Patents by Inventor Douglas J. Tweet

Douglas J. Tweet has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20040135138
    Abstract: A dual gate strained-Si MOSFET with thin SiGe dislocation regions and a method for fabricating the same are provided. The method comprises: forming a first layer of relaxed SiGe overlying a substrate, having a thickness of less than 5000 Å; forming a second layer of relaxed SiGe overlying the substrate and adjacent to the first layer of SiGe, having a thickness of less than 5000 Å; forming a layer of strained-Si overlying the first and second SiGe layers; forming a shallow trench isolation region interposed between the first SiGe layer and the second SiGe layer; forming an n-well in the substrate and the overlying first layer of SiGe; forming a p-well in the substrate and the overlying second layer of SiGe; forming channel regions, in the strained-Si, and forming PMOS and NMOS transistor source and drain regions.
    Type: Application
    Filed: January 15, 2003
    Publication date: July 15, 2004
    Applicant: Sharp Laboratories of America, Inc.
    Inventors: Sheng Teng Hsu, Jong-Jan Lee, Douglas J. Tweet, Jer-Shen Maa
  • Publication number: 20040087119
    Abstract: A method of forming a SiGe layer having a relatively high Ge content includes preparing a silicon substrate; depositing a layer of strained SiGe to a thickness of between about 100 nm to 500 nm, wherein the Ge content of the SiGe layer is equal to or greater than 20%, by molecular weight; implanting H2+ ions into the SiGe layer; irradiating the substrate and SiGe layer, to relax the SiGe layer; and depositing a layer of tensile-strained silicon on the relaxed SiGe layer to a thickness of between about 5 nm to 30 nm.
    Type: Application
    Filed: July 22, 2003
    Publication date: May 6, 2004
    Applicant: Sharp Laboratories of America, Inc.
    Inventors: Jer-Shen Maa, Jong-Jan Lee, Douglas J. Tweet, Sheng Teng Hsu
  • Patent number: 6720258
    Abstract: An integrated circuit device, and a method of manufacturing the same, comprises an epitaxial nickel silicide on (100) Si, or a stable nickel silicide on amorphous Si, fabricated with a cobalt interlayer. In one embodiment the method comprises depositing a cobalt (Co) interface layer between the Ni and Si layers prior to the silicidation reaction. The cobalt interlayer regulates the flux of the Ni atoms through the cobalt/nickel/silicon alloy layer formed from the reaction of the cobalt interlayer with the nickel and the silicon so that the Ni atoms reach the Si interface at a similar rate, i.e., without any orientation preference, so as to form a uniform layer of nickel silicide. The nickel silicide may be annealed to form a uniform crystalline nickel disilicide. Accordingly, a single crystal nickel silicide on (100) Si or on amorphous Si is achieved wherein the nickel silicide has improved stability and may be utilized in ultra-shallow junction devices.
    Type: Grant
    Filed: December 12, 2002
    Date of Patent: April 13, 2004
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: Jer-shen Maa, Douglas J. Tweet, Yoshi Ono, Fengyan Zhang, Sheng Teng Hsu
  • Patent number: 6716691
    Abstract: A method of fabricating a CMOS have self-aligned shallow trench isolation, includes preparing a silicon substrate; forming a gate stack; depositing a layer of first polysilicon; trenching the substrate by shallow trench isolation to form a trench; filling the trench with oxide; depositing a second layer of polysilicon wherein the top surface of the second polysilicon layer is above the top surface of the first polysilicon layer; depositing a sacrificial oxide layer having a thickness of at least 1.5× that of the first polysilicon layer; CMP the sacrificial oxide layer to the level of the upper surface of the second polysilicon layer; depositing a third layer of polysilicon; patterning and etching the gate stack; implanting ions to form a source region, a drain region and the polysilicon gate; and completing the CMOS structure.
    Type: Grant
    Filed: June 25, 2003
    Date of Patent: April 6, 2004
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: David R. Evans, Sheng Teng Hsu, Bruce D. Ulrich, Douglas J. Tweet, Lisa H. Stecker
  • Publication number: 20040048450
    Abstract: A method of fabricating a Si1−XGeX film on a silicon substrate includes preparing a silicon substrate; epitaxially depositing a Si1−XGeX layer on the silicon substrate forming a Si1−XGeX/Si interface there between; epitaxially growing a silicon cap on the Si1−XGeX layer; implanting hydrogen ions through the Si1−XGeX layer to a depth of between about 3 nm to 100 nm below the Si1−XGeX/Si interface; amorphizing the Si1−XGeX layer to form an amorphous, graded SiGe layer; and annealing the structure at a temperature of between about 650° C. to 1100° C. for between about ten seconds and sixty minutes to recrystallize the SiGe layer.
    Type: Application
    Filed: September 9, 2002
    Publication date: March 11, 2004
    Applicant: Sharp Laboratories of America, Inc.
    Inventors: Douglas J. Tweet, Jer-Shen Maa, Jong-Jan Lee, Sheng Teng Hsu
  • Patent number: 6703293
    Abstract: A method of fabricating a Si1−XGeX film on a silicon substrate includes preparing a silicon substrate; epitaxially depositing a Si1−XGeX layer on the silicon substrate forming a Si1−XGeX/Si interface there between; amorphizing the Si1−XGeX layer at a temperature greater than Tc to form an amorphous, graded SiGe layer; and annealing the structure at a temperature of between about 650° C. to 1100° C. for between about ten seconds and sixty minutes to recrystallize the SiGe layer.
    Type: Grant
    Filed: July 11, 2002
    Date of Patent: March 9, 2004
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: Douglas J. Tweet, Sheng Teng Hsu, Jer-shen Maa, Jong-Jan Lee
  • Patent number: 6699764
    Abstract: A method of fabricating a Si1−XGeX film on a silicon substrate includes preparing a silicon substrate; epitaxially depositing a Si1−XGeX layer on the silicon substrate forming a Si1−XGeX/Si interface there between; epitaxially growing a silicon cap on the Si1−XGeX layer; implanting hydrogen ions through the Si1−XGeX layer to a depth of between about 3 nm to 100 nm below the Si1−XGeX/Si interface; amorphizing the Si1−XGeX layer to form an amorphous, graded SiGe layer; and annealing the structure at a temperature of between about 650° C. to 1100° C. for between about ten seconds and sixty minutes to recrystallize the SiGe layer.
    Type: Grant
    Filed: September 9, 2002
    Date of Patent: March 2, 2004
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: Douglas J. Tweet, Jer-shen Maa, Jong-Jan Lee, Sheng Teng Hsu
  • Publication number: 20040009626
    Abstract: A method of fabricating a Si1-XGeX film on a silicon substrate includes preparing a silicon substrate; epitaxially depositing a Si1-XGeX layer on the silicon substrate forming a Si1-XGeX/Si interface there between; amorphizing the Si1-XGeX layer at a temperature greater than Tc to form an amorphous, graded SiGe layer; and annealing the structure at a temperature of between about 650° C. to 1100° C. for between about ten seconds and sixty minutes to recrystallize the SiGe layer.
    Type: Application
    Filed: July 11, 2002
    Publication date: January 15, 2004
    Inventors: Douglas J. Tweet, Sheng Teng Hsu, Jer-shen Maa, Jong-Jan Lee
  • Publication number: 20030186503
    Abstract: A modified STI process is provided comprising forming a first polysilicon layer over a substrate. Forming a trench through the first polysilicon layer and into the substrate, and filling the trench with an oxide layer. Depositing a second polysilicon layer over the oxide, such that the bottom of the second polysilicon layer within the trench is above the bottom of the first polysilicon layer, and the top of the second polysilicon layer within the trench is below the top of the first polysilicon layer. The resulting structure may then be planarized using a CMP process. An alignment key may be formed by selectively etching the oxide layer. A third polysilicon layer may then be deposited and patterned using photoresist to form a gate structure. During patterning, exposed second polysilicon layer is etched. An etch stop is detected at the completion of removal of the second polysilicon layer. A thin layer of the first polysilicon layer remains, to be carefully removed using a subsequent selective etch process.
    Type: Application
    Filed: March 29, 2002
    Publication date: October 2, 2003
    Inventors: David R. Evans, Sheng Teng Hsu, Bruce D. Ulrich, Douglas J. Tweet, Lisa H. Stecker
  • Patent number: 6627510
    Abstract: A modified STI process is provided comprising forming a first polysilicon layer over a substrate. Forming a trench through the first polysilicon layer and into the substrate, and filling the trench with an oxide layer. Depositing a second polysilicon layer over the oxide, such that the bottom of the second polysilicon layer within the trench is above the bottom of the first polysilicon layer, and the top of the second polysilicon layer within the trench is below the top of the first polysilicon layer. The resulting structure may then be planarized using a CMP process. An alignment key may be formed by selectively etching the oxide layer. A third polysilicon layer may then be deposited and patterned using photoresist to form a gate structure. During patterning, exposed second polysilicon layer is etched. An etch stop is detected at the completion of removal of the second polysilicon layer. A thin layer of the first polysilicon layer remains, to be carefully removed using a subsequent selective etch process.
    Type: Grant
    Filed: March 29, 2002
    Date of Patent: September 30, 2003
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: David R. Evans, Sheng Teng Hsu, Bruce D. Ulrich, Douglas J. Tweet, Lisa H. Stecker
  • Publication number: 20030172866
    Abstract: A method is provided for forming a relaxed single-crystal silicon germanium film on a silicon substrate. Also provided is a film structure with a relaxed layer of graded silicon germanium on a silicon substrate. The method comprises: providing a silicon (Si) substrate with a top surface; growing a graded layer of strained single-crystal Si1-xGex having a bottom surface overlying the Si substrate top surface and a top surface, where x increases with the Si1-xGex layer thickness in the range between 0.03 and 0.
    Type: Application
    Filed: March 13, 2002
    Publication date: September 18, 2003
    Inventors: Sheng Teng Hsu, Jong-Jan Lee, Jer-shen Maa, Douglas J. Tweet
  • Publication number: 20030104694
    Abstract: An integrated circuit device, and a method of manufacturing the same, comprises an epitaxial nickel silicide on (100) Si, or a stable nickel silicide on amorphous Si, fabricated with a cobalt interlayer. In one embodiment the method comprises depositing a cobalt (Co) interface layer between the Ni and Si layers prior to the silicidation reaction. The cobalt interlayer regulates the flux of the Ni atoms through the cobalt/nickel/silicon alloy layer formed from the reaction of the cobalt interlayer with the nickel and the silicon so that the Ni atoms reach the Si interface at a similar rate, i.e., without any orientation preference, so as to form a uniform layer of nickel silicide. The nickel silicide may be annealed to form a uniform crystalline nickel disilicide. Accordingly, a single crystal nickel silicide on (100) Si or on amorphous Si is achieved wherein the nickel silicide has improved stability and may be utilized in ultra-shallow junction devices.
    Type: Application
    Filed: December 12, 2002
    Publication date: June 5, 2003
    Applicant: Sharp Laboratories of America, Inc.
    Inventors: Jer-Shen Maa, Douglas J. Tweet, Yoshi Ono, Fengyan Zhang, Sheng Teng Hsu
  • Patent number: 6562703
    Abstract: A method is provided for forming a relaxed silicon germanium layer with a high germanium content on a silicon substrate. The method comprises: depositing a single-crystal silicon (Si) buffer layer overlying the silicon substrate; depositing a layer of single-crystal silicon germanium (Si1−xGex) overlying the Si buffer layer having a thickness of 1000 to 5000 Å; implanting the Si1−xGex layer with ionized molecular hydrogen (H2+) a projected range of approximately 100 to 300 Å into the underlying Si buffer layer; optionally, implanting the Si1−xGex layer with a species selected such as boron, He, or Si; annealing; and, in response to the annealing, converting the Si1−xGex layer to a relaxed Si1−xGex layer. Optionally, after annealing, an additional layer of single-crystal Si1−xGex having a thickness of greater than 1000 Å can be deposited overlying the relaxed layer of Si1−xGex.
    Type: Grant
    Filed: March 13, 2002
    Date of Patent: May 13, 2003
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: Jer-Shen Maa, Douglas J. Tweet, Sheng Teng Hsu, Jong-Jan Lee
  • Patent number: 6534871
    Abstract: An integrated circuit device, and a method of manufacturing the same, comprises an epitaxial nickel silicide on (100) Si, or a stable nickel silicide on amorphous Si, fabricated with a cobalt interlayer. In one embodiment the method comprises depositing a cobalt (Co) interface layer between the Ni and Si layers prior to the silicidation reaction. The cobalt interlayer regulates the flux of the Ni atoms through the cobalt/nickel/silicon alloy layer formed from the reaction of the cobalt interlayer with the nickel and the silicon so that the Ni atoms reach the Si interface at a similar rate, i.e., without any orientation preference, so as to form a uniform layer of nickel silicide. The nickel silicide may be annealed to form a uniform crystalline nickel disilicide. Accordingly, a single crystal nickel silicide on (100) Si or on amorphous Si is achieved wherein the nickel silicide has improved stability and may be utilized in ultra-shallow junction devices.
    Type: Grant
    Filed: May 14, 2001
    Date of Patent: March 18, 2003
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: Jer-shen Maa, Douglas J. Tweet, Yoshi Ono, Fengyan Zhang, Sheng Teng Hsu
  • Publication number: 20020167048
    Abstract: The present invention comprises a thin Si/SiGe stack on top of an equally thin top Si layer of a SOI substrate. The SiGe layer is compressively strained but partially relaxed and the Si layers are each tensily strained, without high dislocation densities. The silicon layer of the SOI substrate has a thickness of approximately 10 to 40 nm. The SiGe layer has a thickness of approximately 5 to 50 nm. The top, second Si layer has a thickness of approximately 2 to 50 nm. Part of the top Si layer may be thermally oxidized to form a gate dielectric for MOS applications.
    Type: Application
    Filed: May 14, 2001
    Publication date: November 14, 2002
    Inventors: Douglas J. Tweet, Sheng Teng Hsu
  • Publication number: 20020168802
    Abstract: The present invention provides a method of fabricating a simple SiGe/SOI structure. In particular, the top silicon layer of a SOI is converted to Si1−xGex, by growing a SiGe epitaxial layer followed by relaxation annealing at a temperature between 550° C. to 1050° C. This temperature treatment relaxes the SiGe to convert the top silicon layer into a relaxed SiGe layer and eliminates defects in the SOI film. Accordingly, a very low defect density SiGe crystal is obtainable. The SiGe layer is capped with an epitaxial silicon layer. Because the silicon layer is grown onto the relaxed SiGe, the top silicon layer is a strained silicon layer. Therefore, higher electron and hole mobility are obtained. The buried oxide interface acts as a buffer for the SiGe relaxation. There is no requirement for a graded SiGe layer. As a result the defect density in this structure can be substantially lower than that of prior art structures.
    Type: Application
    Filed: October 30, 2001
    Publication date: November 14, 2002
    Inventors: Sheng Teng Hsu, Douglas J. Tweet, David R. Evans
  • Publication number: 20020168853
    Abstract: An integrated circuit device, and a method of manufacturing the same, comprises an epitaxial nickel silicide on (100) Si, or a stable nickel silicide on amorphous Si, fabricated with a cobalt interlayer. In one embodiment the method comprises depositing a cobalt (Co) interface layer between the Ni and Si layers prior to the silicidation reaction. The cobalt interlayer regulates the flux of the Ni atoms through the cobalt/nickel/silicon alloy layer formed from the reaction of the cobalt interlayer with the nickel and the silicon so that the Ni atoms reach the Si interface at a similar rate, i.e., without any orientation preference, so as to form a uniform layer of nickel silicide. The nickel silicide may be annealed to form a uniform crystalline nickel disilicide. Accordingly, a single crystal nickel silicide on (100) Si or on amorphous Si is achieved wherein the nickel silicide has improved stability and may be utilized in ultra-shallow junction devices.
    Type: Application
    Filed: May 14, 2001
    Publication date: November 14, 2002
    Inventors: Jer-shen Maa, Douglas J. Tweet, Yoshi Ono, Fengyan Zhang, Sheng Teng Hsu
  • Patent number: 6200866
    Abstract: A method of fabricating a MOSFET is provided, including: depositing an oxide layer on a silicon substrate for device isolation; forming a silicon based alloy island above a gate region in the substrate, wherein the silicon based alloy comprises a silicon germanium alloy or a silicon tin alloy or another alloy of Group IV-B elements; building a sidewall about the silicon based alloy island; forming a source region and a drain region in the substrate; removing the silicon based alloy island, thereby leaving a void over the gate region; filing the void and the areas over the source region and the drain region; and planarizing the upper surface of the structure by chemical mechanical polishing. Alternative embodiments providing conventional and raised source/drain structures are disclosed.
    Type: Grant
    Filed: September 30, 1999
    Date of Patent: March 13, 2001
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: Yanjun Ma, Douglas J. Tweet, David R. Evans, Yoshi Ono