Heterojunction Transistor (epo) Patents (Class 257/E21.371)
  • Publication number: 20080237643
    Abstract: A heterojunction bipolar transistor comprising a substrate; a collector on the substrate; a base layer on the collector; an emitter layer on the base layer; the emitter layer comprising an upper emitter layer and a lower emitter layer between the upper emitter layer and base; the collector, base and emitter layers being npn or pnp doped respectively; characterised in that the lower emitter layer has a larger bandgap than the base layer and is AlxIn1-xP or GaxAl1-xP, x being in the range 0+ to 1.
    Type: Application
    Filed: March 27, 2008
    Publication date: October 2, 2008
    Applicant: FITRONIC COMPOUND SEMICONDUCTORS LIMITED
    Inventors: Matthew Francis O'Keefe, Robert Grey, Michael Charles Clausen, Richard Alun Davies
  • Publication number: 20080230809
    Abstract: A sophisticated semiconductor device capable of being fabricated without introducing a high-precision exposure apparatus is obtained. This semiconductor device includes a conductive layer formed on a first conductivity type collector layer, a first conductivity type emitter electrode formed on the conductive layer and a protruding portion protruding from an outer side toward an inner side of the emitter electrode along an interface between the emitter electrode and the conductive layer. The conductive layer has a first conductivity type emitter diffusion layer in contact with the emitter electrode through the protruding portion and a second conductivity type base layer.
    Type: Application
    Filed: February 28, 2008
    Publication date: September 25, 2008
    Inventor: Yoshikazu Ibara
  • Publication number: 20080230803
    Abstract: A semiconductor device that is fabricated by metamorphic epitaxial growth processes, and includes a combined graded base and active layer having a thickness less than 5000 ?. In one non-limiting embodiment, the semiconductor device is an HBT device that includes a combined doped graded buffer and sub-collector layer having a thickness less than 5000 ?, and a concentration of indium of about 86% at a top of the combined layer.
    Type: Application
    Filed: March 22, 2007
    Publication date: September 25, 2008
    Applicant: Northrop Grumman Space & Mission Systems Corp.
    Inventors: Cedric Monier, Randy Sandhu, Abdullah Cavus, Augusto Gutierrez-Aitken
  • Publication number: 20080224174
    Abstract: A technology which allows an improvement in the moisture resistance of a semiconductor device is provided. In a GaAs substrate as a semi-insulating substrate, a HBT is formed in an element formation region, while an isolation region is formed in an insulating region. The isolation region formed in the insulating region is formed by introducing helium into the same semiconductor layers as the sub-collector semiconductor layer and collector semiconductor layer of the HBT. In an outer peripheral region, a conductive layer is formed to be exposed from protective films and coupled to a back surface electrode. Because a GND potential is supplied to the back surface electrode, the conductive layer is fixed to the GND potential. The conductive layer is formed of the same semiconductor layers as the sub-collector semiconductor layer and collector semiconductor layer of the HBT.
    Type: Application
    Filed: December 21, 2007
    Publication date: September 18, 2008
    Inventors: Kenji SASAKI, Ikuro Akazawa, Yoshinori Imamura, Atsushi Kurokawa, Tatsuhiko Ikeda, Hiroshi Inagawa, Yasunari Umemoto, Isao Obu
  • Publication number: 20080217654
    Abstract: A semiconductor device includes an element isolation film having an inclined portion and a flat portion, a protective film formed not on the inclined portion but on the flat portion of the element isolation film, and an outer base layer formed to extend from on a surface of an active region surrounded by the element isolation film to on the protective film.
    Type: Application
    Filed: February 28, 2008
    Publication date: September 11, 2008
    Inventors: Yuuji Kitamura, Yoshikazu Ibara
  • Publication number: 20080203434
    Abstract: The invention relates to a semiconductor device (10) with a substrate and a semiconductor body of silicon comprising a bipolar transistor with an emitter region (1), a base region (2) and a collector region (3) which are respectively of the N-type conductivity, the P-type conductivity and the N-type conductivity by the provision of suitable doping atoms, wherein the base region (2) comprises a mixed crystal of silicon and germanium, the base region (2) is separated from the emitter region by an intermediate region (22) of silicon having a doping concentration which is lower than the doping concentration of the emitter region (1) and with a thickness smaller than the thickness of the emitter region (1) and the emitter region (1) comprises a sub-region comprising a mixed crystal of silicon and germanium which is positioned at the side of emitter region (1) remote from the intermediate region (22).
    Type: Application
    Filed: September 22, 2006
    Publication date: August 28, 2008
    Applicant: NXP B.V.
    Inventors: Philippe Meunier-Beillard, Raymond James Duffy, Prabhat Agarwal, Godfridus Adrianus Maria Hurkx
  • Publication number: 20080203426
    Abstract: A metamorphic buffer layer is formed on a semi-insulating substrate by an epitaxial growth method, a collector layer, a base layer, an emitter layer and an emitter cap layer are sequentially laminated on the metamorphic buffer layer, and a collector electrode is provided in contact with an upper layer of the metamorphic buffer layer. The metamorphic buffer layer is doped with an impurity, in a concentration equivalent to or higher than that in a conventional sub-collector layer, by an impurity doping process during crystal growth so that the metamorphic buffer layer will be able to play the role of guiding the collector current to the collector electrode. Since the sub-collector layer, which is often formed of a ternary mixed crystal or the like having a high thermal resistance, can be omitted, the heat generated in the semiconductor device can be rapidly released into the substrate.
    Type: Application
    Filed: May 19, 2006
    Publication date: August 28, 2008
    Inventor: Masaya Uemura
  • Publication number: 20080191245
    Abstract: A method for forming a germanium-enriched region in a heterojunction bipolar transistor and a heterojunction bipolar transistor comprising a germanium-enriched region. A base having a silicon-germanium portion is formed over a collector. Thermal oxidation of the base causes a germanium-enriched region to form on a surface of the silicon-germanium portion subjected to the thermal oxidation. An emitter is formed overlying the germanium-enriched portion region. The germanium-enriched region imparts advantageous operating properties to the heterojunction bipolar transistor, including improved high-frequency/high-speed operation.
    Type: Application
    Filed: March 10, 2005
    Publication date: August 14, 2008
    Inventor: Michelle D. Griglione
  • Publication number: 20080191246
    Abstract: The invention, in one aspect, provides a method for fabricating a semiconductor device, which includes conducting an etch through an opening in an emitter layer to form a cavity from an underlying oxide layer that exposes a doped tub. A first silicon/germanium (SiGe) layer, which has a Ge concentration therein, is formed within the cavity and over the doped tub by adjusting a process parameter to induce a strain in the first SiGe layer. A second SiGe layer is formed over the first SiGe layer, and a capping layer is formed over the second SiGe layer.
    Type: Application
    Filed: February 12, 2007
    Publication date: August 14, 2008
    Applicant: Agere Systems Inc.
    Inventors: Alan S. Chen, Mark Dyson, Nace M. Rossi, Ranbir Singh
  • Publication number: 20080166850
    Abstract: A bipolar transistor structure includes an intrinsic base layer formed over a collector layer, an emitter formed over the intrinsic base layer, and an extrinsic base layer formed over the intrinsic layer and adjacent the emitter. A ring shaped collector implant structure is formed within an upper portion of the collector layer, wherein the ring shaped collector implant structure is disposed so as to be aligned beneath a perimeter portion of the emitter.
    Type: Application
    Filed: March 13, 2008
    Publication date: July 10, 2008
    Applicant: International Business Machines Corporation
    Inventor: Francois Pagette
  • Publication number: 20080128749
    Abstract: A method and system for providing a semiconductor device is described. The method and system include providing a compound region and providing a doped region. The compound region includes an alloy having an impurity. The impurity has a graded profile in the compound region. The doped region includes a dopant having a profile. The profile includes a retrograde region. In one aspect, the semiconductor device is a bipolar transistor. In this aspect, the method and system include providing an emitter region, a collector region, and a compound base region. The compound base region resides between the emitter region and the collector region. The compound base region has a collector side and includes an alloy and a dopant having a profile. The profile includes a retrograde region residing on the collector side of the compound base region.
    Type: Application
    Filed: December 1, 2006
    Publication date: June 5, 2008
    Inventor: Darwin Gene Enicks
  • Publication number: 20080128754
    Abstract: Provided are a SiGe semiconductor device and a method of manufacturing the same.
    Type: Application
    Filed: November 29, 2007
    Publication date: June 5, 2008
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Sang Hun KIM, Hyun Cheol BAE, Sang Heung LEE
  • Publication number: 20080124882
    Abstract: A heterojunction bipolar transistor is formed in a semiconductor substrate of a first conductivity type including a collector region. A base region is formed on the substrate and an emitter region is formed over the base region. At least one of the collector, base and emitter regions includes a first region doped with an impurity having a first concentration and a second region doped with the impurity having a second concentration. Noise performance and reliability of the heterojunction bipolar transistor is improved without degrading ac performance.
    Type: Application
    Filed: November 9, 2007
    Publication date: May 29, 2008
    Inventors: Peter J. Geiss, Alvin J. Joseph, Rajendran Krishnasamy, Xuefeng Liu
  • Publication number: 20080124881
    Abstract: A SiGe bipolar transistor containing substantially no dislocation defects present between the emitter and collector region and a method of forming the same are provided. The SiGe bipolar transistor includes a collector region of a first conductivity type; a SiGe base region formed on a portion of said collector region; and an emitter region of said first conductivity type formed over a portion of said base region, wherein said collector region and said base region include carbon continuously therein. The SiGe base region is further doped with boron.
    Type: Application
    Filed: November 22, 2006
    Publication date: May 29, 2008
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Jack Ooh Chu, Douglas Duane Coolbaugh, James Stuart Dunn, David R. Greenberg, David L. Harame, Basanth Jagannathan, Robb Allen Johnson, Louis D. Lanzerotti, Kathryn Turner Schonenberg, Ryan Wayne Wuthrich
  • Publication number: 20080121937
    Abstract: A heterostructure bipolar transistor (HBT) and related methods are disclosed. In one embodiment, the HBT includes a substrate; a polysilicon emitter atop the substrate; a collector in the substrate; at least one isolation region adjacent to the collector; an intrinsic base including monocrystalline silicon germanium extending over each isolation region; and a monocrystalline extrinsic base. One method includes replacing isolation region formation with formation of porous implanted silicon, which is later converted to a dielectric. As a result, a monocrystalline silicon germanium profile base layer may be formed with extended lateral dimensions over the isolation region(s).
    Type: Application
    Filed: November 8, 2006
    Publication date: May 29, 2008
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Thomas N Adam, Thomas A. Wallner
  • Publication number: 20080121930
    Abstract: A heterostructure bipolar transistor (HBT) and related methods are disclosed. In one embodiment, the HBT includes a heterostructure bipolar transistor (HBT) including: a substrate; a monocrystalline emitter atop the substrate; a collector in the substrate; at least one isolation region adjacent to the collector; a monocrystalline silicon germanium (SiGe) intrinsic base extending over each isolation region; and a monocrystalline silicon extrinsic base. A method may include forming the intrinsic and extrinsic base and the emitter as monocrystalline, with the extrinsic base (and emitter) formed in a self-aligned fashion utilizing selective-epitaxial growth on porous silicon. As a result, some mask levels can be omitted, making this an inexpensive alternative to conventional processing.
    Type: Application
    Filed: November 8, 2006
    Publication date: May 29, 2008
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Thomas N. Adam, Thomas A. Wallner
  • Publication number: 20080121936
    Abstract: Embodiments herein present a structure, method, etc. for a self-alignment scheme for a heterojunction bipolar transistor (HBT). An HBT is provided, comprising an extrinsic base, a first self-aligned silicide layer over the extrinsic base, and a nitride etch stop layer above the first self-aligned silicide layer. A continuous layer is also included between the first self-aligned silicide layer and the nitride etch stop layer, wherein the continuous layer can comprise oxide. The HBT further includes spacers adjacent the continuous layer, wherein the spacers and the continuous layer separate the extrinsic base from an emitter contact. In addition, an emitter is provided, wherein the height of the emitter is less than or equal to the height of the extrinsic base. Moreover, a second self-aligned silicide layer is over the emitter, wherein the height of the second silicide layer is less than or equal to the height of the first silicide layer.
    Type: Application
    Filed: July 26, 2006
    Publication date: May 29, 2008
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Francois Pagette, Anna Topol
  • Publication number: 20080099788
    Abstract: The external base electrode has a two-layered structure where a p-type polysilicon film doped with a medium concentration of boron is laminated on a p-type polysilicon film doped with a high concentration of boron. Therefore, since the p-type polysilicon film doped with a high concentration of boron is in contact with an intrinsic base layer at a junction portion between the external base electrode and the intrinsic base layer, the resistance of the junction portion can be reduced. In addition, since the resistance of the external base electrode becomes a parallel resistance of the two layers of the p-type polysilicon films, the resistance of the p-type polysilicon film whose boron concentration is relatively lower is dominant.
    Type: Application
    Filed: October 31, 2007
    Publication date: May 1, 2008
    Inventors: Yoshinori Yoshida, Tatsuya Tominari, Toshio Ando
  • Patent number: 7358132
    Abstract: A self-aligned bipolar semiconductor device and a fabrication method thereof are provided. After a silicon layer and a collector contact are formed on a buried collector layer, an oxide dummy pattern is formed on the silicon layer to define both an extrinsic base and an intrinsic base. A polycide layer used as the extrinsic base is formed thereon and selectively removed to expose the dummy pattern. After the exposed dummy pattern is removed, an epitaxial layer used as the intrinsic base is grown on both the silicon layer and the polycide layer, and selectively removed from the top of the polycide layer. An oxide layer and a nitride layer are deposited in sequence thereon, and the nitride layer is blanket-etched to form spacers defining an emitter. After a photoresist pattern is formed to mostly cover the oxide layer and partly expose the oxide layer between the spacers over the intrinsic base, the oxide layer is etched by using the photoresist pattern and the spacers as an etch mask.
    Type: Grant
    Filed: December 30, 2005
    Date of Patent: April 15, 2008
    Assignee: Dongbu Electronics Co., Ltd.
    Inventor: Yeo Cho Yoon
  • Publication number: 20080078998
    Abstract: A semiconductor device (npn bipolar transistor) includes an n-type collector layer, a base layer constituted by a p+ diffusion layer, a SiGe layer and a p-type silicon film, an n-type emitter layer and a charge transport prevention film formed between the n-type collector layer and the n-type emitter layer and having an effect as a potential barrier with respect to either electrons or holes
    Type: Application
    Filed: September 24, 2007
    Publication date: April 3, 2008
    Inventors: Shinya Naito, Hideaki Fujiwara, Toru Dan
  • Publication number: 20080067631
    Abstract: The mobility of charge carriers in a bipolar (BJT) device is increased by creating compressive strain in the device to increase mobility of electrons in the device, and creating tensile strain in the device to increase mobility of holes in the device. The compressive and tensile strain are created by applying a stress film adjacent an emitter structure of the device and atop a base film of the device. In this manner, the compressive and tensile strain are located in close proximity to an intrinsic portion of the device. A suitable material for the stress film is nitride. The emitter structure may be “T-shaped”, having a lateral portion atop an upright portion, a bottom of the upright portion forms a contact to the base film, and the lateral portion overhangs the base film.
    Type: Application
    Filed: November 29, 2007
    Publication date: March 20, 2008
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Dureseti Chidambarrao, Gregory Freeman, Marwan Khater
  • Patent number: 7319061
    Abstract: In a method for fabricating an electronic device including a transistor with a drain extension structure, a correspondence between a size of a gate electrode of the transistor and ion implantation conditions or heat treatment conditions for forming the drain extension structure is previously obtained. This correspondence satisfies that the transistor has a given threshold voltage. After formation of the gate electrode and measurement of the size of the gate electrode, ion implantation conditions or heat treatment conditions for forming the drain extension structure are set based on the previously-obtained correspondence and the measured size of the gate electrode. Ion implantation or heat treatment for forming the drain extension structure is performed under the ion implantation conditions or heat treatment conditions that have been set.
    Type: Grant
    Filed: October 26, 2006
    Date of Patent: January 15, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Satoshi Shibata, Fumitoshi Kawase, Hisako Kamiyanagi, Emi Kanazaki
  • Publication number: 20070287234
    Abstract: Provided are bipolar transistor, BiCMOS device and method of fabricating thereof, in which an existing sub-collector disposed beneath a collector of a SiGe HBT is removed and a collector plug disposed at a lateral side of the collector is approached to a base when fabricating a Si-based very high-speed device, whereby it is possible to fabricate the SiGe HBT and an SOI CMOS on a single substrate, reduce the size of the device and the number of masks to be used, and implement the device of high density, low power consumption, and wideband performance.
    Type: Application
    Filed: April 30, 2007
    Publication date: December 13, 2007
    Inventors: Jin Kang, Seung Lee, Kyoung Cho
  • Patent number: 7297589
    Abstract: A method for making a heterojunction bipolar transistor includes the following steps: forming a heterojunction bipolar transistor by depositing, on a substrate, subcollector, collector, base, and emitter regions of semiconductor material; the step of depositing the subcollector region including depositing a material composition transition from a relatively larger bandgap material nearer the substrate to a relatively smaller bandgap material adjacent the collector; and the step of depositing the collector region including depositing a material composition transition from a relatively smaller bandgap material adjacent the subcollector to a relatively larger bandgap material adjacent the base.
    Type: Grant
    Filed: April 8, 2005
    Date of Patent: November 20, 2007
    Assignee: The Board of Trustees of The University of Illinois
    Inventor: Milton Feng
  • Publication number: 20070243689
    Abstract: A semiconductor device, able to be produced while suppressing the occurrence of mesa shaped abnormalities without restriction as to the pattern layout, the type of etchant used, etc., provided with a semiconductor mesa portion including a stack of a collector layer, a base layer, and an emitter layer on a substrate and functioning as an active region of a bipolar transistor, a base contact pad mesa portion separated from this by a predetermined distance and having a height the same as the top surface of the base layer, and a conductor layer integrally formed with a base electrode connected to the base layer, a base contact pad electrode formed on the base contact pad mesa portion in a region other than near the edges of the top surface of the base contact pad mesa portion, and an interconnect connecting these, and a method of producing the same.
    Type: Application
    Filed: March 20, 2007
    Publication date: October 18, 2007
    Applicant: Sony Corporation
    Inventor: Junichiro Kobayashi
  • Patent number: 7282416
    Abstract: In a method for fabricating an electronic device including a transistor with a drain extension structure, a correspondence between a size of a gate electrode of the transistor and ion implantation conditions or heat treatment conditions for forming the drain extension structure is previously obtained. This correspondence satisfies that the transistor has a given threshold voltage. After formation of the gate electrode and measurement of the size of the gate electrode, ion implantation conditions or heat treatment conditions for forming the drain extension structure are set based on the previously-obtained correspondence and the measured size of the gate electrode. Ion implantation or heat treatment for forming the drain extension structure is performed under the ion implantation conditions or heat treatment conditions that have been set.
    Type: Grant
    Filed: October 4, 2005
    Date of Patent: October 16, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Satoshi Shibata, Fumitoshi Kawase, Hisako Kamiyanagi, Emi Kanazaki
  • Publication number: 20070232008
    Abstract: In an npn-type HBT, each of an emitter layer and a collector layer is formed of AlGaN and a base layer is formed of GaN. The emitter layer is in contact with a nitrogen polarity surface of the base layer and the collector layer is in contact with a gallium polarity surface of the base layer. An electric charge is generated at each interface due to a spontaneous polarization and a piezo polarization generated in each of the layers. Because of the electric charge, an internal field is generated so as to accelerate electrons in the base layer.
    Type: Application
    Filed: May 11, 2007
    Publication date: October 4, 2007
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Satoshi Nakazawa, Yutaka Hirose, Tsuyoshi Tanaka
  • Patent number: 7242071
    Abstract: A structure comprises a deep sub-collector buried in a first epitaxial layer and a near sub-collector buried in a second epitaxial layer. The structure further comprises a deep trench isolation structure isolating a region which is substantially above the deep sub-collector, a reach-through structure in contact with the near sub-collector, and a reach-through structure in contact with the deep sub-collector to provide a low-resistance shunt, which prevents COMS latch-up of a device. The method includes forming a merged triple well double epitaxy/double sub-collector structure.
    Type: Grant
    Filed: July 6, 2006
    Date of Patent: July 10, 2007
    Assignee: International Business Machine Corporation
    Inventors: Xuefeng Liu, Robert M. Rassel, Steven H. Voldman
  • Patent number: 7202515
    Abstract: In the method for manufacturing a heterojunction bipolar transistor, a collector contact layer, a collector layer, a base layer, a base protection layer, an emitter layer, an emitter contact layer, and a WSi layer are sequentially formed on a substrate. A resist pattern is then formed on the WSi layer, and the WSi layer is patterned by using the resist pattern as a mask. Thereafter, the emitter contact layer and the emitter layer are sequentially removed by ICP (Inductively Coupled Plasma) dry etching by using the resist pattern as a mask.
    Type: Grant
    Filed: August 30, 2005
    Date of Patent: April 10, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hidenori Takeda, Toshiharu Tambo
  • Patent number: 7154118
    Abstract: A method of a bulk tri-gate transistor having stained enhanced mobility and its method of fabrication. The present invention is a nonplanar transistor having a strained enhanced mobility and its method of fabrication. The transistor has a semiconductor body formed on a semiconductor substrate wherein the semiconductor body has a top surface on laterally opposite sidewalls. A semiconductor capping layer is formed on the top surface and on the sidewalls of the semiconductor body. A gate dielectric layer is formed on the semiconductor capping layer on the top surface of a semiconductor body and is formed on the capping layer on the sidewalls of the semiconductor body. A gate electrode having a pair of laterally opposite sidewalls is formed on and around the gate dielectric layer. A pair of source/drain regions are formed in the semiconductor body on opposite sides of the gate electrode.
    Type: Grant
    Filed: March 31, 2004
    Date of Patent: December 26, 2006
    Assignee: Intel Corporation
    Inventors: Nick Lindert, Stephen M. Cea
  • Patent number: 7132701
    Abstract: Provided is a process for forming a contact for a compound semiconductor device without electrically shorting the device. In one embodiment, a highly doped compound semiconductor material is electrically connected to a compound semiconductor material of the same conductivity type through an opening in a compound semiconductor material of the opposite conductivity type. Another embodiment discloses a transistor including multiple compound semiconductor layers where a highly doped compound semiconductor material is electrically connected to a compound semiconductor layer of the same conductivity type through an opening in a compound semiconductor layer of the opposite conductivity type. Embodiments further include metal contacts electrically connected to the highly doped compound semiconductor material. A substantially planar semiconductor device is disclosed. In embodiments, the compound semiconductor material may be silicon carbide.
    Type: Grant
    Filed: July 27, 2001
    Date of Patent: November 7, 2006
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Martin E. Kordesch, Howard D. Bartlow, Richard L Woodin
  • Patent number: 7118981
    Abstract: In a method of fabricating an integrated silicon-germanium heterobipolar transistor a silicon dioxide layer arranged between a silicon-germanium base layer and a silicon emitter layer is formed by means of Rapid Thermal Processing (RTP) to ensure enhanced component properties of the integrated silicon-germanium heterobipolar transistor.
    Type: Grant
    Filed: April 15, 2004
    Date of Patent: October 10, 2006
    Assignee: Texas Instruments Incorporated
    Inventors: Alfred Haeusler, Philipp Steinmann, Scott Balster, Badih El-Kareh
  • Patent number: 6699741
    Abstract: A high frequency bipolar transistor that has a silicon germanium intrinsic base region is formed in a semiconductor fabrication process that forms the extrinsic base regions after the intrinsic base region has been formed. The extrinsic base regions are epitaxially grown single crystal silicon that is doped during the growth.
    Type: Grant
    Filed: August 16, 2002
    Date of Patent: March 2, 2004
    Assignee: National Semiconductor Corporation
    Inventors: Alexei Sadovnikov, Christopher John Knorr