DE102004034103A1 - Verfahren zur Abscheidung von Silizium und Germanium enthaltenen Schichten und Schichtfolgen unter Verwendung von nicht-kontinuierlicher Injektion von flüssigen und gelösten Ausgangssubstanzen über eine Mehrkanalinjektionseinheit - Google Patents

Verfahren zur Abscheidung von Silizium und Germanium enthaltenen Schichten und Schichtfolgen unter Verwendung von nicht-kontinuierlicher Injektion von flüssigen und gelösten Ausgangssubstanzen über eine Mehrkanalinjektionseinheit Download PDF

Info

Publication number
DE102004034103A1
DE102004034103A1 DE102004034103A DE102004034103A DE102004034103A1 DE 102004034103 A1 DE102004034103 A1 DE 102004034103A1 DE 102004034103 A DE102004034103 A DE 102004034103A DE 102004034103 A DE102004034103 A DE 102004034103A DE 102004034103 A1 DE102004034103 A1 DE 102004034103A1
Authority
DE
Germany
Prior art keywords
deposition
passivating
substrate
electrically conductive
insulating
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
DE102004034103A
Other languages
English (en)
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Aixtron SE
Original Assignee
Aixtron SE
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Aixtron SE filed Critical Aixtron SE
Priority to DE102004034103A priority Critical patent/DE102004034103A1/de
Priority to EP05716765A priority patent/EP1774056B1/de
Priority to JP2007520787A priority patent/JP2008506617A/ja
Priority to US11/572,101 priority patent/US7732308B2/en
Priority to PCT/EP2005/050756 priority patent/WO2006005637A1/de
Priority to KR1020077002899A priority patent/KR20070037503A/ko
Priority to TW094107777A priority patent/TWI390073B/zh
Publication of DE102004034103A1 publication Critical patent/DE102004034103A1/de
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
    • C23C16/4411—Cooling of the reaction chamber walls
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
    • C23C16/448—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating characterised by the method used for generating reactive gas streams, e.g. by evaporation or sublimation of precursor materials
    • C23C16/4481—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating characterised by the method used for generating reactive gas streams, e.g. by evaporation or sublimation of precursor materials by evaporation using carrier gas in contact with the source material
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
    • C23C16/52—Controlling or regulating the coating process
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S438/00—Semiconductor device manufacturing: process
    • Y10S438/933—Germanium or silicon or Ge-Si on III-V

Landscapes

  • Chemical & Material Sciences (AREA)
  • General Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Chemical Vapour Deposition (AREA)
  • Formation Of Insulating Films (AREA)
  • Electrodes Of Semiconductors (AREA)

Abstract

Die Erfindung betrifft ein Verfahren zum Abscheiden mindestens einer Halbleiterschicht auf mindestens einem Substrat in einer Prozesskammer (2), wobei die Halbleiterschicht aus mehreren Komponenten besteht und die Komponenten mittels nicht kontinuierlicher Injektion eines flüssigen oder in einer Flüssigkeit gelösten Ausgangsstoffes (3) mittels je einer Injektoreinheit (5) in einer temperierten Verdampfungskammer (4) verdampft werden und dieser Dampf mittels eines Trägergases (7) der Prozesskammer zugeführt wird. Wesentlich ist, dass die den zeitlichen Verlauf des Massenflusses eines Silizium enthaltenen ersten Ausgangsstoffes und eines Germanium enthaltenen zweiten Ausgangsstoffes (3) durch die zugeordnete Injektoreinheit (5) bestimmenden Massenfluss-Parameter, wie der Injektionsdruck, die Injektionsfrequenz und das Puls/Pausenverhältnis sowie die Phasenbeziehung der Puls/Pausen zu den Pulsen/Pausen der anderen Injektoreinheit(en), individuell eingestellt oder variiert werden.
DE102004034103A 2003-09-17 2004-07-15 Verfahren zur Abscheidung von Silizium und Germanium enthaltenen Schichten und Schichtfolgen unter Verwendung von nicht-kontinuierlicher Injektion von flüssigen und gelösten Ausgangssubstanzen über eine Mehrkanalinjektionseinheit Withdrawn DE102004034103A1 (de)

Priority Applications (7)

Application Number Priority Date Filing Date Title
DE102004034103A DE102004034103A1 (de) 2003-09-17 2004-07-15 Verfahren zur Abscheidung von Silizium und Germanium enthaltenen Schichten und Schichtfolgen unter Verwendung von nicht-kontinuierlicher Injektion von flüssigen und gelösten Ausgangssubstanzen über eine Mehrkanalinjektionseinheit
EP05716765A EP1774056B1 (de) 2004-07-15 2005-02-22 Verfahren zur abscheidung von silizium und germanium enthaltenden schichten
JP2007520787A JP2008506617A (ja) 2004-07-15 2005-02-22 ＳｉとＧｅを含有する膜の堆積方法
US11/572,101 US7732308B2 (en) 2003-09-17 2005-02-22 Process for depositing layers containing silicon and germanium
PCT/EP2005/050756 WO2006005637A1 (de) 2004-07-15 2005-02-22 Verfahren zur abscheidung von silizium und germanium enthaltenden schichten
KR1020077002899A KR20070037503A (ko) 2004-07-15 2005-02-22 실리콘 및 게르마늄을 포함하는 층들의 증착 방법
TW094107777A TWI390073B (zh) 2004-07-15 2005-03-15 A method of depositing a silicon and germanium-containing thin film and a laminate by discontinuously ejecting a liquid and a dissolving material in a multi-channel ejection unit

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE10342890 2003-09-17
DE102004034103A DE102004034103A1 (de) 2003-09-17 2004-07-15 Verfahren zur Abscheidung von Silizium und Germanium enthaltenen Schichten und Schichtfolgen unter Verwendung von nicht-kontinuierlicher Injektion von flüssigen und gelösten Ausgangssubstanzen über eine Mehrkanalinjektionseinheit

Publications (1)

Publication Number Publication Date
DE102004034103A1 true DE102004034103A1 (de) 2005-04-28

Family

ID=34352886

Family Applications (2)

Application Number Title Priority Date Filing Date
DE102004021578A Withdrawn DE102004021578A1 (de) 2003-09-17 2004-05-03 Verfahren und Vorrichtung zur Abscheidung von ein-oder mehrkomponentigen Schichten und Schichtfolgen unter Verwendung von nicht-kontinuierlicher Injektion von flüssigen und gelösten Ausgangssubstanzen über eine Mehrkanalinjektionseinheit
DE102004034103A Withdrawn DE102004034103A1 (de) 2003-09-17 2004-07-15 Verfahren zur Abscheidung von Silizium und Germanium enthaltenen Schichten und Schichtfolgen unter Verwendung von nicht-kontinuierlicher Injektion von flüssigen und gelösten Ausgangssubstanzen über eine Mehrkanalinjektionseinheit

Family Applications Before (1)

Application Number Title Priority Date Filing Date
DE102004021578A Withdrawn DE102004021578A1 (de) 2003-09-17 2004-05-03 Verfahren und Vorrichtung zur Abscheidung von ein-oder mehrkomponentigen Schichten und Schichtfolgen unter Verwendung von nicht-kontinuierlicher Injektion von flüssigen und gelösten Ausgangssubstanzen über eine Mehrkanalinjektionseinheit

Country Status (4)

Country Link
US (1) US7732308B2 (de)
JP (1) JP4719679B2 (de)
DE (2) DE102004021578A1 (de)
TW (1) TW200513545A (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102014108352A1 (de) 2014-06-13 2015-12-17 Forschungszentrum Jülich GmbH Verfahren zum Abscheiden einer Kristallschicht bei niedrigen Temperaturen, insbesondere einer photolumineszierenden IV-IV-Schicht auf einem IV-Substrat, sowie ein eine derartige Schicht aufweisendes optoelektronisches Bauelement
DE102019008930A1 (de) * 2019-12-20 2021-06-24 Azur Space Solar Power Gmbh Gasphasenepitaxieverfahren
DE102019008927A1 (de) * 2019-12-20 2021-06-24 Azur Space Solar Power Gmbh Gasphasenepitaxieverfahren
DE102019008931A1 (de) * 2019-12-20 2021-06-24 Azur Space Solar Power Gmbh Gasphasenepitaxieverfahren

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102004015174A1 (de) * 2004-03-27 2005-10-13 Aixtron Ag Verfahren zum Abscheiden von insbesondere Metalloxiden mittels nicht kontinuierlicher Precursorinjektion
EP2215282B1 (de) 2007-10-11 2016-11-30 Valence Process Equipment, Inc. Cvd-reaktor
US9150961B2 (en) * 2009-11-16 2015-10-06 Fei Company Gas delivery for beam processing systems
DE102014115497A1 (de) * 2014-10-24 2016-05-12 Aixtron Se Temperierte Gaszuleitung mit an mehreren Stellen eingespeisten Verdünnungsgasströmen
US20170350752A1 (en) * 2016-06-01 2017-12-07 Ventsislav Metodiev Lavchiev Light emitting structures and systems on the basis of group iv material(s) for the ultraviolet and visible spectral ranges
KR102369676B1 (ko) 2017-04-10 2022-03-04 삼성디스플레이 주식회사 표시 장치의 제조장치 및 표시 장치의 제조방법

Family Cites Families (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL8702096A (nl) 1987-09-04 1989-04-03 Stichting Katholieke Univ Werkwijze en inrichting voor het mengen van gassen en het met behulp van een gasmengsel epitactisch vervaardigen van halfgeleiderproducten.
JP3149223B2 (ja) * 1991-10-07 2001-03-26 東京エレクトロン株式会社 成膜方法
JP3239622B2 (ja) * 1994-08-12 2001-12-17 松下電器産業株式会社 半導体薄膜の形成方法
JP3720083B2 (ja) * 1995-07-21 2005-11-24 株式会社日立製作所 半導体素子用薄膜の製造方法および装置、並びに半導体ウェハ
US6194038B1 (en) 1998-03-20 2001-02-27 Applied Materials, Inc. Method for deposition of a conformal layer on a substrate
US6194229B1 (en) 1999-01-08 2001-02-27 Micron Technology, Inc. Method for improving the sidewall stoichiometry of thin film capacitors
US6306211B1 (en) 1999-03-23 2001-10-23 Matsushita Electric Industrial Co., Ltd. Method for growing semiconductor film and method for fabricating semiconductor device
JP3823591B2 (ja) * 1999-03-25 2006-09-20 三菱電機株式会社 Ｃｖｄ原料用気化装置およびこれを用いたｃｖｄ装置
KR100273473B1 (ko) 1999-04-06 2000-11-15 이경수 박막 형성 방법
KR100319494B1 (ko) 1999-07-15 2002-01-09 김용일 원자층 에피택시 공정을 위한 반도체 박막 증착장치
DE10007059A1 (de) * 2000-02-16 2001-08-23 Aixtron Ag Verfahren und Vorrichtung zur Herstellung von beschichteten Substraten mittels Kondensationsbeschichtung
EP1266054B1 (de) 2000-03-07 2006-12-20 Asm International N.V. Gradierte dünne schichten
KR100363088B1 (ko) 2000-04-20 2002-12-02 삼성전자 주식회사 원자층 증착방법을 이용한 장벽 금속막의 제조방법
US20020030246A1 (en) 2000-06-28 2002-03-14 Motorola, Inc. Structure and method for fabricating semiconductor structures and devices not lattice matched to the substrate
DE10057491A1 (de) 2000-11-20 2002-05-23 Aixtron Ag Vorrichtung und Verfahren zum Zuführen eines in die Gasform gebrachten flüssigen Ausgangsstoffes in einen CVD-Reaktor
JP2002173777A (ja) 2000-12-01 2002-06-21 C Bui Res:Kk Ｃｖｄ装置の金属液体気化ユニット及び気化方法
DE10114956C2 (de) 2001-03-27 2003-06-18 Infineon Technologies Ag Verfahren zum Herstellen einer dielektrischen Schicht als Isolatorschicht für einen Grabenkondensator
DE10156932A1 (de) 2001-11-20 2003-05-28 Infineon Technologies Ag Verfahren zur Abscheidung dünner Praseodymoxid-Schichten mittels ALD/CVD-Verfahren
US6620670B2 (en) 2002-01-18 2003-09-16 Applied Materials, Inc. Process conditions and precursors for atomic layer deposition (ALD) of AL2O3
GB0212616D0 (en) 2002-05-31 2002-07-10 Univ Warwick Formation of lattice-tuning semiconductor substrates
KR20060079201A (ko) * 2003-09-17 2006-07-05 아익스트론 아게 불연속 주입을 이용한 층의 증착 방법 및 증착 장치

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102014108352A1 (de) 2014-06-13 2015-12-17 Forschungszentrum Jülich GmbH Verfahren zum Abscheiden einer Kristallschicht bei niedrigen Temperaturen, insbesondere einer photolumineszierenden IV-IV-Schicht auf einem IV-Substrat, sowie ein eine derartige Schicht aufweisendes optoelektronisches Bauelement
US10988858B2 (en) 2014-06-13 2021-04-27 Forschungszentrum Jülich GmbH Method for depositing a crystal layer at low temperatures, in particular a photoluminescent IV-IV layer on an IV substrate, and an optoelectronic component having such a layer
EP4043620A1 (de) 2014-06-13 2022-08-17 Forschungszentrum Jülich GmbH Verfahren zum abscheiden einer kristallschicht bei niedrigen temperaturen, insbesondere einer photolumineszierenden iv-iv-schicht auf einem iv-substrat, sowie ein eine derartige schicht aufweisendes optoelektronisches bauelement
DE102019008930A1 (de) * 2019-12-20 2021-06-24 Azur Space Solar Power Gmbh Gasphasenepitaxieverfahren
DE102019008927A1 (de) * 2019-12-20 2021-06-24 Azur Space Solar Power Gmbh Gasphasenepitaxieverfahren
DE102019008931A1 (de) * 2019-12-20 2021-06-24 Azur Space Solar Power Gmbh Gasphasenepitaxieverfahren
US11598022B2 (en) 2019-12-20 2023-03-07 Azur Space Solar Power Gmbh Vapor phase epitaxy method
US11955334B2 (en) 2019-12-20 2024-04-09 Azur Space Solar Power Gmbh Vapor phase epitaxy method
DE102019008927B4 (de) 2019-12-20 2024-04-11 Azur Space Solar Power Gmbh Gasphasenepitaxieverfahren
DE102019008931B4 (de) 2019-12-20 2024-04-11 Azur Space Solar Power Gmbh Gasphasenepitaxieverfahren

Also Published As

Publication number Publication date
JP2007506271A (ja) 2007-03-15
TW200513545A (en) 2005-04-16
DE102004021578A1 (de) 2005-04-21
US7732308B2 (en) 2010-06-08
US20090081853A1 (en) 2009-03-26
JP4719679B2 (ja) 2011-07-06
TWI368668B (de) 2012-07-21

Similar Documents

Publication Publication Date Title
ES2256948T3 (es) Procedimiento y dispositivo para el recubrimiento en fase de vacio de un sustrato.
CN101974734B (zh) 具有多层复合防护膜的基底材料的制备方法
DE102004034103A1 (de) Verfahren zur Abscheidung von Silizium und Germanium enthaltenen Schichten und Schichtfolgen unter Verwendung von nicht-kontinuierlicher Injektion von flüssigen und gelösten Ausgangssubstanzen über eine Mehrkanalinjektionseinheit
TWI264473B (en) Vacuum deposition device and vacuum deposition method
WO2006007313A3 (en) Improving water-barrier performance of an encapsulating film
KR101481863B1 (ko) 원자층 증착 도핑 방법
WO2006098792A3 (en) High accuracy vapor generation and delivery for thin film deposition
WO2006138103A3 (en) Method for silicon based dielectric chemical vapor deposition
WO2006057709A8 (en) Method for deposition of metal layers from metal carbonyl precursors
TW200618066A (en) Deposition of ruthenium metal layers in a thermal chemical vapor deposition process
TW200517522A (en) Chemical vapor deposition unit
TW200702476A (en) Low-temperature chemical vapor deposition of low-resistivity ruthenium layers
TW200733196A (en) Vaporizer, semiconductor manufacturing apparatus and manufacturing method thereof
WO2006019438A3 (en) Low-temperature plasma-enhanced chemical vapor deposition of silicon-nitrogen-containing films
WO2009136019A3 (fr) Dispositif et procede de traitement chimique en phase vapeur
TW200606168A (en) Copper (I) compounds useful as deposition precursors of copper thin films
CN108231538A (zh) 薄膜沉积方法
SG171631A1 (en) A method for the manufacture of a coating
MX2007005122A (es) Procedimiento de vapor quimico mejorado de plasma de velocidad de deposicion mejorada.
TW200502415A (en) Manufacturing apparatus
RU2007105817A (ru) Химическое осаждение из паровой фазы при атмосферном давлении
TW200730652A (en) Silicon body formation method and device thereof
WO2018212882A3 (en) METHOD FOR CONTROLLING THE CONSTRAINTS OF THIN FILMS LAID DOWN BY CVD FOR DISPLAY TYPE APPLICATION
US20150241386A1 (en) Gas sensor and method of manufacturing the same
RU2008138423A (ru) Способ и устройство для изготовления магниторезистивного элемента

Legal Events

Date Code Title Description
8181 Inventor (new situation)

Inventor name: SCHUMACHER, MARCUS, DR., 50171 KERPEN, DE

Inventor name: BAUMANN, PETER, DR., 52072 AACHEN, DE

Inventor name: MCENTEE, TIMOTHY, 52134 HERZOGENRATH, DE

Inventor name: LINDNER, JOHANNES, DR., 52072 AACHEN, DE

8127 New person/name/address of the applicant

Owner name: AIXTRON AG, 52134 HERZOGENRATH, DE

R012 Request for examination validly filed

Effective date: 20110709

R082 Change of representative

Representative=s name: RIEDER & PARTNER PATENTANWAELTE - RECHTSANWALT, DE

Representative=s name: RIEDER & PARTNER PATENTANWAELTE - RECHTSANWALT, 42

R081 Change of applicant/patentee

Owner name: AIXTRON SE, DE

Free format text: FORMER OWNER: AIXTRON AG, 52134 HERZOGENRATH, DE

Effective date: 20111104

R082 Change of representative

Representative=s name: RIEDER & PARTNER MBB PATENTANWAELTE - RECHTSAN, DE

Effective date: 20111104

Representative=s name: RIEDER & PARTNER PATENTANWAELTE - RECHTSANWALT, DE

Effective date: 20111104

R119 Application deemed withdrawn, or ip right lapsed, due to non-payment of renewal fee

Effective date: 20130201