Patents by Inventor Marwan H. Khater

Marwan H. Khater 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).

  • Patent number: 7170083
    Abstract: A structure and method where C is incorporated into the collector region of a heterojunction bipolar device by a method which does not include C ion implantation are provided. In the present invention, C is incorporated into the collector by epitaxy in a perimeter trench etched into the collector region to better control the carbon profile and location. The trench is formed by etching the collector region using the trench isolation regions and a patterned layer over the center part of the collector as masks. Then, Si:C is grown using selective epitaxy inside the trench to form a Si:C region with sharp and well-defined edges. The depth, width and C content can be optimized to control and tailor the collector implant diffusion and to reduce the perimeter component of parasitic CCB.
    Type: Grant
    Filed: January 7, 2005
    Date of Patent: January 30, 2007
    Assignee: International Business Machines Corporation
    Inventors: Gregory G. Freeman, Marwan H. Khater, Rajendran Krishnasamy, Kathryn T. Schonenberg, Andreas D Stricker
  • Patent number: 7144787
    Abstract: Methods of boosting the performance of bipolar transistor, especially SiGe heterojunction bipolar transistors, is provided together with the structure that is formed by the inventive methods. The methods include providing a species-rich dopant region comprising C, a noble gas, or mixtures thereof into at least a collector. The species-rich dopant region forms a perimeter or donut-shaped dopant region around a center portion of the collector. A first conductivity type dopant is then implanted into the center portion of the collector to form a first conductivity type dopant region that is laterally constrained, i.e., confined, by the outer species-rich dopant region.
    Type: Grant
    Filed: May 9, 2005
    Date of Patent: December 5, 2006
    Assignee: International Business Machines Corporation
    Inventors: Omer H. Dokumaci, Gregory G. Freeman, Marwan H. Khater, Rajendran Krishnasamy, Kathryn T. Schonenberg
  • Patent number: 7119416
    Abstract: The invention includes methods of fabricating a bipolar transistor that adds a silicon germanium (SiGe) layer or a third insulator layer of, e.g., high pressure oxide (HIPOX), atop an emitter cap adjacent the intrinsic base prior to forming a link-up layer. This addition allows for removal of the link-up layer using wet etch chemistries to remove the excess SiGe or third insulator layer formed atop the emitter cap without using oxidation. In this case, an oxide section (formed by deposition of an oxide or segregation of the above-mentioned HIPOX layer) and nitride spacer can be used to form the emitter-base isolation. The invention results in lower thermal cycle, lower stress levels, and more control over the emitter cap layer thickness, which are drawbacks of the first embodiment. The invention also includes the resulting bipolar transistor structure.
    Type: Grant
    Filed: June 29, 2005
    Date of Patent: October 10, 2006
    Assignee: International Business Machines Corporation
    Inventors: Thomas N. Adam, Kevin K. Chan, Alvin J. Joseph, Marwan H. Khater, Qizhi Liu, Beth Ann Rainey, Kathryn T. Schonenberg
  • Patent number: 7102205
    Abstract: A method of increasing mobility of charge carriers in a bipolar device comprises the steps of: creating compressive strain in the device to increase mobility of holes in an intrinsic base of the device; and creating tensile strain in the device to increase mobility of electrons in the intrinsic base of the device. The compressive and tensile strains are created by forming a stress layer in close proximity to the intrinsic base of the device. The stress layer is at least partially embedded in a base layer of the device, adjacent an emitter structure of the device. The stress layer has different lattice constant than the intrinsic base. Method and apparatus are described.
    Type: Grant
    Filed: September 1, 2004
    Date of Patent: September 5, 2006
    Assignee: International Business Machines Corporation
    Inventors: Dureseti Chidambarrao, Gregory G. Freeman, Marwan H. Khater
  • Patent number: 7087940
    Abstract: A bipolar transistor structure and method of making the bipolar transistor are provided. The bipolar transistor includes a collector region, an intrinsic base layer overlying the collector region, and an emitter overlying the intrinsic base layer. An opened etch stop layer includes a layer of dielectric material overlying the intrinsic base, the opened etch stop layer self-aligned to the emitter. The bipolar transistor further includes a raised extrinsic base self-aligned to the emitter, the raised extrinsic base overlying the intrinsic base layer.
    Type: Grant
    Filed: April 22, 2004
    Date of Patent: August 8, 2006
    Assignee: International Business Machines Corporation
    Inventors: Marwan H. Khater, Francois Pagette
  • Patent number: 7037798
    Abstract: The invention includes methods of fabricating a bipolar transistor that adds a silicon germanium (SiGe) layer or a third insulator layer of, e.g., high pressure oxide (HIPOX), atop an emitter cap adjacent the intrinsic base prior to forming a link-up layer. This addition allows for removal of the link-up layer using wet etch chemistries to remove the excess SiGe or third insulator layer formed atop the emitter cap without using oxidation. In this case, an oxide section (formed by deposition of an oxide or segregation of the above-mentioned HIPOX layer) and nitride spacer can be used to form the emitter-base isolation. The invention results in lower thermal cycle, lower stress levels, and more control over the emitter cap layer thickness, which are drawbacks of the first embodiment. The invention also includes the resulting bipolar transistor structure.
    Type: Grant
    Filed: November 12, 2004
    Date of Patent: May 2, 2006
    Assignee: International Business Machines Corporation
    Inventors: Thomas N. Adam, Kevin K. Chan, Alvin J. Joseph, Marwan H. Khater, Qizhi Liu, Beth Ann Rainey, Kathryn T. Schonenberg
  • Patent number: 7002221
    Abstract: A bipolar transistor with raised extrinsic base and selectable self-alignment between the extrinsic base and the emitter is disclosed. The fabrication method may include the formation of a predefined thickness of a first extrinsic base layer of polysilicon or silicon on an intrinsic base. A dielectric landing pad is then formed by lithography on the first extrinsic base layer. Next, a second extrinsic base layer of polysilicon or silicon is formed on top of the dielectric landing pad to finalize the raised extrinsic base total thickness. An emitter opening is formed using lithography and RIE, where the second extrinsic base layer is etched stopping on the dielectric landing pad. The degree of self-alignment between the emitter and the raised extrinsic base is achieved by selecting the first extrinsic base layer thickness, the dielectric landing pad width, and the spacer width.
    Type: Grant
    Filed: August 29, 2003
    Date of Patent: February 21, 2006
    Assignee: International Business Machines Corporation
    Inventors: Marwan H. Khater, James S. Dunn, David L. Harame, Alvin J. Joseph, Qizhi Liu, Francois Pagette, Stephen A. St. Onge, Andreas D. Stricker
  • Patent number: 6982442
    Abstract: A heterojunction bipolar transistor (HBT) and method of making an HBT are provided. The HBT includes a collector, and an intrinsic base overlying the collector. The intrinsic base includes a layer of a single-crystal semiconductor alloy. The HBT further includes a raised extrinsic base having a first semiconductive layer overlying the intrinsic base and a second semiconductive layer formed on the first semiconductive layer. An emitter overlies the intrinsic base, and is disposed in an opening of the first and second semiconductive layers, such that the raised extrinsic base is self-aligned to the emitter.
    Type: Grant
    Filed: January 6, 2004
    Date of Patent: January 3, 2006
    Assignee: International Business Machines Corporation
    Inventors: Kevin K. Chan, Marwan H. Khater, Kathryn T. Schonenberg, Panda Siddhartha
  • Patent number: 6979884
    Abstract: The present invention provides a bipolar transistor having a raised extrinsic base silicide and an emitter contact border that are self-aligned. The bipolar transistor of the present invention exhibit reduced parasitics as compared with bipolar transistors that do not include a self-aligned silicide and a self-aligned emitter contact border. The present invention also is related to methods of fabricating the inventive bipolar transistor structure. In the methods of the present invention, a block emitter polysilicon region replaces a conventional T-shaped emitter polysilicon.
    Type: Grant
    Filed: December 4, 2003
    Date of Patent: December 27, 2005
    Assignee: International Business Machines Corporation
    Inventors: David C. Ahlgren, Gregory G. Freeman, Marwan H. Khater, Richard P. Volant
  • Patent number: 6972443
    Abstract: A bipolar transistor is provided which includes a collector region, an intrinsic base layer including a single-crystal semiconductor overlying the collector region, and an emitter disposed within a first opening overlying the intrinsic base layer. The bipolar transistor includes a raised extrinsic base, which in turn includes a raised extrinsic base layer and a link-up region which electrically connects the raised extrinsic base layer to the intrinsic base layer. The link-up region also self-aligns the raised extrinsic base to the emitter. The link-up region is disposed in a second opening separate from the first opening and in an undercut region extending from the second opening below the raised extrinsic base layer.
    Type: Grant
    Filed: April 22, 2004
    Date of Patent: December 6, 2005
    Assignee: International Business Machines Corporation
    Inventor: Marwan H. Khater
  • Patent number: 6965133
    Abstract: Methods for fabricating a heterojunction bipolar transistor having a raised extrinsic base is provided in which the base resistance is reduced by forming a silicide atop the raised extrinsic base that extends to the emitter region in a self-aligned manner. The silicide formation is incorporated into a BiCMOS process flow after the raised extrinsic base has been formed. The present invention also provides a heterojunction bipolar transistor having a raised extrinsic base and a silicide located atop the raised extrinsic base. The silicide atop the raised extrinsic base extends to the emitter in a self-aligned manner. The emitter is separated from the silicide by a spacer.
    Type: Grant
    Filed: March 13, 2004
    Date of Patent: November 15, 2005
    Assignee: International Business Machines Corporation
    Inventors: Peter J. Geiss, Marwan H. Khater, Qizhi Liu, Randy W. Mann, Robert J. Purtell, BethAnn Rainey, Jae-Sung Rieh, Andreas D. Stricker
  • Patent number: 6960820
    Abstract: A self-aligned bipolar transistor structure having a raised extrinsic base comprising an outer region and an inner region of different doping concentrations and methods of fabricating the transistor are disclosed. More specifically, the self-alignment of the extrinsic base to the emitter is accomplished by forming the extrinsic base in two regions. First, a first material of silicon or polysilicon having a first doping concentration is provided to form an outer extrinsic base region. Then a first opening is formed in the first material layer by lithography within which a dummy emitter pedestal is formed, which results in forming a trench between the sidewall of the first opening and the dummy pedestal. A second material of a second doping concentration is then provided inside the trench forming a distinct inner extrinsic base extension region to self-align the raised extrinsic base edge to the dummy pedestal edge.
    Type: Grant
    Filed: July 1, 2003
    Date of Patent: November 1, 2005
    Assignee: International Business Machines Corporation
    Inventors: Gregory G. Freeman, Marwan H. Khater, Francois Pagette
  • Publication number: 20050233535
    Abstract: A self-aligned bipolar transistor structure having a raised extrinsic base comprising an outer region and an inner region of different doping concentrations and methods of fabricating the transistor are disclosed. More specifically, the self-alignment of the extrinsic base to the emitter is accomplished by forming the extrinsic base in two regions. First, a first material of silicon or polysilicon having a first doping concentration is provided to form an outer extrinsic base region. Then a first opening is formed in the first material layer by lithography within which a dummy emitter pedestal is formed, which results in forming a trench between the sidewall of the first opening and the dummy pedestal. A second material of a second doping concentration is then provided inside the trench forming a distinct inner extrinsic base extension region to self-align the raised extrinsic base edge to the dummy pedestal edge.
    Type: Application
    Filed: June 13, 2005
    Publication date: October 20, 2005
    Inventors: Gregory G. Freeman, Marwan H. Khater, Francois Pagette
  • Patent number: 6864560
    Abstract: A bipolar vertical transistor is formed in a silicon semiconductor substrate which has an upper surface with STI regions formed therein composed of a dielectric material formed in the substrate having inner ends and top surfaces. A doped collector region is formed in the substrate between a pair of the STI regions. A counterdoped intrinsic base region is formed on the upper surface of the substrate between the pair of the STI regions with a margin between the intrinsic base region and the pair of STI regions, the intrinsic base region having edges. A doped emitter region is formed above the intrinsic base region spaced away from the edges. A shallow isolation extension region composed of a dielectric material is next to the edges of the intrinsic base region formed in the margin between the STI regions and the intrinsic base region.
    Type: Grant
    Filed: March 28, 2003
    Date of Patent: March 8, 2005
    Assignee: International Business Machines Corporation
    Inventors: Marwan H. Khater, Jae-Sung Rieh, Andreas Daniel Stricker, Gregory Gower Freeman, Kathryn Turner Schonenberg
  • Patent number: 6858485
    Abstract: A double-polysilicon, self-aligned bipolar transistor has a collector region formed in a doped semiconductor substrate, an intrinsic counterdoped base formed on the surface of the substrate and a doped emitter formed in the surface of the intrinsic base. Form an etch stop dielectric layer over the intrinsic base layer above the collector. Form a base contact layer of a conductive material over the etch stop dielectric layer and the intrinsic base layer. Form a second dielectric layer over the base contact layer. Etch a wide window through the dielectric layer and the base contact layer stopping the etching of the window at the etch stop dielectric layer. Form an island or a peninsula narrowing the wide window leaving at least one narrowed window within the wide window. Form sidewall spacers in the either the wide window or the narrowed window. Fill the windows with doped polysilicon to form an extrinsic emitter. Form an emitter below the extrinsic emitter in the surface of the intrinsic base.
    Type: Grant
    Filed: May 7, 2003
    Date of Patent: February 22, 2005
    Assignee: International Business Machines Corporation
    Inventors: Gregory G. Freeman, Marwan H. Khater, Francois Pagette, Andreas D. Stricker
  • Publication number: 20040222496
    Abstract: A double-polysilicon, self-aligned bipolar transistor has a collector region formed in a doped semiconductor substrate, an intrinsic counterdoped base formed on the surface of the substrate and a doped emitter formed in the surface of the intrinsic base. Form an etch stop dielectric layer over the intrinsic base layer above the collector. Form a base contact layer of a conductive material over the etch stop dielectric layer and the intrinsic base layer. Form a second dielectric layer over the base contact layer. Etch a wide window through the dielectric layer and the base contact layer stopping the etching of the window at the etch stop dielectric layer. Form an island or a peninsula narrowing the wide window leaving at least one narrowed window within the wide window. Form sidewall spacers in the either the wide window or the narrowed window. Fill the windows with doped polysilicon to form an extrinsic emitter. Form an emitter below the extrinsic emitter in the surface of the intrinsic base.
    Type: Application
    Filed: May 7, 2003
    Publication date: November 11, 2004
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Gregory G. Freeman, Marwan H. Khater, Francois Pagette, Andreas D. Stricker
  • Publication number: 20040188797
    Abstract: A bipolar vertical transistor is formed in a silicon semiconductor substrate which has an upper surface with STI regions formed therein composed of a dielectric material formed in the substrate having inner ends and top surfaces. A doped collector region is formed in the substrate between a pair of the STI regions. A counterdoped intrinsic base region is formed on the upper surface of the substrate between the pair of the STI regions with a margin between the intrinsic base region and the pair of STI regions, the intrinsic base region having edges. A doped emitter region is formed above the intrinsic base region spaced away from the edges. A shallow isolation extension region composed of a dielectric material is next to the edges of the intrinsic base region formed in the margin between the STI regions and the intrinsic base region.
    Type: Application
    Filed: March 28, 2003
    Publication date: September 30, 2004
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Marwan H. Khater, Jae-Sung Rieh, Andreas Daniel Stricker, Gregory Gower Freeman, Kathryn Turner Schonenberg
  • Patent number: 6676800
    Abstract: A method and apparatus for cleaning semiconductor wafers, next generation lithography (NGL) masks, and optical photomasks as well as test wafers and in service NGL and optical masks is disclosed. The method and apparatus utilize reactive gases and gas mixtures and mechanical agitation to enhance particle removal. The addition of a reactive gas process to an inert gas feed enhances the plasma cleaning process by breaking chemical bonds which form between surface particles and a substrate, consequently improving cleaning efficiency.
    Type: Grant
    Filed: March 15, 2000
    Date of Patent: January 13, 2004
    Assignee: Applied Materials, Inc.
    Inventors: John J. Festa, Darryl Bennett, Joel Brad Bailey, Lawrence J. Overzet, Marwan H. Khater, Siva K. Kanakasabapathy
  • Patent number: 6459066
    Abstract: A properly designed and positioned Faraday shield/dielectric spacer/source-coil assembly is used to nearly fix the input impedance of an Inductively Coupled Plasma (ICP) source-coil, making a variable matching network almost unnecessary, and allowing for pulsed plasma processing with very little reflected power. Further, the nearly constant input-impedance also means a nearly constant standing wave pattern on the ICP source-coil and constant power deposition symmetry as well as plasma uniformity independent of RF power, gas pressure and gas composition. This is not possible without a properly designed and positioned Faraday shield because the source-coil impedance is coupled to that of the plasma and changes significantly with the plasma conditions.
    Type: Grant
    Filed: June 8, 2001
    Date of Patent: October 1, 2002
    Assignee: Board of Regents, The University of Texas System
    Inventors: Marwan H. Khater, Lawrence J. Overzet
  • Publication number: 20020023899
    Abstract: A properly designed and positioned Faraday shield/dielectric spacer/source-coil assembly is used to nearly fix the input impedance of an Inductively Coupled Plasma (ICP) source-coil, making a variable matching network almost unnecessary, and allowing for pulsed plasma processing with very little reflected power. Further, the nearly constant input-impedance also means a nearly constant standing wave pattern on the ICP source-coil and constant power deposition symmetry as well as plasma uniformity independent of RF power, gas pressure and gas composition. This is not possible without a properly designed and positioned Faraday shield because the source-coil impedance is coupled to that of the plasma and changes significantly with the plasma conditions.
    Type: Application
    Filed: June 8, 2001
    Publication date: February 28, 2002
    Inventors: Marwan H. Khater, Lawrence J. Overzet