Field Effect Device Patents (Class 257/20)
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Patent number: 8227807Abstract: By controlling the luminance of light emitting element not by means of a voltage to be impressed to the TFT but by means of controlling a current that flows to the TFT in a signal line drive circuit, the current that flows to the light emitting element is held to a desired value without depending on the characteristics of the TFT. Further, a voltage of inverted bias is impressed to the light emitting element every predetermined period. Since a multiplier effect is given by the two configurations described above, it is possible to prevent the luminance from deteriorating due to a deterioration of the organic luminescent layer, and further, it is possible to maintain the current that flows to the light emitting element to a desired value without depending on the characteristics of the TFT.Type: GrantFiled: September 7, 2010Date of Patent: July 24, 2012Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Mai Akiba, Jun Koyama
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Publication number: 20120145995Abstract: Disclosed herein are a nitride-based semiconductor device and a method for manufacturing the same. The nitride-based semiconductor device includes: a base substrate having a front surface and a rear surface opposite to the front surface; an epitaxial growth film formed on the front surface of the base substrate; a semiconductor layer formed on the rear surface of the base substrate; and an electrode structure body provided on the epitaxial growth film.Type: ApplicationFiled: March 16, 2011Publication date: June 14, 2012Inventors: Woochul Jeon, Kiyeol Park, Younghwan Park
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Patent number: 8193562Abstract: Enhancement mode III-nitride devices are described. The 2DEG is depleted in the gate region so that the device is unable to conduct current when no bias is applied at the gate. Both gallium face and nitride face devices formed as enhancement mode devices.Type: GrantFiled: February 1, 2011Date of Patent: June 5, 2012Assignee: Tansphorm Inc.Inventors: Chang Soo Suh, Umesh Mishra
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Patent number: 8193611Abstract: Material layer structures that have high mobility, a high conduction band barrier and materials that can be implanted to enable higher performance FET device. The structures contain a quantum well layer disposed between two barriers and disposed above a buffer layer and a substrate.Type: GrantFiled: December 19, 2006Date of Patent: June 5, 2012Assignee: HRL Laboratories, LLCInventors: Rajesh Rajavel, Ken Elliott, David Chow
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Patent number: 8188459Abstract: A nitride-based semiconductor device is provided. The nitride-base semiconductor device includes a substrate comprising one or more locally etched regions and a buffer layer comprising one or multiple InAlGaN layers on the substrate. A channel layer includes GaN on the buffer layer. A barrier layer includes one or multiple AlGaN layers on the channel layer.Type: GrantFiled: October 13, 2009Date of Patent: May 29, 2012Assignee: Massachusetts Institute of TechnologyInventors: Tomas Palacios, Jinwook Chung
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Patent number: 8183556Abstract: A CMOS device includes a PMOS transistor with a first quantum well structure and an NMOS device with a second quantum well structure. The PMOS and NMOS transistors are formed on a substrate.Type: GrantFiled: December 15, 2005Date of Patent: May 22, 2012Assignee: Intel CorporationInventors: Suman Datt{dot over (a)}, Mantu K. Hudait, Mark L. Doczy, Jack T. Kavalieros, Majumdar Amlan, Justin K. Brask, Been-Yih Jin, Matthew V. Metz, Robert S. Chau
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Patent number: 8183558Abstract: A compound semiconductor device includes a compound semiconductor substrate; epitaxially grown layers formed over the compound semiconductor substrate and including a channel layer and a resistance lowering cap layer above the channel layer; source and drain electrodes in ohmic contact with the channel layer; recess formed by removing the cap layer between the source and drain electrodes; a first insulating film formed on an upper surface of the cap layer and having side edges at positions retracted from edges, or at same positions as the edges of the cap layer in a direction of departing from the recess; a second insulating film having gate electrode opening and formed covering a semiconductor surface in the recess and the first insulating film; and a gate electrode formed on the recess via the gate electrode opening.Type: GrantFiled: February 8, 2011Date of Patent: May 22, 2012Assignee: Fujitsu LimitedInventors: Kozo Makiyama, Tsuyoshi Takahashi
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Patent number: 8178369Abstract: The present invention relates to a method of fabricating a nanoscale multi-junction quantum dot device wherein it can minimize constraints depending on the number or shape of patterns and a line width, and in particular, overcome shortcomings depending on the proximity effect occurring between patterns while employing the advantages of electron beam lithography to the utmost by forming a new conductive layer between the patterns and utilizing it as a new pattern.Type: GrantFiled: October 8, 2007Date of Patent: May 15, 2012Assignee: Nanochips, Inc.Inventors: Jung Bum Choi, Jong Jin Lee, Seung-Jun Shin, Rae-Sik Chung
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Patent number: 8164116Abstract: A semiconductor device includes: a semiconductor base; a hetero semiconductor region which is in contact with the semiconductor base and which has a band gap different from that of the semiconductor base; a first electrode connected to the hetero semiconductor region; and a second electrode forming an ohmic contact to the semiconductor base. The hetero semiconductor region includes a laminated hetero semiconductor region formed by laminating a plurality of semiconductor layers in which crystal alignment is discontinuous at a boundary between at least two layers.Type: GrantFiled: August 22, 2006Date of Patent: April 24, 2012Assignee: Nissan Motor Co., Ltd.Inventors: Tetsuya Hayashi, Yoshio Shimoida, Masakatsu Hoshi, Hideaki Tanaka, Shigeharu Yamagami
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Patent number: 8164086Abstract: A phase controllable field effect transistor device is described. The device provides first and second scattering sites disposed at either side of a conducting channel region, the conducting region being gated such that on application of an appropriate signal to the gate, energies of the electrons in the channel region defined between the scattering centers may be modulated.Type: GrantFiled: September 17, 2009Date of Patent: April 24, 2012Assignee: The Provost, Fellows and Scholars of the Colege of the Holy and Undivided Trinity of Queen Elizabeth Near DublinInventors: John Boland, Stefano Sanvito, Borislav Naydenov
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Patent number: 8154007Abstract: A mesoporous silica having adjustable pores is obtained to form a template and thus a three-terminal metal-oxide-semiconductor field-effect transistor (MOSFET) photodetector is obtained. A gate dielectric of a nano-structural silicon-base membrane is used as infrared light absorber in it. Thus, a semiconductor photodetector made of pure silicon having a quantum-dot structure is obtained with excellent near-infrared optoelectronic response.Type: GrantFiled: February 9, 2010Date of Patent: April 10, 2012Assignee: National Applied Research LaboratoriesInventors: Jia-Min Shieh, Wen-Chein Yu, Chao-Kei Wang, Bau-Tong Dai, Ci-Ling Pan, Hao-Chung Kuo, Jung-Y. Huang
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Patent number: 8129749Abstract: Double quantum well structures for transistors are generally described. In one example, an apparatus includes a semiconductor substrate, one or more buffer layers coupled to the semiconductor substrate, a first barrier layer coupled to the one or more buffer layers, a first quantum well channel coupled with the first barrier layer wherein the first quantum well channel includes a group III-V semiconductor material or a group II-VI semiconductor material, or combinations thereof, a second barrier layer coupled to the first quantum well channel, and a second quantum well channel coupled to the barrier layer wherein the second quantum well channel includes a group III-V semiconductor material or a group II-VI semiconductor material, or combinations thereof.Type: GrantFiled: March 28, 2008Date of Patent: March 6, 2012Assignee: Intel CorporationInventors: Ravi Pillarisetty, Mantu K. Hudait, Marko Radosavljevic, Gilbert Dewey, Titash Rakshit, Jack T. Kavalieros
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Patent number: 8115235Abstract: A quantum well (QW) layer is provided in a semiconductive device. The QW layer is provided with a beryllium-doped halo layer in a barrier structure below the QW layer. The semiconductive device includes InGaAs bottom and top barrier layers respectively below and above the QW layer. The semiconductive device also includes a high-k gate dielectric layer that sits on the InP spacer first layer in a gate recess. A process of forming the QW layer includes using an off-cut semiconductive substrate.Type: GrantFiled: February 20, 2009Date of Patent: February 14, 2012Assignee: Intel CorporationInventors: Ravi Pillarisetty, Titash Rakshit, Mantu Hudait, Marko Radosavljevic, Gilbert Dewey, Benjamin Chu-Kung
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Publication number: 20120032146Abstract: Embodiments of an apparatus and methods of providing a quantum well device for improved parallel conduction are generally described herein. Other embodiments may be described and claimed.Type: ApplicationFiled: October 17, 2011Publication date: February 9, 2012Inventors: Ravi Pillarisetty, Mantu Hudait, Been-Yin Jin, Benjamin Chu-Kung, Robert Chau
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Patent number: 8106424Abstract: A field effect transistor with a heterostructure includes a strained monocrystalline semiconductor layer formed on a carrier material, which has a relaxed monocrystalline semiconductor layer made of a first semiconductor material (Si) as the topmost layer. The strained monocrystalline semiconductor layer has a semiconductor alloy (GexSi1-x), where the proportion x of a second semiconductor material can be set freely. Furthermore, a gate insulation layer and a gate layer are formed on the strained semiconductor layer. To define an undoped channel region, drain/source regions are formed laterally with respect to the gate layer at least in the strained semiconductor layer. The possibility of freely setting the Ge proportion x enables a threshold voltage to be set as desired, whereby modern logic semiconductor components can be realized.Type: GrantFiled: August 20, 2010Date of Patent: January 31, 2012Assignee: Infineon Technologies AGInventor: Klaus Schruefer
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Publication number: 20120007049Abstract: The present invention provides a nitride-based semiconductor device. The nitride-based semiconductor device includes: a base substrate having a diode structure; an epi-growth film disposed on the base substrate; and an electrode part disposed on the epi-growth film, wherein the diode structure includes: first-type semiconductor layers; and a second-type semiconductor layer which is disposed within the first-type semiconductor layers and has both sides covered by the first-type semiconductor layers.Type: ApplicationFiled: November 2, 2010Publication date: January 12, 2012Inventors: Woo Chul JEON, Ki Yeol Park, Jung Hee Lee, Young Hwan Park
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Patent number: 8093644Abstract: A carbon nanotube based memory device comprises a set of three concentric carbon nanotubes having different diameters. The diameters of the three concentric carbon nanotubes are selected such that an inner carbon nanotube is semiconducting, and intershell electron transport occurs between adjacent carbon nanotubes. Source and drain contacts are made to the inner carbon nanotube, and a gate contact is made to the outer carbon nanotube. The carbon nanotube based memory device is programmed by storing electrons or holes in the middle carbon nanotube through intershell electron transport. Changes in conductance of the inner carbon nanotube due to the charge in the middle shell are detected to determine the charge state of the middle carbon nanotube. Thus, the carbon nanotube based memory device stores information in the middle carbon nanotube in the form of electrical charge.Type: GrantFiled: January 8, 2009Date of Patent: January 10, 2012Assignee: Internationl Business Machines CorporationInventor: Haining S. Yang
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Publication number: 20110316565Abstract: A Schottky junction silicon nanowire field-effect biosensor/molecule detector with a nanowire thickness of 10 nanometer or less and an aligned source/drain workfunction for increased sensitivity. The nanowire channel is coated with a surface treatment to which a molecule of interest absorbs, which modulates the conductivity of the channel between the Schottky junctions sufficiently to qualitatively and quantitatively measure the presence and amount of the molecule.Type: ApplicationFiled: June 29, 2010Publication date: December 29, 2011Applicant: International Business Machines Corp.Inventors: Dechao Guo, Christian Lavoie, Christine Qiqing Ouyang, Yanning Sun, Zhen Zhang
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Publication number: 20110309330Abstract: One, groups of several or many parallel vertical quantum wires arranged as 2-dimensional array interconnecting the source and drain of a transistor, are modulated with respect to their quantum-mechanical conductivity via the strength of an applied field. The Ohmic resistance of the source-drain connection via the quantum wire array is in the conducting state practically zero and the quantum wire field effect transistor's response time is solely determined by the switching time of the gate-field, which can be magnetic, electric, electroacoustic or optical. Applications for large arrays (>1010 parallel QWs) is a power transistor, for small arrays (single or few parallel QWs) it is non-volatile information-storage e.g. mediated via ferromagnetic/ferroelectric layers and/or nanoparticles, where due to the properties of 1-dimensional quantized conductivity multi-level logic is realized.Type: ApplicationFiled: March 3, 2009Publication date: December 22, 2011Inventor: Frank M. Ohnesorge
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Publication number: 20110278540Abstract: Provided is a field-effect transistor which is capable of suppressing current collapse. An HEMT as the field-effect transistor includes: a first semiconductor layer made of a first nitride semiconductor; and a second semiconductor layer formed on the first semiconductor layer and made of a second nitride semiconductor having a greater band gap than a band gap of the first nitride semiconductor, wherein the first semiconductor layer includes a region in which a threading dislocation density increases in a stacking direction.Type: ApplicationFiled: May 19, 2011Publication date: November 17, 2011Applicant: Panasonic CorporationInventors: Kenichiro Tanaka, Tetsuzo Ueda, Hisayoshi Matsuo, Masahiro Hikita
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Publication number: 20110233520Abstract: There is provided a semiconductor device including a base substrate; a semiconductor layer formed on the base substrate and having a mesa protrusion including a receiving groove; a source electrode and a drain electrode disposed to be spaced apart from each other on the semiconductor layer, the source electrode having a source leg and the drain electrode having a drain leg; and a gate electrode insulated from the source electrode and the drain electrode and having a recess part received into the receiving groove. The mesa protrusion has a superlattice structure including at least one trench at an interface between the mesa protrusion and the source electrode and between the mesa protrusion and the drain electrode, respectively, and the source leg and the drain leg are received in the trench.Type: ApplicationFiled: December 9, 2010Publication date: September 29, 2011Applicant: SAMSUNG ELECTRO-MECHANICS CO., LTD.Inventors: Woo Chul JEON, Ki Yeol Park, Young Hwan Park, Jung Hee Lee
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Patent number: 8026508Abstract: Provided are a semiconductor device and a method of fabricating the same. The semiconductor device includes: a single electron box including a first quantum dot, a charge storage gate on the first quantum dot, and a first gate electrode on the charge storage gate, the charge storage gate exchanging charges with the first quantum dot, the first gate electrode adjusting electric potential of the first quantum dot; and a single electron transistor including a second quantum dot below the first quantum dot, a source, a drain, and a second gate electrode below the second quantum dot, the second quantum dot being capacitively coupled to the first quantum dot, the source contacting one side of the second quantum dot, the drain contacting the other side facing the one side, the second gate electrode adjusting electric potential of the second quantum dot.Type: GrantFiled: July 7, 2009Date of Patent: September 27, 2011Assignee: Electronics and Telecommunications Research InstituteInventors: Myung-Sim Jun, Moon-Gyu Jang, Tae-Gon Noh, Tae-Moon Roh
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Patent number: 8022440Abstract: A compound semiconductor epitaxial substrate having a pseudomorphic high electron mobility field effect transistor structure including an InGaAs layer as a strained channel layer and an AlGaAs layer containing n type impurities as a front side electron-donating layer, wherein said substrate contains an InGaP layer in an orderly state on the front side of the above described InGaAs layer as the strained channel layer.Type: GrantFiled: February 4, 2004Date of Patent: September 20, 2011Assignee: Sumitomo Chemical Company, LimitedInventors: Tsuyoshi Nakano, Masahiko Hata
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Patent number: 8013407Abstract: There is provided a magnetic memory device stable in write characteristics. The magnetic memory device has a recording layer. The planar shape of the recording layer has the maximum length in the direction of the easy-axis over a primary straight line along the easy-axis, and is situated over a length smaller than the half of the maximum length in the direction perpendicular to the easy-axis, and on the one side and on the other side of the primary straight line respectively, the planar shape has a first part situated over a length in the direction perpendicular to the easy-axis, and a second part situated over a length smaller than the length in the direction perpendicular to the easy-axis. The outer edge of the first part includes only a smooth curve convex outwardly of the outer edge.Type: GrantFiled: March 6, 2009Date of Patent: September 6, 2011Assignee: Renesas Electronics CorporationInventors: Takashi Takenaga, Takeharu Kuroiwa, Hiroshi Takada, Shuichi Ueno, Kiyoshi Kawabata
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Patent number: 8003975Abstract: A semiconductor integrated circuit device includes: a semiconductor layer having a principal surface on which a source electrode, a drain electrode and a gate electrode are formed and having a first through hole; an insulating film formed in contact with the semiconductor layer and having a second through hole; a first interconnection formed on the semiconductor layer through the first through hole and connected to one of the source electrode, the drain electrode and the gate electrode which is exposed in the first through hole; and a second interconnection formed on the insulating film through the second through hole and connected to another of the source electrode, the drain electrode and the gate electrode which is exposed in the second through hole. The first interconnection and the second interconnection face each other and form a microstrip line.Type: GrantFiled: November 16, 2006Date of Patent: August 23, 2011Assignee: Panasonic CorporationInventors: Tetsuzo Ueda, Tsuyoshi Tanaka
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Patent number: 7973338Abstract: There is provided a hetero junction field effect transistor including: a first layer of a nitride based, group III-V compound semiconductor; a second layer of a nitride based, group III-V compound semiconductor containing a rare earth element, overlying the first layer; a pair of third layers of a nitride based, group III-V compound semiconductor, overlying the second layer, the third layers being spaced from each other; a gate electrode disposed between the third layers at least a region of the second layer; and a source electrode overlying one of the third layers and a drain electrode overlying an other of the third layers. A method of fabricating the hetero junction field effect transistor is also provided.Type: GrantFiled: July 22, 2009Date of Patent: July 5, 2011Assignee: Sharp Kabushiki KaishaInventor: Nobuaki Teraguchi
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Patent number: 7973304Abstract: A III-nitride semiconductor device which includes a barrier body between the gate electrode and the gate dielectric thereof.Type: GrantFiled: February 6, 2007Date of Patent: July 5, 2011Assignee: International Rectifier CorporationInventors: Robert Beach, Zhi He, Jianjun Cao
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Publication number: 20110147706Abstract: Embodiments of the present disclosure describe techniques and configurations to impart strain to integrated circuit devices such as horizontal field effect transistors. An integrated circuit device includes a semiconductor substrate, a first barrier layer coupled with the semiconductor substrate, a quantum well channel coupled to the first barrier layer, the quantum well channel comprising a first material having a first lattice constant, and a source structure coupled to the quantum well channel, the source structure comprising a second material having a second lattice constant, wherein the second lattice constant is different than the first lattice constant to impart a strain on the quantum well channel. Other embodiments may be described and/or claimed.Type: ApplicationFiled: December 23, 2009Publication date: June 23, 2011Inventors: Marko Radosavljevic, Gilbert Dewey, Niloy Mukherjee, Ravi Pillarisetty
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Patent number: 7964866Abstract: Embodiments of the invention relate to apparatus, system and method for use of a memory cell having improved power consumption characteristics, using a low-bandgap material quantum well structure together with a floating body cell.Type: GrantFiled: May 12, 2008Date of Patent: June 21, 2011Assignee: Intel CorporationInventors: Titash Rakshit, Gilbert Dewey, Ravi Pillarisetty
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Patent number: 7955881Abstract: In the method of fabricating a quantum well structure which includes a well layer and a barrier layer, the well layer is grown at a first temperature on a sapphire substrate. The well layer comprises a group III nitride semiconductor which contains indium as a constituent. An intermediate layer is grown on the InGaN well layer while monotonically increasing the sapphire substrate temperature from the first temperature. The group III nitride semiconductor of the intermediate layer has a band gap energy larger than the band gap energy of the InGaN well layer, and a thickness of the intermediate layer is greater than 1 nm and less than 3 nm in thickness. The barrier layer is grown on the intermediate layer at a second temperature higher than the first temperature. The barrier layer comprising a group III nitride semiconductor and the group III nitride semiconductor of the barrier layer has a band gap energy larger than the band gap energy of the well layer.Type: GrantFiled: July 9, 2009Date of Patent: June 7, 2011Assignee: Sumitomo Electric Industries, Ltd.Inventors: Katsushi Akita, Takamichi Sumitomo, Yohei Enya, Takashi Kyono, Masaki Ueno
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Patent number: 7928425Abstract: A semiconductor device which may include a semiconductor layer, and a superlattice interface layer therebetween. The superlattice interface layer may include a plurality of stacked groups of layers. Each group of layers may include a plurality of stacked base semiconductor monolayers defining a base semiconductor portion, and at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions. At least some atoms from opposing base semiconductor portions may be chemically bound together with the chemical bonds traversing the at least one intervening non-semiconductor monolayer.Type: GrantFiled: January 23, 2008Date of Patent: April 19, 2011Assignee: Mears Technologies, Inc.Inventor: Kalipatnam Vivek Rao
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Patent number: 7924107Abstract: A resonant tunneling structure for generating oscillation with multiple fundamental oscillation frequencies is provided. A first quantum well layer has a second sub-band (E2). A second quantum well layer has a first sub-band (E1) and a third sub-band (E3). When no electric field is applied, the resonant tunneling structure satisfies “(Eb1, Eb2)<E1<E2<E3”, where band edge energies of a first and second electrical contact layers relative to a carrier are expressed by Eb1 and Eb2, respectively. When a first electric field (Va) is applied, a resonant tunneling phenomenon is caused by the third sub-band and the second sub-band. When a second electric field (Vb) different in polarity from the first electric field is applied, a resonant tunneling phenomenon is caused by the second sub-band and the first sub-band.Type: GrantFiled: October 23, 2008Date of Patent: April 12, 2011Assignee: Canon Kabushiki KaishaInventors: Yasushi Koyama, Ryota Sekiguchi
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Patent number: 7915643Abstract: Enhancement mode III-nitride devices are described. The 2DEG is depleted in the gate region so that the device is unable to conduct current when no bias is applied at the gate. Both gallium face and nitride face devices formed as enhancement mode devices.Type: GrantFiled: September 17, 2007Date of Patent: March 29, 2011Assignee: Transphorm Inc.Inventors: Chang Soo Suh, Umesh Mishra
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Patent number: 7915640Abstract: 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: GrantFiled: May 19, 2006Date of Patent: March 29, 2011Assignee: Sony CorporationInventor: Masaya Uemura
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Patent number: 7902012Abstract: A method for forming and the structure of a strained lateral channel of a field effect transistor, a field effect transistor and CMOS circuitry is described incorporating a drain, body and source region on a single crystal semiconductor substrate wherein a hetero-junction is formed between the source and body of the transistor, wherein the source region and channel are independently lattice strained with respect the body region. The invention reduces the problem of leakage current from the source region via the hetero junction and lattice strain while independently permitting lattice strain in the channel region for increased mobility via choice of the semiconductor materials and alloy composition.Type: GrantFiled: August 3, 2009Date of Patent: March 8, 2011Assignee: International Business Machines CorporationInventors: Qiqing Christine Ouyang, Jack Oon Chu
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Patent number: 7884393Abstract: Affords high electron mobility transistors having a high-purity channel layer and a high-resistance buffer layer. A high electron mobility transistor (11) is provided with a supporting substrate (13) composed of gallium nitride, a buffer layer (15) composed of a first gallium nitride semiconductor, a channel layer (17) composed of a second gallium nitride semiconductor, a semiconductor layer (19) composed of a third gallium nitride semiconductor, and electrode structures (a gate electrode (21), a source electrode (23) and a drain electrode (25) for the transistor (11). The band gap of the third gallium nitride semiconductor is broader than that of the second gallium nitride semiconductor. The carbon concentration NC1 of the first gallium nitride semiconductor is 4×1017 cm?3 or more. The carbon concentration NC2 of the second gallium nitride semiconductor is less than 4×1016 cm?3.Type: GrantFiled: May 25, 2010Date of Patent: February 8, 2011Assignee: Sumitomo Electric Industries, Ltd.Inventors: Shin Hashimoto, Makoto Kiyama, Takashi Sakurada, Tatsuya Tanabe, Kouhei Miura, Tomihito Miyazaki
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Patent number: 7858965Abstract: The present invention generally relates to nanoscale heterostructures and, in some cases, to nanowire heterostructures exhibiting ballistic transport, and/or to metal-semiconductor junctions that that exhibit no or reduced Schottky barriers. One aspect of the invention provides a solid nanowire having a core and a shell, both of which are essentially undoped. For example, in one embodiment, the core may consist essentially of undoped germanium and the shell may consist essentially of undoped silicon. Carriers are injected into the nanowire, which can be ballistically transported through the nanowire. In other embodiments, however, the invention is not limited to solid nanowires, and other configurations, involving other nanoscale wires, are also contemplated within the scope of the present invention. Yet another aspect of the invention provides a junction between a metal and a nanoscale wire that exhibit no or reduced Schottky barriers.Type: GrantFiled: May 25, 2007Date of Patent: December 28, 2010Assignee: President and Fellows of Harvard CollegeInventors: Wei Lu, Jie Xiang, Yue Wu, Brian P. Timko, Hao Yan, Charles M. Lieber
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Patent number: 7858964Abstract: A semiconductor device includes a substrate that includes a first layer and a recrystallized layer on the first layer. The first layer has a first intrinsic stress and the recrystallized layer has a second intrinsic stress. A transistor is formed in the recrystallized layer. The transistor includes a source region, a drain region, and a charge carrier channel between the source and drain regions. The second intrinsic stress is aligned substantially parallel to the charge carrier channel.Type: GrantFiled: February 9, 2009Date of Patent: December 28, 2010Assignee: Infineon Technologies AGInventors: Roman Knoefler, Armin Tilke
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Patent number: 7851783Abstract: A method of fabricating a nanotube field-effect transistor having unipolar characteristics and a small inverse sub-threshold slope includes forming a local gate electrode beneath the nanotube between drain and source electrodes of the transistor and doping portions of the nanotube. In a further embodiment, the method includes forming at least one trench in the gate dielectric (e.g., a back gate dielectric) and back gate adjacent to the local gate electrode. Another aspect of the invention is a nanotube field-effect transistor fabricated using such a method.Type: GrantFiled: June 30, 2008Date of Patent: December 14, 2010Assignee: International Business Machines CorporationInventors: Joerg Appenzeller, Phaedon Avouris, Yu-Ming Lin
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Patent number: 7847282Abstract: The disclosed embodiments relate to a vertical tunneling transistor that may include a channel disposed on a substrate. A quantum dot may be disposed so that an axis through the channel and the quantum dot is substantially perpendicular to the substrate. A gate may be disposed so that an axis through the channel, the quantum dot and the gate is substantially perpendicular to the substrate.Type: GrantFiled: August 13, 2008Date of Patent: December 7, 2010Assignee: Micron Technologies, IncInventor: Gurtej S. Sandhu
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Patent number: 7847281Abstract: A first film made of SiGe is formed over a support substrate whose surface layer is made of Si. A gate electrode is formed over a partial area of the first film, and source and drain regions are formed in the surface layer of the support substrate on both sides of the gate electrode. The gate electrode and source and drain regions constitute a first field effect transistor. A first stressor internally containing compressive strain or tensile strain is formed over the first film on both sides of the gate electrode of the first field effect transistor. The first stressor forms strain in a channel region.Type: GrantFiled: March 28, 2008Date of Patent: December 7, 2010Assignee: Fujitsu LimitedInventors: Takashi Mimura, Atsushi Yamada
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Patent number: 7829883Abstract: Carbon nanotube field effect transistors, arrays of carbon nanotube field effect transistors, device structures, and arrays of device structures. A stacked device structure includes a gate electrode layer and catalyst pads each coupled electrically with a source/drain contact. The gate electrode layer is divided into multiple gate electrodes and at least one semiconducting carbon nanotube is synthesized by a chemical vapor deposition process on each of the catalyst pads. The gate electrode has a sidewall covered by a gate dielectric and at least one semiconducting carbon nanotube adjacent to the sidewall of the gate electrode. Source/drain contacts are electrically coupled with opposite ends of the semiconducting carbon nanotube to complete the device structure. Multiple device structures may be configured either as a memory circuit or as a logic circuit.Type: GrantFiled: February 12, 2004Date of Patent: November 9, 2010Assignee: International Business Machines CorporationInventors: Toshiharu Furukawa, Mark Charles Hakey, Steven John Holmes, David Vaclav Horak, Charles William Koburger, III, Peter H. Mitchell, Larry Alan Nesbit
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Patent number: 7825399Abstract: An optical device comprising: a first active stack of layers comprising an optical cavity, at least one quantum dot located in said cavity; an upper contact provided above said optical cavity; a lower contact provided below said cavity, wherein an abrupt material interface defines the whole lateral boundary of said cavity and said cavity is patterned such that it provides two dimensional lateral confinement of photon modes, said upper an lower contacts being arranged such that current can flow vertically across the cavity between the two contacts.Type: GrantFiled: March 11, 2005Date of Patent: November 2, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Patrick Un Siong See, Andrew James Shields
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Publication number: 20100270535Abstract: A method for making an electronic device may include forming a selectively polable superlattice comprising a plurality of stacked groups of layers. Each group of layers of the selectively polable superlattice may include a plurality of stacked semiconductor monolayers defining a semiconductor base portion and at least one non-semiconductor monolayer thereon. The at least one non-semiconductor monolayer may be constrained within a crystal lattice of adjacent silicon portions, and at least some semiconductor atoms from opposing base semiconductor portions may be chemically bound together through the at least one non-semiconductor monolayer therebetween. The method may further include coupling at least one electrode to the selectively polable superlattice for selective poling thereof.Type: ApplicationFiled: May 18, 2010Publication date: October 28, 2010Applicant: Mears Technologies, Inc.Inventors: Samed Halilov, Xiangyang Huang, Ilija Dukovski, Jean Augustin Chan Sow Fook Yiptong, Robert J. Mears, Marek Hytha, Robert John Stephenson
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Patent number: 7821031Abstract: A switch circuit includes: a first FET that is connected to one of an input terminal and an output terminal, and performs ON/OFF operation under the control of a gate electrode connected to a control terminal; and a second FET that is connected between the first FET and the other one of the input terminal and the output terminal, and performs ON/OFF operation under the control of a gate electrode connected to the control terminal. The first FET has a higher gate backward breakdown voltage than that of the second FET. Alternatively, the first FET has lower OFF capacitance than that of the second FET.Type: GrantFiled: March 29, 2006Date of Patent: October 26, 2010Assignee: Eudyna Devices Inc.Inventor: Hajime Matsuda
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Publication number: 20100243989Abstract: A semiconductor device includes a substrate, a superlattice buffer layer that is formed on the substrate and is composed of first AlxGa1-xN layers and second AlxGa1-xN layers having an Al composition greater than that of the first AlxGa1-xN layers, the first and second AlxGa1-xN layers being alternately stacked one by one, both the Al compositions of the first and second AlxGa1-xN layers being greater than 0.3, and a difference in Al composition between the first and second AlxGa1-xN layers being greater than 0 and smaller than 0.6.Type: ApplicationFiled: March 25, 2010Publication date: September 30, 2010Applicant: SUMITOMO ELECTRIC DEVICE INNOVATIONS, INC.Inventors: Isao Makabe, Ken Nakata
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Patent number: 7800097Abstract: A semiconductor device includes a semiconductor substrate of n-type silicon including, in an upper portion thereof, a first polarity inversion region and a second polarity inversion regions spaced from each other and doped with a p-type impurity. A first HFET including a first active layer and a second HFET including a second active layer both made of a group III-V nitride semiconductor are independently formed on the respective polarity inversion regions in the semiconductor substrate, and the HFETs are electrically connected to each other through interconnects.Type: GrantFiled: December 13, 2005Date of Patent: September 21, 2010Assignee: Panasonic CorporationInventors: Yutaka Hirose, Tsuyoshi Tanaka
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Patent number: 7799647Abstract: A method of forming a semiconductor structure includes forming a channel layer; forming a superlattice barrier layer overlying the channel layer, and forming a gate dielectric overlying the superlattice barrier layer. The superlattice barrier layer includes alternating first and second layers of barrier material. In addition, the superlattice barrier layer is configured for increasing a transconductance of the semiconductor device by at least a factor of three over a semiconductor device absent such superlattice barrier layer.Type: GrantFiled: July 31, 2007Date of Patent: September 21, 2010Assignee: Freescale Semiconductor, Inc.Inventors: Ravindranath Droopad, Matthias Passlack, Karthik Rajagopalan
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Patent number: 7795622Abstract: A compound semiconductor device having a transistor structure, includes a substrate, a first layer formed on the substrate and comprising GaN, a second layer formed over the first layer and containing InN whose lattice constant is larger than the first layer, a third layer formed over the second layer and comprising GaN whose energy bandgap is smaller than the second layer, and a channel region layer formed on the third layer.Type: GrantFiled: March 31, 2008Date of Patent: September 14, 2010Assignee: Fujitsu LimitedInventors: Toshihide Kikkawa, Kenji Imanishi
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Publication number: 20100224861Abstract: A field-effect transistor is provided and includes source, gate and drain regions, where the gate region controls charge carrier location in the transport channel, the transport channel includes a asymmetric coupled quantum well layer, the asymmetric quantum well layer includes at least two quantum wells separated by a barrier layer having a greater energy gap than the wells, the transport channel is connected to the source region at one end, and the drain regions at the other, the drain regions include at least two contacts electrically isolated from each other, the contacts are connected to at least one quantum well. The drain may include two regions that are configured to form the asymmetric coupled well transport channel. In an embodiment, two sources and two drains are also envisioned.Type: ApplicationFiled: January 4, 2010Publication date: September 9, 2010Inventors: Faquir Chand Jain, Evan Heller