrical LDD-IGFET is described. In one embodiment, a gate insulator and a gate electrode, such as a polysilicon, are formed over a semiconductor substrate, the gate electrode having a top surface and opposing first and second sidewalls. A first dopant is implanted into the semiconductor substrate to provide a lightly doped drain region substantially aligned with the second sidewall. First and second symmetrical spacers are then formed adjacent the first and second sidewalls, respectively. A second dopant is implanted into the semiconductor substrate after forming the symmetrical spacers to provide a moderately-lightly doped drain region substantially aligned with the outer region of the second symmetrical spacer. After implanting the second dopant, first and second non-symmetrical spacers are formed adjacent the first and second sidewalls, respectively.
    Type: Grant
    Filed: September 13, 1996
    Date of Patent: August 5, 1997
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Mark I. Gardner, Daniel Kadosh, Robert Dawson
  • Patent number: 5628917
    Abstract: A masking process resulting from a modified version of the SCREAM process is used for the fabrication of ultra-high aspect ratio, wafer-free, single crystal silicon movable micromechanical devices and frame structures of large vertical depth and narrow linewidth. The process is single-mask, self-aligned and allows the formation of releasable three-dimensional frame-like objects of arbitrary shape which can be made up to about half the wafer thickness in depth and can be subsequently lifted off the substrate and placed on any other material to be used as a mask or to be integrated with other devices. The process consists of a single lithography step and a repeated sequence of thermal oxidations and reactive ion etchings.
    Type: Grant
    Filed: February 3, 1995
    Date of Patent: May 13, 1997
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Noel C. MacDonald, Ali Jazairy
  • Patent number: 5627099
    Abstract: In a method of manufacturing a semiconductor device, after forming a poly silicon film 54 on a surface of a silicon substrate 51, a silicon nitride film 55 is formed in accordance with a desired pattern and a local oxidation process is carried out to form a field oxide film 56 having a large thickness. Then, after removing the silicon nitride film 55, the poly silicon film 54 is fully converted in to a silicon oxide film 58 and then the thus converted silicon oxide film is removed by wet etching to expose a clean surface of the silicon substrate 51. The poly silicon film does not constitute an oxygen source, so that during the local oxidation, a lateral diffusion of oxygen is prevented and a generation of bird's beak can be suppressed. Further, the poly silicon film serves as a buffer, no stress remains in the surface of the silicon substrate.
    Type: Grant
    Filed: December 7, 1994
    Date of Patent: May 6, 1997
    Assignee: LSI Logic Japan Semiconductor, Inc.
    Inventor: Yoshitaka Sasaki
  • Patent number: 5624861
    Abstract: A manufacturing method of a semiconductor device includes the steps of depositing a metallic film (light-shielding film), an insulating film and a semiconductor film in this order on an insulating substrate, and after patterning the insulating film and the semiconductor film in a predetermined shape, oxidizing an exposed region of the metallic film using the insulating film and the semiconductor film as a mask. As a result, the light-shielding film composed of the metallic film is formed so as to cover the semiconductor film to block light from an external portion. The manufacturing method permits a process of forming a resist pattern for use in forming the light-shielding film and a process of etching the light-shielding film to be omitted, thereby reducing the required number of processes. Moreover, as a level difference is not generated around the light-shielding film, a generation of a level difference on the semiconductor film can be prevented.
    Type: Grant
    Filed: July 23, 1996
    Date of Patent: April 29, 1997
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Tsukasa Shibuya