Strained Layer Superlattice Patents (Class 257/18)
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Patent number: 8723161Abstract: A two-color detector includes a first absorber layer. The first absorber layer exhibits a first valence band energy characterized by a first valence band energy function. A barrier layer adjoins the first absorber layer at a first interface. The barrier layer exhibits a second valence band energy characterized by a second valence band energy function. The barrier layer also adjoins a second absorber layer at a second interface. The second absorber layer exhibits a third valence band energy characterized by a third valence band energy function. The first and second valence band energy functions are substantially functionally or physically continuous at the first interface and the second and third valence band energy functions are substantially functionally or physically continuous at the second interface.Type: GrantFiled: January 17, 2012Date of Patent: May 13, 2014Assignee: Sandia CorporationInventors: John F. Klem, Jin K. Kim
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Patent number: 8723165Abstract: A vertical electro-optical component and a method for forming the same are provided. The vertical electro-optical component includes a substrate, a first electrode layer formed on the substrate, a patterned insulating layer formed on the first electrode layer, a metal layer formed on the patterned insulating layer, a semiconductor layer formed on the first electrode layer, and a second electrode layer formed on the semiconductor layer, wherein the semiconductor layer encapsulates the patterned insulating layer and the metal layer. The vertical electro-optical component thus has a low operational voltage of a vertical transistor and a high reaction speed of a photo diode, and may be used to form light-emitting transistors.Type: GrantFiled: May 19, 2011Date of Patent: May 13, 2014Assignee: National Chiao Tung UniversityInventors: Hsiao-Wen Zan, Hsin-Fei Meng, Wu-Wei Tsai, Yu-Chiang Chao
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Patent number: 8710489Abstract: To provide an epitaxial substrate for electronic devices, in which current flows in a lateral direction, which enables accurate measurement of the sheet resistance of HEMTs without contact, and to provide a method of efficiently producing the epitaxial substrate for electronic devices, the method characteristically includes the steps of forming a barrier layer against impurity diffusion on one surface of a high-resistance Si-single crystal substrate, forming a buffer as an insulating layer on the other surface of the high-resistance Si-single crystal substrate, producing an epitaxial substrate by epitaxially growing a plurality of III-nitride layers on the buffer to form a main laminate, and measuring resistance of the main laminate of the epitaxial substrate without contact.Type: GrantFiled: July 13, 2010Date of Patent: April 29, 2014Assignee: Dowa Electronics Materials Co., Ltd.Inventors: Tetsuya Ikuta, Daisuke Hino, Ryo Sakamoto, Tomohiko Shibata
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Publication number: 20140103294Abstract: 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 quantum well channel coupled with the semiconductor substrate, a source structure coupled with the quantum well channel, a drain structure coupled with the quantum well channel and a strain-inducing film disposed on and in direct contact with material of the source structure and the drain structure to reduce resistance of the quantum well channel by imparting a tensile or compressive strain on the quantum well channel, wherein the quantum well channel is disposed between the strain-inducing film and the semiconductor substrate. Other embodiments may be described and/or claimed.Type: ApplicationFiled: December 13, 2013Publication date: April 17, 2014Inventors: Marko Radosavljevic, Gilbert Dewey, Niloy Mukherjee, Ravi Pillarisetty
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Patent number: 8698127Abstract: A superlattice layer including a plurality of periods, each of which is formed from a plurality of sub-layers is provided. Each sub-layer comprises a different composition than the adjacent sub-layer(s) and comprises a polarization that is opposite a polarization of the adjacent sub-layer(s). In this manner, the polarizations of the respective adjacent sub-layers compensate for one another.Type: GrantFiled: January 8, 2011Date of Patent: April 15, 2014Assignee: Sensor Electronic Technology, Inc.Inventors: Michael Shur, Remigijus Gaska, Jinwei Yang
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Patent number: 8669585Abstract: A strain release layer adjoining the active layer in a blue LED is bounded on the bottom by a first relatively-highly silicon-doped region and is also bounded on the top by a second relatively-highly silicon-doped region. The second relatively-highly silicon-doped region is a sublayer of the active layer of the LED. The first relatively-highly silicon-doped region is a sublayer of the N-type layer of the LED. The first relatively-highly silicon-doped region is also separated from the remainder of the N-type layer by an intervening sublayer that is only lightly doped with silicon. The silicon doping profile promotes current spreading and high output power (lumens/watt). The LED has a low reverse leakage current and a high ESD breakdown voltage. The strain release layer has a concentration of indium that is between 5×1019 atoms/cm3 and 5×102° atoms/cm3, and the first and second relatively-highly silicon-doped regions have silicon concentrations that exceed 1×1018 atoms/cm3.Type: GrantFiled: September 1, 2012Date of Patent: March 11, 2014Assignee: Toshiba Techno Center Inc.Inventors: Zhen Chen, Yi Fu
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Patent number: 8642413Abstract: A method to form a strain-inducing epitaxial film is described. In one embodiment, the strain-inducing epitaxial film is a three-component epitaxial film comprising atoms from a parent film, charge-neutral lattice-substitution atoms and charge-carrier dopant impurity atoms. In another embodiment, the strain-inducing epitaxial film is formed by a multiple deposition/etch cycle sequence involving hydrogenated amorphous silicon, followed by charge carrier dopant and charge-neutral lattice-forming impurity atom implant steps and, finally, a kinetically-driven crystallization process.Type: GrantFiled: September 14, 2006Date of Patent: February 4, 2014Assignee: Intel CorporationInventors: Anand S. Murthy, Jeffrey L. Armstrong, Dennis G. Hanken
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Patent number: 8642434Abstract: While embedded silicon germanium alloy and silicon carbon alloy provide many useful applications, especially for enhancing the mobility of MOSFETs through stress engineering, formation of alloyed silicide on these surfaces degrades device performance. The present invention provides structures and methods for providing unalloyed silicide on such silicon alloy surfaces placed on semiconductor substrates. This enables the formation of low resistance contacts for both mobility enhanced PFETs with embedded SiGe and mobility enhanced NFETs with embedded Si:C on the same semiconductor substrate. Furthermore, this invention provides methods for thick epitaxial silicon alloy, especially thick epitaxial Si:C alloy, above the level of the gate dielectric to increase the stress on the channel on the transistor devices.Type: GrantFiled: February 16, 2012Date of Patent: February 4, 2014Assignee: International Business Machines CorporationInventors: Yaocheng Liu, Dureseti Chidambarrao, Oleg Gluschenkov, Judson R. Holt, Renee T. Mo, Kern Rim
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Patent number: 8633573Abstract: Various applications are directed to a material stack having a strained active material therein. In connection with an embodiment, an active material (e.g. a semiconductor material) is at least initially and partially released from and suspended over a substrate, strained, and held in place. The release and suspension facilitates the application of strain to the semiconductor material.Type: GrantFiled: February 16, 2010Date of Patent: January 21, 2014Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: Jinendra Raja Jain, Roger T. Howe
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Patent number: 8633470Abstract: 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: GrantFiled: December 23, 2009Date of Patent: January 21, 2014Assignee: Intel CorporationInventors: Marko Radosavljevic, Gilbert Dewey, Niloy Mukherjee, Ravi Pillarisetty
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Patent number: 8629426Abstract: Various source/drain stressors that can enhance carrier mobility, and methods for manufacturing the same, are disclosed. An exemplary source/drain stressor includes a seed layer of a first material disposed over a substrate of a second material, the first material being different than the second material; a relaxed epitaxial layer disposed over the seed layer; and an epitaxial layer disposed over the relaxed epitaxial layer.Type: GrantFiled: December 3, 2010Date of Patent: January 14, 2014Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.Inventors: Chin-Hsiang Lin, Jeff J. Xu, Pang-Yen Tsai
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Publication number: 20140001438Abstract: A semiconductor device includes a buffer structure on a silicon substrate, and at least one gallium nitride-based semiconductor layer on the buffer structure. The buffer structure includes a plurality of nitride semiconductor layers and a plurality of stress control layers that are alternately disposed with the plurality of nitride semiconductor layer. The plurality of stress control layers include a IV-IV group semiconductor material.Type: ApplicationFiled: March 15, 2013Publication date: January 2, 2014Inventors: Joo-sung KIM, Jun-youn KIM, Jae-won LEE, Hyo-ji CHOI, Young-jo TAK
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Patent number: 8617968Abstract: A method of forming a semiconductor device that includes providing a first strained layer of a first composition semiconductor material over a dielectric layer. A first portion of the layer of the first composition semiconductor material is etched or implanted to form relaxed islands of the first composition semiconductor material. A second composition semiconductor material is epitaxially formed over the relaxed island of the first composition semiconductor material. The second composition semiconductor material is intermixed with the relaxed islands of the first composition semiconductor material to provide a second strained layer having a different strain than the first strained layer.Type: GrantFiled: June 18, 2012Date of Patent: December 31, 2013Assignee: International Business Machines CorporationInventors: Kangguo Cheng, Bruce B. Doris, Pouya Hashemi, Ali Khakifirooz
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Publication number: 20130334496Abstract: A semiconductor device includes a silicon substrate; a nitride nucleation layer disposed on the silicon substrate; at least one superlattice layer disposed on the nitride nucleation layer; and at least one gallium nitride-based semiconductor layer disposed on the superlattice layer. The at least one superlattice layer includes a stack of complex layers, each complex layer including a first layer and a second layer such that each of the complex layers has a plurality of nitride semiconductor layers having different compositions, at least one of the plurality of nitride semiconductor layers having a different thickness based on a location of the at least one nitride semiconductor layer within the stack, and at least one stress control layer having a thickness greater than a critical thickness for pseudomorphic growth.Type: ApplicationFiled: March 15, 2013Publication date: December 19, 2013Inventors: Jae-kyun KIM, Jun-youn KIM, Young-jo TAK
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Patent number: 8598566Abstract: The present disclosure generally relates to techniques for controlled quantum dot growth as well as a quantum dot structures. In some examples, a method is described that includes one or more of providing a substrate, forming a defect on the substrate, depositing a layer on the substrate and forming quantum dots along the defect.Type: GrantFiled: November 10, 2011Date of Patent: December 3, 2013Assignee: Empire Technology Development LLCInventor: Ezekiel Kruglick
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Patent number: 8575595Abstract: A semiconductor device comprises an active layer above a first confinement layer. The active layer comprises a layer of ?-Sn less than 20 nm thick. The first confinement layer is formed of material with a wider band gap than ?-Sn, wherein the band gap offset between ?-Sn and this material allows confinement of charge carriers in the active layer so that the active layer acts as a quantum well. A similar second confinement layer may be formed over the active layer. This semiconductor device may be a p-FET. A method of fabricating such a semiconductor device is described.Type: GrantFiled: April 12, 2010Date of Patent: November 5, 2013Assignee: Qinetiq LimitedInventor: David John Wallis
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Patent number: 8558290Abstract: Disclosed herein are various semiconductor devices with dual metal silicide regions and to various methods of making such devices. In one example, the device includes a gate electrode and a plurality of source/drain regions formed in a substrate proximate the gate electrode structure. The device further includes a first metal silicide region formed in each of the source/drain regions, wherein the first metal silicide region has an inner boundary and a second metal silicide region formed in each of the source/drain regions, wherein the second metal silicide region is positioned laterally between the inner boundary of the first metal silicide region and an edge of the gate electrode structure.Type: GrantFiled: August 25, 2011Date of Patent: October 15, 2013Assignee: GLOBALFOUNDRIES Inc.Inventors: Thilo Scheiper, Stefan Flachowsky
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Patent number: 8541771Abstract: Example embodiments relate to a semiconductor device and a method of manufacturing the semiconductor device. The semiconductor device may include a pre-seeding layer and a nucleation layer. The pre-seeding layer may include a first material for pre-seeding and a second material for masking so as to reduce tensile stress.Type: GrantFiled: June 10, 2011Date of Patent: September 24, 2013Assignee: Samsung Electronics Co., Ltd.Inventors: Jun-youn Kim, Su-hee Chae, Hyun-gi Hong, Young-jo Tak
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Publication number: 20130234113Abstract: Embodiments described include straining transistor quantum well (QW) channel regions with metal source/drains, and conformal regrowth source/drains to impart a uni-axial strain in a MOS channel region. Removed portions of a channel layer may be filled with a junction material having a lattice spacing different than that of the channel material to causes a uni-axial strain in the channel, in addition to a bi-axial strain caused in the channel layer by a top barrier layer and a bottom buffer layer of the quantum well.Type: ApplicationFiled: April 25, 2013Publication date: September 12, 2013Inventors: Prashant Majhi, Mantu K. Hudait, Jack T. Kavalieros, Ravi Pillarisetty, Marko Radosavljevic, Gilbert Dewey, Titash Rakshit, Willman Tsai
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Patent number: 8530257Abstract: Methods for improving the temperature performance of AlInGaP based light emitters. Nitrogen is added to the quantum wells in small quantities. Nitrogen is added in a range of about 0.5 percent to 2 percent. The addition of nitrogen increases the conduction band offset and increases the separation of the indirect conduction band. To keep the emission wavelength in a particular range, the concentration of In in the quantum wells may be decreased or the concentration of Al in the quantum wells may be increased. The net result is an increase in the conduction band offset and an increase in the separation of the indirect conduction band.Type: GrantFiled: August 27, 2012Date of Patent: September 10, 2013Assignee: Finisar CorporationInventor: Ralph Herbert Johnson
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Publication number: 20130221327Abstract: A semiconductor structure includes a substrate, a nucleation layer on the substrate, a compositionally graded layer on the nucleation layer, and a layer of a nitride semiconductor material on the compositionally graded layer. The layer of nitride semiconductor material includes a plurality of substantially relaxed nitride interlayers spaced apart within the layer of nitride semiconductor material. The substantially relaxed nitride interlayers include aluminum and gallium and are conductively doped with an n-type dopant, and the layer of nitride semiconductor material including the plurality of nitride interlayers has a total thickness of at least about 2.0 ?m.Type: ApplicationFiled: January 28, 2013Publication date: August 29, 2013Applicant: Cree, Inc.Inventor: Cree, Inc.
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Patent number: 8502284Abstract: The semiconductor device includes a silicon substrate having a channel region, a gate electrode formed over the channel region, buried semiconductor regions formed in a surface of the silicon substrate on both sides of the gate electrode, for applying to the surface of the silicon substrate a first stress in a first direction parallel to the surface of the silicon substrate, and stressor films formed on the silicon substrate between the channel region and the buried semiconductor regions in contact with the silicon substrate, for applying to the silicon substrate a second stress in a second direction which is opposite to the first direction.Type: GrantFiled: June 30, 2009Date of Patent: August 6, 2013Assignee: Fujitsu Semiconductor LimitedInventor: Naoyoshi Tamura
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Patent number: 8497528Abstract: A structure for a field effect transistor on a substrate that includes a gate stack, an isolation structure and a source/drain (S/D) recess cavity below the top surface of the substrate disposed between the gate stack and the isolation structure. The recess cavity having a lower portion and an upper portion. The lower portion having a first strained layer and a first dielectric film. The first strained layer disposed between the isolation structure and the first dielectric film. A thickness of the first dielectric film less than a thickness of the first strained layer. The upper portion having a second strained layer overlying the first strained layer and first dielectric film.Type: GrantFiled: May 6, 2010Date of Patent: July 30, 2013Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.Inventors: Tsung-Lin Lee, Chih-Hao Chang, Chih-Hsin Ko, Feng Yuan, Jeff J. Xu
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Patent number: 8487295Abstract: Methods of fabricating semiconductor structures and devices include bonding a seed structure to a substrate using a glass. The seed structure may comprise a crystal of semiconductor material. Thermal treatment of the seed structure bonded to the substrate using the glass may be utilized to control a strain state within the seed structure. The seed structure may be placed in a state of compressive strain at room temperature. The seed structure bonded to the substrate using the glass may be used for growth of semiconductor material, or, in additional methods, a seed structure may be bonded to a first substrate using a glass, thermally treated to control a strain state within the seed structure and a second substrate may be bonded to an opposite side of the seed structure using a non-glassy material.Type: GrantFiled: January 4, 2012Date of Patent: July 16, 2013Assignee: SoitecInventor: Fabrice Letertre
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Patent number: 8466520Abstract: In a transistor, a strain-inducing semiconductor alloy, such as silicon/germanium, silicon/carbon and the like, may be positioned very close to the channel region by providing gradually shaped cavities which may then be filled with the strain-inducing semiconductor alloy. For this purpose, two or more “disposable” spacer elements of different etch behavior may be used in order to define different lateral offsets at different depths of the corresponding cavities. Consequently, enhanced uniformity and, thus, reduced transistor variability may be accomplished, even for sophisticated semiconductor devices.Type: GrantFiled: May 14, 2012Date of Patent: June 18, 2013Assignee: Advanced Micro Devices, Inc.Inventors: Stephan Kronholz, Vassilios Papageorgiou, Gunda Beernink
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Patent number: 8455858Abstract: A semiconductor structure is provided. The semiconductor structure may include a substrate (100); a buffer layer or an insulation layer (200) formed on the substrate; a first strained wide bandgap semiconductor material layer (400) formed on the buffer layer or the insulation layer; a strained narrow bandgap semiconductor material layer (500) formed on the first strained wide bandgap semiconductor material layer; a second strained wide bandgap semiconductor material layer (700) formed on the strained narrow bandgap semiconductor material layer; a gate stack (300) formed on the second strained wide bandgap semiconductor material layer; and a source and a drain (600) formed in the first strained wide bandgap semiconductor material layer, the strained narrow bandgap semiconductor material layer and the second strained wide bandgap semiconductor material layer respectively.Type: GrantFiled: November 8, 2010Date of Patent: June 4, 2013Assignee: Tsinghua UniversityInventors: Jing Wang, Jun Xu, Lei Guo
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Patent number: 8436336Abstract: The invention provides semiconductor structure comprising a strained Ge channel layer, and a gate dielectric disposed over the strained Ge channel layer. In one aspect of the invention, a strained Ge channel MOSFET is provided. The strained Ge channel MOSFET includes a relaxed SiGe virtual substrate with a Ge content between 50-95%, and a strained Ge channel formed on the virtual substrate. A gate structure is formed upon the strained Ge channel, whereupon a MOSFET is formed with increased performance over bulk Si. In another embodiment of the invention, a semiconductor structure comprising a relaxed Ge channel layer and a virtual substrate, wherein the relaxed Ge channel layer is disposed above the virtual substrate. In a further aspect of the invention, a relaxed Ge channel MOSFET is provided. The method includes providing a relaxed virtual substrate with a Ge composition of approximately 100% and a relaxed Ge channel formed on the virtual substrate.Type: GrantFiled: October 23, 2007Date of Patent: May 7, 2013Assignee: Massachusetts Institute of TechnologyInventors: Minjoo L. Lee, Christopher W. Leitz, Eugene A. Fitzgerald
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Patent number: 8426845Abstract: An embodiment of the present invention improves the fabrication and operational characteristics of a type-II superlattice material. Layers of indium arsenide and gallium antimonide comprise the bulk of the superlattice structure. One or more layers of indium antimonide are added to unit cells of the superlattice to provide a further degree of freedom in the design for adjusting the effective bandgap energy of the superlattice. One or more layers of gallium arsenide are added to unit cells of the superlattice to counterbalance the crystal lattice strain forces introduced by the aforementioned indium antimonide layers.Type: GrantFiled: May 6, 2011Date of Patent: April 23, 2013Assignee: SVT Associates, Inc.Inventors: Yiqiao Chen, Peter Chow
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Patent number: 8415655Abstract: The present disclosure relates to a semiconductor light-emitting device which includes: a light-emitting layer composed of an active layer and of barrier layers formed as superlattice layers and disposed on and under the active layer to relieve stresses applied to the active layer and reduce the sum of electric fields generated in the active layer by the spontaneous polarization and the piezoelectric effect; an N-type contact layer injecting electrons into the light-emitting layer; and a P-type contact layer disposed opposite to the N-type contact layer with respect to the light-emitting layer and injecting holes into the light-emitting layer, wherein the active layer contains InGaN, and the barrier layers are formed by alternately stacking of an AlGaN thin film and an InGaN thin film.Type: GrantFiled: August 12, 2009Date of Patent: April 9, 2013Assignee: Wooree E&L Co., Ltd.Inventors: Jung Tae Jang, Bun Hei Koo, Do Yeol Ahn, Seoung Hwan Park
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Patent number: 8415761Abstract: Exemplary embodiments of the invention include a thermoelectric material having an aligned polarization field along a central axis of the material. Along the axis are a first atomic plane and a second atomic plane of substantially similar area. The planes define a first volume and form a single anisotropic crystal. The first volume has a first outer surface and a second outer surface opposite the first outer surface, with the outer surfaces defining the central axis passing through a bulk. The bulk polarization field is formed from a first electrical sheet charge and a second opposing electrical sheet charge, one on each atomic plane. The opposing sheet charges define a bulk polarization field aligned with the central axis, and the bulk polarization field causes asymmetric thermal and electrical conductivity through the first volume along the central axis.Type: GrantFiled: October 30, 2009Date of Patent: April 9, 2013Assignee: Carrier CorporationInventor: Joseph V. Mantese
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Patent number: 8405065Abstract: An LED semiconductor body includes a semiconductor layer sequence which comprises a quantum structure which is intended to produce radiation and comprises at least one quantum layer and at least one barrier layer, wherein the quantum layer and the barrier layer are strained with mutually opposite mathematical signs.Type: GrantFiled: July 27, 2007Date of Patent: March 26, 2013Assignee: OSRAM Opto Semiconductors GmbHInventors: Günther Grönninger, Christian Jung, Peter Heidborn, Alexander Behres
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Publication number: 20130043458Abstract: An embodiment of the present invention improves the fabrication and operational characteristics of a type-II superlattice material. Layers of indium arsenide and gallium antimonide comprise the bulk of the superlattice structure. One or more layers of indium antimonide are added to unit cells of the superlattice to provide a further degree of freedom in the design for adjusting the effective bandgap energy of the superlattice. One or more layers of gallium arsenide antimonide are added to unit cells of the superlattice to counterbalance the crystal lattice strain forces introduced by the aforementioned indium antimonide layers.Type: ApplicationFiled: August 17, 2012Publication date: February 21, 2013Applicant: SVT Associates, Inc.Inventors: Yiqiao Chen, Peter Chow
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Publication number: 20130032781Abstract: Provided is a crack-free epitaxial substrate with reduced warping, in which a silicon substrate is used as a base substrate. The epitaxial substrate includes a (111) single crystal Si substrate, a superlattice layer group in which a plurality of superlattice layers are laminated, and a crystal layer. The superlattice layer is formed of a first unit layer and a second unit layer made of group-III nitrides having different compositions being alternately and repeatedly laminated. The crystal layer is made of a group-III nitride and formed above the base substrate so as to be positioned at an upper side of the superlattice layer group relative to the base substrate. The superlattice layer group has a compressive strain contained therein. In the superlattice layer group, the more distant the superlattice layer is from the base substrate, the greater the compressive strain becomes.Type: ApplicationFiled: August 9, 2012Publication date: February 7, 2013Applicant: NGK Insulators, Ltd.Inventors: Makoto MIYOSHI, Shigeaki Sumiya, Mikiya Ichimura, Tomohiko Sugiyama, Mitsuhiro Tanaka
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Patent number: 8362503Abstract: A semiconductor structure includes a substrate, a nucleation layer on the substrate, a compositionally graded layer on the nucleation layer, and a layer of a nitride semiconductor material on the compositionally graded layer. The layer of nitride semiconductor material includes a plurality of substantially relaxed nitride interlayers spaced apart within the layer of nitride semiconductor material. The substantially relaxed nitride interlayers include aluminum and gallium and are conductively doped with an n-type dopant, and the layer of nitride semiconductor material including the plurality of nitride interlayers has a total thickness of at least about 2.0 ?m.Type: GrantFiled: March 9, 2007Date of Patent: January 29, 2013Assignee: Cree, Inc.Inventors: Adam William Saxler, Albert Augustus Burk, Jr.
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Patent number: 8344354Abstract: A spin-polarized electron generating device includes a substrate, a buffer layer, a strained superlattice layer formed on the buffer layer, and an intermediate layer formed of a crystal having a lattice constant greater than a lattice constant of a crystal of the buffer layer, the intermediate layer intervening between the substrate and the buffer layer. The buffer layer includes cracks formed in a direction perpendicular to the substrate by tensile strain.Type: GrantFiled: March 24, 2009Date of Patent: January 1, 2013Assignee: National University Corporation Nagoya UniversityInventors: Toru Ujihara, Xiuguang Jin, Yoshikazu Takeda, Tsutomu Nakanishi, Naoto Yamamoto, Takashi Saka, Toshihiro Kato
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Patent number: 8343872Abstract: The present disclosure provides a method of fabricating that includes providing a semiconductor substrate; forming a gate structure on the substrate; performing an implantation process to form a doped region in the substrate; forming spacers on sidewalls of the gate structure; performing an first etching to form a recess in the substrate, where the first etching removes a portion of the doped region; performing a second etching to expand the recess in the substrate, where the second etching includes an etchant and a catalyst that enhances an etching rate at a remaining portion of the doped region; and filling the recess with a semiconductor material.Type: GrantFiled: November 6, 2009Date of Patent: January 1, 2013Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.Inventors: Hsueh-Chang Sung, Hsien-Hsin Lin, Kuan-Yu Chen, Chien-Chang Su, Tsz-Mei Kwok, Yi-Fang Pai
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Patent number: 8331142Abstract: An embodiment of the invention relates to a memory comprising a strained double-heterostructure having an inner semiconductor layer which is sandwiched between two outer semiconductor layers, wherein the lattice constant of the inner semiconductor layer differs from the lattice constants of the outer semiconductor layers, the resulting lattice strain in the double-heterostructure inducing the formation of at least one quantum dot inside the inner semiconductor layer, said at least one quantum dot being capable of storing charge carriers therein, and wherein, due to the lattice strain, the at least one quantum dot has an emission barrier of 1.15 eV or higher, and provides an energy state density of at least three energy states per 1000 nm3, all said at least three energy states being located in an energy band of 50 meV or less.Type: GrantFiled: December 16, 2010Date of Patent: December 11, 2012Assignee: Technische Universitat BerlinInventors: Dieter Bimberg, Martin Geller, Andreas Marent, Tobias Nowozin
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Patent number: 8298897Abstract: A field effect transistor includes a partial SiGe channel, i.e., a channel including a SiGe channel portion, located underneath a gate electrode and a Si channel portion located underneath an edge of the gate electrode near the drain region. The SiGe channel portion can be located directly underneath a gate dielectric, or can be located underneath a Si channel layer located directly underneath a gate dielectric. The Si channel portion is located at the same depth as the SiGe channel portion, and contacts the drain region of the transistor. By providing a Si channel portion near the drain region, the GIDL current of the transistor is maintained at a level on par with the GIDL current of a transistor having a silicon channel only during an off state.Type: GrantFiled: March 23, 2012Date of Patent: October 30, 2012Assignees: International Business Machines Corporation, Globalfoundries Inc.Inventors: Xiangdong Chen, Jie Deng, Weipeng Li, Deleep R. Nair, Jae-Eun Park, Daniel Tekleab, Xiaobin Yuan, Nam Sung Kim
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Patent number: 8293566Abstract: An infrared focal plane array (FPA) is disclosed which utilizes a strained-layer superlattice (SLS) formed of alternating layers of InAs and InxGa1-xSb with 0?x?0.5 epitaxially grown on a GaSb substrate. The FPA avoids the use of a mesa structure to isolate each photodetector element and instead uses impurity-doped regions formed in or about each photodetector for electrical isolation. This results in a substantially-planar structure in which the SLS is unbroken across the entire width of a 2-D array of the photodetector elements which are capped with an epitaxially-grown passivation layer to reduce or eliminate surface recombination. The FPA has applications for use in the wavelength range of 3-25 ?m.Type: GrantFiled: June 15, 2010Date of Patent: October 23, 2012Assignee: Sandia CorporationInventors: Jin K. Kim, Malcolm S. Carroll, Aaron Gin, Phillip F. Marsh, Erik W. Young, Michael J. Cich
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Patent number: 8293609Abstract: Semiconductor transistor devices and related fabrication methods are provided. An exemplary transistor device includes a layer of semiconductor material having a channel region defined therein and a gate structure overlying the channel region. Recesses are formed in the layer of semiconductor material adjacent to the channel region, such that the recesses extend asymmetrically toward the channel region. The transistor device also includes stress-inducing semiconductor material formed in the recesses. The asymmetric profile of the stress-inducing semiconductor material enhances carrier mobility in a manner that does not exacerbate the short channel effect.Type: GrantFiled: January 20, 2012Date of Patent: October 23, 2012Assignee: GLOBALFOUNDRIES, Inc.Inventors: Rohit Pal, Frank Bin Yang, Michael J. Hargrove
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Patent number: 8288757Abstract: A recess along a sidewall is formed in a pMOS region and an nMOS region. An SiC layer of which thickness is thicker than a depth of the recess is formed in the recess. A sidewall covering a part of the SiC layer is formed at both lateral sides of a gate electrode in the pMOS region. A recess is formed by selectively removing the SiC layer in the pMOS region. A side surface of the recess at the gate insulating film side is inclined so that the upper region of the side surface, the closer to the gate insulating film in a lateral direction at a region lower than the surface of the silicon substrate. An SiGe layer is formed in the recess in the pMOS region.Type: GrantFiled: September 29, 2010Date of Patent: October 16, 2012Assignee: Fujitsu Semiconductor LimitedInventors: Hiroyuki Ohta, Yosuke Shimamune
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Patent number: 8288756Abstract: The present invention provides a method of forming a transistor. The method includes forming a first layer of a first semiconductor material above an insulation layer. The first semiconductor material is selected to provide high mobility to a first carrier type. The method also includes forming a second layer of a second semiconductor material above the first layer of semiconductor material. The second semiconductor material is selected to provide high mobility to a second carrier type opposite the first carrier type. The method further includes forming a first masking layer adjacent the second layer and etching the second layer through the first masking layer to form at least one feature in the second layer. Each feature in the second layer forms an inverted-T shape with a portion of the second layer.Type: GrantFiled: November 30, 2007Date of Patent: October 16, 2012Assignee: Advanced Micro Devices, Inc.Inventors: Hemant Adhikari, Rusty Harris
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Patent number: 8283653Abstract: Techniques are disclosed for forming a non-planar germanium quantum well structure. In particular, the quantum well structure can be implemented with group IV or III-V semiconductor materials and includes a germanium fin structure. In one example case, a non-planar quantum well device is provided, which includes a quantum well structure having a substrate (e.g. SiGe or GaAs buffer on silicon), a IV or III-V material barrier layer (e.g., SiGe or GaAs or AlGaAs), a doping layer (e.g., delta/modulation doped), and an undoped germanium quantum well layer. An undoped germanium fin structure is formed in the quantum well structure, and a top barrier layer deposited over the fin structure. A gate metal can be deposited across the fin structure. Drain/source regions can be formed at respective ends of the fin structure.Type: GrantFiled: December 23, 2009Date of Patent: October 9, 2012Assignee: Intel CorporationInventors: Ravi Pillarisetty, Jack T. Kavalieros, Willy Rachmady, Uday Shah, Benjamin Chu-Kung, Marko Radosavljevic, Niloy Mukherjee, Gilbert Dewey, Been Y. Jin, Robert S. Chau
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Patent number: 8274071Abstract: A semiconductor structure includes a semiconductor substrate having a first lattice constant; a gate dielectric on the semiconductor substrate; a gate electrode on the semiconductor substrate; and a stressor having at least a portion in the semiconductor substrate and adjacent the gate electrode. The stressor has a tilted sidewall on a side adjacent the gate electrode. The stressor includes a first stressor layer having a second lattice constant substantially different from the first lattice constant; and a second stressor layer on the first stressor layer, wherein the second stressor has a third lattice constant substantially different from the first and the second lattice constants.Type: GrantFiled: January 6, 2011Date of Patent: September 25, 2012Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.Inventors: Ming-Hua Yu, Mong-Song Liang, Tze-Liang Lee, Jr.-Hung Li
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Patent number: 8253166Abstract: Systems and methods for improving the temperature performance of AlInGaP based light emitters. Nitrogen is added to the quantum wells in small quantities. Nitrogen is added in a range of about 0.5 percent to 2 percent. The addition of nitrogen increases the conduction band offset and increases the separation of the indirect conduction band. To keep the emission wavelength in a particular range, the concentration of In in the quantum wells may be decreased or the concentration of Al in the quantum wells may be increased. Because the depth of the quantum wells in the valence band is more than is required although the addition of nitrogen reduces the depth of the quantum wells in the valence band. The net result is an increase in the conduction band offset and an increase in the separation of the indirect conduction band.Type: GrantFiled: September 14, 2004Date of Patent: August 28, 2012Assignee: Finisar CorporationInventor: Ralph Herbert Johnson
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Patent number: 8242484Abstract: The invention is a vertical geometry light emitting diode capable of emitting light in the electromagnetic spectrum having a substrate, a lift-off layer, a strain relieved superlattice layer, a first doped layer, a multilayer quantum wells comprising alternating layers quantum wells and barrier layers, a second doped layer, a third doped layer and a metallic contact that is in a vertical geometry orientation. The different layers consist of a compound with the formula AlxlnyGa(1-x-y)N, wherein x is more than 0 and less than or equal to 1, y is from 0 to 1 and x+y is greater than 0 and less than or equal to 1. The barrier layer on each surface of the quantum well has a band gap larger than a quantum well bandgap. The first and second doped layers have different conductivities. The contact layer has a different conductivity than the third doped layer.Type: GrantFiled: October 17, 2007Date of Patent: August 14, 2012Assignee: Nitek, Inc.Inventor: Asif Khan
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Patent number: 8237150Abstract: A p-type semiconductor nanowire transistor is formed on the first semiconductor nanowire and an n-type semiconductor nanowire transistor is formed on the second semiconductor nanowire. The first and second semiconductor nanowires have a rectangular cross-sectional area with different width-to-height ratios. The type of semiconductor nanowires for each semiconductor nanowire transistor is selected such that top and bottom surfaces provide a greater on-current per unit width than sidewall surfaces in a semiconductor nanowire having a greater width-to-height ratio, while sidewall surfaces provide a greater on-current per unit width than top and bottom surfaces in the other semiconductor nanowire having a lesser width-to-height ratio. Different types of stress-generating material layers may be formed on the first and second semiconductor nanowire transistors to provide opposite types of stress, which may be employed to enhance the on-current of the first and second semiconductor nanowire transistors.Type: GrantFiled: April 3, 2009Date of Patent: August 7, 2012Assignee: International Business Machines CorporationInventors: Dureseti Chidambarrao, Xiao H. Liu, Lidija Sekaric
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Patent number: 8237197Abstract: A field effect transistor includes a partial SiGe channel, i.e., a channel including a SiGe channel portion, located underneath a gate electrode and a Si channel portion located underneath an edge of the gate electrode near the drain region. The SiGe channel portion can be located directly underneath a gate dielectric, or can be located underneath a Si channel layer located directly underneath a gate dielectric. The Si channel portion is located at the same depth as the SiGe channel portion, and contacts the drain region of the transistor. By providing a Si channel portion near the drain region, the GIDL current of the transistor is maintained at a level on par with the GIDL current of a transistor having a silicon channel only during an off state.Type: GrantFiled: July 7, 2010Date of Patent: August 7, 2012Assignees: International Business Machines Corporation, Globalfoundries Inc.Inventors: Xiangdong Chen, Jie Deng, Weipeng Li, Deleep R. Nair, Jae-Eun Park, Daniel Tekleab, Xiaobin Yuan, Nam Sung Kim
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Patent number: 8232165Abstract: A semiconductor structure includes an n-channel field effect transistor (NFET) nanowire, the NFET nanowire comprising a film wrapping around a core of the NFET nanowire, the film wrapping configured to provide tensile stress in the NFET nanowire. A method of making a semiconductor structure includes growing a film wrapping around a core of an n-channel field effect transistor (NFET) nanowire of the semiconductor structure, the film wrapping being configured to provide tensile stress in the NFET nanowire.Type: GrantFiled: July 15, 2011Date of Patent: July 31, 2012Assignee: International Business Machines CorporationInventors: Dureseti Chidambarrao, Lidija Sekaric
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Patent number: 8227791Abstract: A strain balanced active-region design is disclosed for optoelectronic devices such as light-emitting diodes (LEDs) and laser diodes (LDs) for better device performance. Lying below the active-region, a lattice-constant tailored strain-balancing layer provides lattice template for the active-region, enabling balanced strain within the active-region for the purposes of 1) growing thick, multiple-layer active-region with reduced defects, or 2) engineering polarization fields within the active-region for enhanced performance. The strain-balancing layer in general enlarges active-region design and growth windows. In some embodiments of the present invention, the strain-balancing layer is made of quaternary InxAlyGa1-x-yN (0?x?1, 0?y?1, x+y?1), whose lattice-constant is tailored to exert opposite strains in adjoining layers within the active-region. A relaxation-enhancement layer can be provided beneath the strain-balancing layer for enhancing the relaxation of the strain-balancing layer.Type: GrantFiled: January 25, 2010Date of Patent: July 24, 2012Assignee: Invenlux LimitedInventor: Chunhui Yan