JP2006019727A5 - - Google Patents

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JP2006019727A5
JP2006019727A5 JP2005183624A JP2005183624A JP2006019727A5 JP 2006019727 A5 JP2006019727 A5 JP 2006019727A5 JP 2005183624 A JP2005183624 A JP 2005183624A JP 2005183624 A JP2005183624 A JP 2005183624A JP 2006019727 A5 JP2006019727 A5 JP 2006019727A5
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layer
soi
forming
dopant
insulator
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JP2005183624A
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JP2006019727A (ja
JP5043314B2 (ja
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JP2005183624A 2004-06-29 2005-06-23 勾配付き組み込みシリコン−ゲルマニウムのソース−ドレイン及び／又は延長部をもつ、歪みｐ型ｍｏｓｆｅｔを製造する方法 Expired - Fee Related JP5043314B2 (ja)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US10/710244 2004-06-29
US10/710,244 US7288443B2 (en) 2004-06-29 2004-06-29 Structures and methods for manufacturing p-type MOSFET with graded embedded silicon-germanium source-drain and/or extension

Publications (3)

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JP2006019727A JP2006019727A (ja) 2006-01-19
JP2006019727A5 true JP2006019727A5 (enExample) 2008-06-19
JP5043314B2 JP5043314B2 (ja) 2012-10-10

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JP2005183624A Expired - Fee Related JP5043314B2 (ja) 2004-06-29 2005-06-23 勾配付き組み込みシリコン−ゲルマニウムのソース−ドレイン及び／又は延長部をもつ、歪みｐ型ｍｏｓｆｅｔを製造する方法

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US (1) US7288443B2 (enExample)
JP (1) JP5043314B2 (enExample)
CN (1) CN100444336C (enExample)
TW (1) TW200625460A (enExample)

Families Citing this family (39)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7018901B1 (en) * 2004-09-29 2006-03-28 Freescale Semiconductor, Inc. Method for forming a semiconductor device having a strained channel and a heterojunction source/drain
US20060151808A1 (en) * 2005-01-12 2006-07-13 Chien-Hao Chen MOSFET device with localized stressor
DE102005013982A1 (de) * 2005-03-26 2006-10-05 Atmel Germany Gmbh Verfahren zur Herstellung eines Bipolartransistors und nach einem derartigen Verfahren hergestellter Bipolartransistor
US7439165B2 (en) * 2005-04-06 2008-10-21 Agency For Sceince, Technology And Reasearch Method of fabricating tensile strained layers and compressive strain layers for a CMOS device
US7446350B2 (en) * 2005-05-10 2008-11-04 International Business Machine Corporation Embedded silicon germanium using a double buried oxide silicon-on-insulator wafer
KR100675895B1 (ko) * 2005-06-29 2007-02-02 주식회사 하이닉스반도체 반도체소자의 금속배선구조 및 그 제조방법
EP1833094B1 (en) * 2006-03-06 2011-02-02 STMicroelectronics (Crolles 2) SAS Formation of shallow SiGe conduction channel
CN100466255C (zh) * 2006-04-18 2009-03-04 联华电子股份有限公司 半导体结构及其制作方法
US8211761B2 (en) * 2006-08-16 2012-07-03 Globalfoundries Singapore Pte. Ltd. Semiconductor system using germanium condensation
KR100773359B1 (ko) * 2006-11-20 2007-11-05 삼성전자주식회사 높은 이동도를 갖는 트랜지스터들의 제조방법 및 그에 의해제조된 트랜지스터들
US7696000B2 (en) * 2006-12-01 2010-04-13 International Business Machines Corporation Low defect Si:C layer with retrograde carbon profile
CN101295641B (zh) * 2007-04-24 2010-09-29 中芯国际集成电路制造(上海)有限公司 栅极制造方法
KR100844933B1 (ko) * 2007-06-26 2008-07-09 주식회사 하이닉스반도체 반도체 소자의 트랜지스터 및 그 제조 방법
US7709331B2 (en) * 2007-09-07 2010-05-04 Freescale Semiconductor, Inc. Dual gate oxide device integration
US7704844B2 (en) * 2007-10-04 2010-04-27 International Business Machines Corporation High performance MOSFET
US7964910B2 (en) * 2007-10-17 2011-06-21 International Business Machines Corporation Planar field effect transistor structure having an angled crystallographic etch-defined source/drain recess and a method of forming the transistor structure
CN101458337B (zh) * 2007-12-12 2010-12-08 中国科学院微电子研究所 基于绝缘体上硅的双探头pmos辐射剂量计
CN101937091B (zh) * 2007-12-12 2012-07-25 中国科学院微电子研究所 一种可调整量程的堆叠测量电路
US20090242989A1 (en) * 2008-03-25 2009-10-01 Chan Kevin K Complementary metal-oxide-semiconductor device with embedded stressor
US7955909B2 (en) * 2008-03-28 2011-06-07 International Business Machines Corporation Strained ultra-thin SOI transistor formed by replacement gate
FR2936095B1 (fr) * 2008-09-18 2011-04-01 Commissariat Energie Atomique Procede de fabrication d'un dispositif microelectronique dote de zones semi-conductrices sur isolant a gradient horizontal de concentration en ge.
US8623728B2 (en) * 2009-07-28 2014-01-07 Taiwan Semiconductor Manufacturing Company, Ltd. Method for forming high germanium concentration SiGe stressor
KR101297397B1 (ko) * 2009-09-09 2013-08-19 각고우호우진 가나가와 다이가쿠 반도체 소자구조의 형성 방법, 및 반도체 소자
TWI416727B (zh) * 2009-12-04 2013-11-21 Inotera Memories Inc Ｐ型金屬氧化層半導體場效電晶體及其製造方法
CN102130054B (zh) * 2010-01-20 2013-05-01 中芯国际集成电路制造(上海)有限公司 改善半导体器件的截止漏电流发散的方法
CN102339852B (zh) 2010-07-27 2013-03-27 中国科学院微电子研究所 半导体器件及其制造方法
CN102569383A (zh) * 2010-12-14 2012-07-11 中国科学院微电子研究所 一种mos管及其制造方法
US20120161105A1 (en) * 2010-12-22 2012-06-28 Willy Rachmady Uniaxially strained quantum well device and method of making same
DE102010064290B3 (de) * 2010-12-28 2012-04-19 GLOBALFOUNDRIES Dresden Module One Ltd. Liability Company & Co. KG Verformungserhöhung in Transistoren mit einem eingebetteten verformungsinduzierenden Halbleitermaterial durch Kondensation der legierungsbildenden Substanz
CN102800594B (zh) * 2011-05-26 2015-01-28 中芯国际集成电路制造(上海)有限公司 Pmos管的制作方法
CN102931082B (zh) * 2011-08-10 2015-04-22 中芯国际集成电路制造(北京)有限公司 半导体器件及其制造方法
US8735303B2 (en) * 2011-11-02 2014-05-27 Globalfoundries Inc. Methods of forming PEET devices with different structures and performance characteristics
US8957476B2 (en) * 2012-12-20 2015-02-17 Intel Corporation Conversion of thin transistor elements from silicon to silicon germanium
US9876110B2 (en) * 2014-01-31 2018-01-23 Stmicroelectronics, Inc. High dose implantation for ultrathin semiconductor-on-insulator substrates
CN105679645A (zh) * 2014-11-17 2016-06-15 上海华力微电子有限公司 嵌入式锗硅外延位错缺陷的改善方法
US10043893B1 (en) * 2017-08-03 2018-08-07 Globalfoundries Inc. Post gate silicon germanium channel condensation and method for producing the same
US11041569B2 (en) * 2019-05-03 2021-06-22 Tapcoenpro, Llc Systems and methods for floating seat plate
CN112635325A (zh) * 2020-12-07 2021-04-09 广东省大湾区集成电路与系统应用研究院 一种绝缘体上应变硅/锗晶体管及其制备方法
CN113410309A (zh) * 2021-06-23 2021-09-17 电子科技大学 一种低比导通电阻的分立栅mosfet器件及其制造方法

Family Cites Families (97)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3602841A (en) 1970-06-18 1971-08-31 Ibm High frequency bulk semiconductor amplifiers and oscillators
US4853076A (en) 1983-12-29 1989-08-01 Massachusetts Institute Of Technology Semiconductor thin films
US4665415A (en) 1985-04-24 1987-05-12 International Business Machines Corporation Semiconductor device with hole conduction via strained lattice
EP0219641B1 (de) 1985-09-13 1991-01-09 Siemens Aktiengesellschaft Integrierte Bipolar- und komplementäre MOS-Transistoren auf einem gemeinsamen Substrat enthaltende Schaltung und Verfahren zu ihrer Herstellung
JPS6476755A (en) 1987-09-18 1989-03-22 Hitachi Ltd Semiconductor device
US4958213A (en) 1987-12-07 1990-09-18 Texas Instruments Incorporated Method for forming a transistor base region under thick oxide
US5354695A (en) 1992-04-08 1994-10-11 Leedy Glenn J Membrane dielectric isolation IC fabrication
US5459346A (en) 1988-06-28 1995-10-17 Ricoh Co., Ltd. Semiconductor substrate with electrical contact in groove
US5006913A (en) 1988-11-05 1991-04-09 Mitsubishi Denki Kabushiki Kaisha Stacked type semiconductor device
US5108843A (en) 1988-11-30 1992-04-28 Ricoh Company, Ltd. Thin film semiconductor and process for producing the same
US4952524A (en) 1989-05-05 1990-08-28 At&T Bell Laboratories Semiconductor device manufacture including trench formation
US5310446A (en) 1990-01-10 1994-05-10 Ricoh Company, Ltd. Method for producing semiconductor film
US5060030A (en) 1990-07-18 1991-10-22 Raytheon Company Pseudomorphic HEMT having strained compensation layer
US5081513A (en) 1991-02-28 1992-01-14 Xerox Corporation Electronic device with recovery layer proximate to active layer
US5371399A (en) 1991-06-14 1994-12-06 International Business Machines Corporation Compound semiconductor having metallic inclusions and devices fabricated therefrom
US5134085A (en) 1991-11-21 1992-07-28 Micron Technology, Inc. Reduced-mask, split-polysilicon CMOS process, incorporating stacked-capacitor cells, for fabricating multi-megabit dynamic random access memories
US5391510A (en) 1992-02-28 1995-02-21 International Business Machines Corporation Formation of self-aligned metal gate FETs using a benignant removable gate material during high temperature steps
US6008126A (en) 1992-04-08 1999-12-28 Elm Technology Corporation Membrane dielectric isolation IC fabrication
US5561302A (en) 1994-09-26 1996-10-01 Motorola, Inc. Enhanced mobility MOSFET device and method
US5670798A (en) 1995-03-29 1997-09-23 North Carolina State University Integrated heterostructures of Group III-V nitride semiconductor materials including epitaxial ohmic contact non-nitride buffer layer and methods of fabricating same
US5679965A (en) 1995-03-29 1997-10-21 North Carolina State University Integrated heterostructures of Group III-V nitride semiconductor materials including epitaxial ohmic contact, non-nitride buffer layer and methods of fabricating same
US5557122A (en) 1995-05-12 1996-09-17 Alliance Semiconductors Corporation Semiconductor electrode having improved grain structure and oxide growth properties
JP3450547B2 (ja) * 1995-09-14 2003-09-29 株式会社東芝 半導体装置およびその製造方法
KR100213196B1 (ko) 1996-03-15 1999-08-02 윤종용 트렌치 소자분리
US6403975B1 (en) 1996-04-09 2002-06-11 Max-Planck Gesellschaft Zur Forderung Der Wissenschafteneev Semiconductor components, in particular photodetectors, light emitting diodes, optical modulators and waveguides with multilayer structures grown on silicon substrates
US5880040A (en) 1996-04-15 1999-03-09 Macronix International Co., Ltd. Gate dielectric based on oxynitride grown in N2 O and annealed in NO
JP3383154B2 (ja) * 1996-06-20 2003-03-04 株式会社東芝 半導体装置
EP0865686B1 (en) * 1996-09-06 2004-12-08 Koninklijke Philips Electronics N.V. A zero-if receiver
US5861651A (en) 1997-02-28 1999-01-19 Lucent Technologies Inc. Field effect devices and capacitors with improved thin film dielectrics and method for making same
US5940736A (en) 1997-03-11 1999-08-17 Lucent Technologies Inc. Method for forming a high quality ultrathin gate oxide layer
US6309975B1 (en) 1997-03-14 2001-10-30 Micron Technology, Inc. Methods of making implanted structures
US6025280A (en) 1997-04-28 2000-02-15 Lucent Technologies Inc. Use of SiD4 for deposition of ultra thin and controllable oxides
US5960297A (en) 1997-07-02 1999-09-28 Kabushiki Kaisha Toshiba Shallow trench isolation structure and method of forming the same
JPH1197673A (ja) * 1997-09-17 1999-04-09 Toshiba Corp 半導体装置
JP3139426B2 (ja) 1997-10-15 2001-02-26 日本電気株式会社 半導体装置
US6066545A (en) 1997-12-09 2000-05-23 Texas Instruments Incorporated Birdsbeak encroachment using combination of wet and dry etch for isolation nitride
US6274421B1 (en) 1998-01-09 2001-08-14 Sharp Laboratories Of America, Inc. Method of making metal gate sub-micron MOS transistor
KR100275908B1 (ko) 1998-03-02 2000-12-15 윤종용 집적 회로에 트렌치 아이솔레이션을 형성하는방법
US6165383A (en) 1998-04-10 2000-12-26 Organic Display Technology Useful precursors for organic electroluminescent materials and devices made from such materials
US6361885B1 (en) 1998-04-10 2002-03-26 Organic Display Technology Organic electroluminescent materials and device made from such materials
US5989978A (en) 1998-07-16 1999-11-23 Chartered Semiconductor Manufacturing, Ltd. Shallow trench isolation of MOSFETS with reduced corner parasitic currents
JP4592837B2 (ja) 1998-07-31 2010-12-08 ルネサスエレクトロニクス株式会社 半導体装置の製造方法
US6319794B1 (en) 1998-10-14 2001-11-20 International Business Machines Corporation Structure and method for producing low leakage isolation devices
US6235598B1 (en) 1998-11-13 2001-05-22 Intel Corporation Method of using thick first spacers to improve salicide resistance on polysilicon gates
US6117722A (en) 1999-02-18 2000-09-12 Taiwan Semiconductor Manufacturing Company SRAM layout for relaxing mechanical stress in shallow trench isolation technology and method of manufacture thereof
US6255169B1 (en) 1999-02-22 2001-07-03 Advanced Micro Devices, Inc. Process for fabricating a high-endurance non-volatile memory device
US6284626B1 (en) 1999-04-06 2001-09-04 Vantis Corporation Angled nitrogen ion implantation for minimizing mechanical stress on side walls of an isolation trench
US6362082B1 (en) 1999-06-28 2002-03-26 Intel Corporation Methodology for control of short channel effects in MOS transistors
US6281532B1 (en) 1999-06-28 2001-08-28 Intel Corporation Technique to obtain increased channel mobilities in NMOS transistors by gate electrode engineering
US6656822B2 (en) 1999-06-28 2003-12-02 Intel Corporation Method for reduced capacitance interconnect system using gaseous implants into the ILD
US6228694B1 (en) 1999-06-28 2001-05-08 Intel Corporation Method of increasing the mobility of MOS transistors by use of localized stress regions
KR100332108B1 (ko) 1999-06-29 2002-04-10 박종섭 반도체 소자의 트랜지스터 및 그 제조 방법
TW426940B (en) 1999-07-30 2001-03-21 United Microelectronics Corp Manufacturing method of MOS field effect transistor
US6483171B1 (en) 1999-08-13 2002-11-19 Micron Technology, Inc. Vertical sub-micron CMOS transistors on (110), (111), (311), (511), and higher order surfaces of bulk, SOI and thin film structures and method of forming same
US6284623B1 (en) 1999-10-25 2001-09-04 Peng-Fei Zhang Method of fabricating semiconductor devices using shallow trench isolation with reduced narrow channel effect
US6476462B2 (en) 1999-12-28 2002-11-05 Texas Instruments Incorporated MOS-type semiconductor device and method for making same
US6221735B1 (en) 2000-02-15 2001-04-24 Philips Semiconductors, Inc. Method for eliminating stress induced dislocations in CMOS devices
US6531369B1 (en) 2000-03-01 2003-03-11 Applied Micro Circuits Corporation Heterojunction bipolar transistor (HBT) fabrication using a selectively deposited silicon germanium (SiGe)
US6368931B1 (en) 2000-03-27 2002-04-09 Intel Corporation Thin tensile layers in shallow trench isolation and method of making same
US6493497B1 (en) 2000-09-26 2002-12-10 Motorola, Inc. Electro-optic structure and process for fabricating same
US6501121B1 (en) 2000-11-15 2002-12-31 Motorola, Inc. Semiconductor structure
US7312485B2 (en) 2000-11-29 2007-12-25 Intel Corporation CMOS fabrication process utilizing special transistor orientation
US6563152B2 (en) 2000-12-29 2003-05-13 Intel Corporation Technique to obtain high mobility channels in MOS transistors by forming a strain layer on an underside of a channel
US20020086497A1 (en) 2000-12-30 2002-07-04 Kwok Siang Ping Beaker shape trench with nitride pull-back for STI
US6265317B1 (en) 2001-01-09 2001-07-24 Taiwan Semiconductor Manufacturing Company Top corner rounding for shallow trench isolation
US6403486B1 (en) 2001-04-30 2002-06-11 Taiwan Semiconductor Manufacturing Company Method for forming a shallow trench isolation
US6531740B2 (en) 2001-07-17 2003-03-11 Motorola, Inc. Integrated impedance matching and stability network
US6498358B1 (en) 2001-07-20 2002-12-24 Motorola, Inc. Structure and method for fabricating an electro-optic system having an electrochromic diffraction grating
US6908810B2 (en) 2001-08-08 2005-06-21 Taiwan Semiconductor Manufacturing Co., Ltd. Method of preventing threshold voltage of MOS transistor from being decreased by shallow trench isolation formation
JP2003060076A (ja) 2001-08-21 2003-02-28 Nec Corp 半導体装置及びその製造方法
EP1428262A2 (en) 2001-09-21 2004-06-16 Amberwave Systems Corporation Semiconductor structures employing strained material layers with defined impurity gradients and methods for fabricating same
US20030057184A1 (en) 2001-09-22 2003-03-27 Shiuh-Sheng Yu Method for pull back SiN to increase rounding effect in a shallow trench isolation process
US6656798B2 (en) 2001-09-28 2003-12-02 Infineon Technologies, Ag Gate processing method with reduced gate oxide corner and edge thinning
US6621131B2 (en) * 2001-11-01 2003-09-16 Intel Corporation Semiconductor transistor having a stressed channel
US6635506B2 (en) 2001-11-07 2003-10-21 International Business Machines Corporation Method of fabricating micro-electromechanical switches on CMOS compatible substrates
US6461936B1 (en) 2002-01-04 2002-10-08 Infineon Technologies Ag Double pullback method of filling an isolation trench
JP4173672B2 (ja) * 2002-03-19 2008-10-29 株式会社ルネサステクノロジ 半導体装置及びその製造方法
US6621392B1 (en) 2002-04-25 2003-09-16 International Business Machines Corporation Micro electromechanical switch having self-aligned spacers
JP2003318198A (ja) * 2002-04-25 2003-11-07 Sanyo Electric Co Ltd 半導体装置の製造方法
US7388259B2 (en) 2002-11-25 2008-06-17 International Business Machines Corporation Strained finFET CMOS device structures
US6717216B1 (en) 2002-12-12 2004-04-06 International Business Machines Corporation SOI based field effect transistor having a compressive film in undercut area under the channel and a method of making the device
US6825529B2 (en) 2002-12-12 2004-11-30 International Business Machines Corporation Stress inducing spacers
US6974981B2 (en) 2002-12-12 2005-12-13 International Business Machines Corporation Isolation structures for imposing stress patterns
CN100437970C (zh) * 2003-03-07 2008-11-26 琥珀波系统公司 一种结构及用于形成半导体结构的方法
US6900502B2 (en) * 2003-04-03 2005-05-31 Taiwan Semiconductor Manufacturing Company, Ltd. Strained channel on insulator device
US6887798B2 (en) 2003-05-30 2005-05-03 International Business Machines Corporation STI stress modification by nitrogen plasma treatment for improving performance in small width devices
US7279746B2 (en) 2003-06-30 2007-10-09 International Business Machines Corporation High performance CMOS device structures and method of manufacture
US7119403B2 (en) 2003-10-16 2006-10-10 International Business Machines Corporation High performance strained CMOS devices
US6977194B2 (en) 2003-10-30 2005-12-20 International Business Machines Corporation Structure and method to improve channel mobility by gate electrode stress modification
US8008724B2 (en) 2003-10-30 2011-08-30 International Business Machines Corporation Structure and method to enhance both nFET and pFET performance using different kinds of stressed layers
US7015082B2 (en) 2003-11-06 2006-03-21 International Business Machines Corporation High mobility CMOS circuits
US7122849B2 (en) 2003-11-14 2006-10-17 International Business Machines Corporation Stressed semiconductor device structures having granular semiconductor material
US7247912B2 (en) 2004-01-05 2007-07-24 International Business Machines Corporation Structures and methods for making strained MOSFETs
CA2454995C (en) * 2004-01-07 2011-12-20 Martinrea International Inc. Method and apparatus for assembling and testing a fluid conduit
US7205206B2 (en) 2004-03-03 2007-04-17 International Business Machines Corporation Method of fabricating mobility enhanced CMOS devices
US7504693B2 (en) 2004-04-23 2009-03-17 International Business Machines Corporation Dislocation free stressed channels in bulk silicon and SOI CMOS devices by gate stress engineering
US7354806B2 (en) 2004-09-17 2008-04-08 International Business Machines Corporation Semiconductor device structure with active regions having different surface directions and methods

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