Sök i LIBRIS databas



Sökning: onr:13589482 > Nano-semiconductors :

Nano-semiconductors : devices and technology /edited by Krzysztof Iniewski.

  • BokEngelska2012

Förlag, utgivningsår, omfång ...

  • Publicerad:Boca Raton, Fla.Publicerad:CRC ;Publicerad:London :Publicerad:Taylor & Francis [distributor],Publicerad:c2012.
  • xiv, 585 p.ill.25 cm.


  • LIBRIS-ID:13589482
  • ISBN:9781439848357
  • ISBN:1439848351

Kompletterande språkuppgifter

  • Språk:engelska



  • Devices, circuits, and systems.


  • Includes bibliographical references and index.
  • Contents: pt. I Semiconductor Materials -- ch. 1 Electrical Propagation on Carbon Nanotubes: From Electrodynamics to Circuit Models / Giovanni Miano -- 1.1.Introduction -- 1.2.Electrodynamics of CNTs -- 1.2.1.Generality -- 1.2.2.Band Structure of a CNT Shell -- 1.2.3.Constitutive Relation for a CNT Shell -- 1.2.4.Number of Effective Channels for SWCNTs and MWCNTs -- 1.3.An Electromagnetic Application: CNTs as Innovative Scattering Materials -- 1.3.1.Generality -- 1.3.2.Electromagnetic Models for CNT Scattering -- 1.4.Circuital Application: CNTs as Innovative Interconnects -- 1.4.1.CNTs in Nanointerconnects -- 1.4.2.TL Model for a CNT Interconnect -- 1.4.3.A Bundle of CNTs as Innovative Chip-to-Package Interconnects -- 1.5.Conclusions -- References -- ch. 2 Monolithic Integration of Carbon Nanotubes and CMOS / Huikai Xie -- 2.1.Introduction -- 2.1.1.CNT Synthesis -- 2.1.2.CMOS-CNT Integration Challenges and Discussion --
  • Contents note continued: 2.2.CNT Synthesis by Localized Resistive Heating on Mock-CMOS -- 2.2.1.Microheater Design -- 2.2.2.Device Fabrication and Microheater Characterization -- Fabrication -- Characterization -- 2.2.3.Room Temperature CNT Synthesis -- 2.3.Maskless Post-CMOS CNT Synthesis on Foundry CMOS -- 2.3.1.Integration Principles and Device Design -- 2.3.2.Device Fabrication and Characterization -- 2.3.3.On-Chip Synthesis of CNTs -- 2.3.4.Characterization of CNTs and Circuit Evaluations -- 2.4.Conclusion -- References -- ch. 3 Facile, Scalable, and Ambient--Electrochemical Route for Titania Memristor Fabrication / Nathan M. Neihart -- 3.1.Introduction -- 3.2.Theory and Device Operation -- 3.3.Applications of Memristors -- 3.4.Current Memristive Materials and Fabrication Technologies -- 3.5.Memristor Fabrication via Electrochemical Anodization -- 3.6.Test Results of Electrochemical Anodization-Based Memristors -- 3.7.Conclusions --
  • Contents note continued: References -- ch. 4 Spin Transport in Organic Semiconductors: A Brief Overview of the First Eight Years / Sandipan Pramanik -- 4.1.Introduction -- 4.1.1.Spintronics in Data Storage -- Read Heads -- Random Access Memory -- 4.1.2.Spintronics for Information Processing -- 4.1.3.Organic Semiconductor Spintronics -- 4.2.Basic Elements of Spin Transport and Implications for Organics -- 4.2.1.Spin Injection -- 4.2.2.Spin Relaxation -- Mechanism --'yakonov-Perel' Mechanism -- Mechanism -- Interaction -- 4.2.3.Spin Relaxation in Organics: General Considerations -- 4.2.4.Measurement of Spin Relaxation Length and Time: Spin Valve Devices -- 4.3.Spin Injection and Transport in Organics: Spin Valve Experiments -- 4.3.1.Organic Thin Films -- (T6) Thin Films -- 8-Hydroxyquinoline Aluminum (Alq3) Thin Films -- Organics --
  • Contents note continued: 4.3.2.Organic Nanowires -- 4.4.Spin Injection and Transport in Organics: Meservey-Tedrow Spin Polarized Tunneling, Two-Photon Photoemission (TPPE), and oSR Experiments -- 4.4.1.Meservey-Tedrow Spin Polarized Tunneling -- 4.4.2.TPPE Spectroscopy -- -- Injection and Transport Studies by TPPE Spectroscopy -- 4.4.3.Low-Energy Muon Spin Rotation -- -- of Spin Diffusion Length in Organics by oSR Spectroscopy -- 4.5.Outlook and Conclusion -- 4.5.1.Nonvolatile Memory and Magnetic Field Sensors -- 4.5.2.Spin Based Classical and Quantum Computing -- 4.5.3.Spin Based OLEDs -- Acknowledgment -- References -- pt. II Silicon Devices and Technology -- ch. 5 SiGe BiCMOS Technology and Devices / Edward Preisler -- 5.1.Introduction -- 5.2.SiGe HBT Device Physics -- 5.3.Applications Driving SiGe Development -- 5.4.SiGe Performance Metrics -- 5.5.Device Optimization and Roadmap --
  • Contents note continued: 5.6.Modern SiGe BiCMOS RF Platform Components -- 5.7.Conclusions -- Acknowledgments -- References -- ch. 6 Ultimate FDSOI Multigate MOSFETs and Multibarrier Boosted Gate Resonant Tunneling FETs for a New High-Performance Low-Power Paradigm / Aryan Afzalian -- 6.1.Simulation Algorithm -- 6.2.Gate Coupling Optimization in Nanoscale Nanowire MOSFETs: Electrostatic Versus Quantum Confinement -- 6.3.Physics of RT-FET -- 6.3.1.Influence of Barrier Width -- 6.4.Schottky Barrier RT-FET -- 6.5.Conclusions -- Acknowledgments -- References -- ch. 7 Development of 3D Chip Integration Technology / Katsuyuki Sakuma -- 7.1.Introduction -- 7.2.3D Integration Technology -- 7.2.1.Advantages of 3D Chip Integration -- 7.2.2.Limitations of 3D Chip Integration -- Management -- Complexity -- 7.2.3.Various Kinds of 3D Technology -- 7.2.4.Approaches for 3D Integration -- Approach -- Approach --
  • Contents note continued: 7.2.5.Key Enabling Technologies for 3D Chip Integration -- 7.3.Through-Silicon Via -- 7.3.1.Processing Flow for TSV -- 7.3.2.Via Etching -- 7.3.3.Insulation Layer -- 7.3.4.Barrier and Adhesion Layer -- 7.3.5.Conductive Materials for TSV -- 7.4.Bonding Technologies -- 7.4.1.Overview of Bonding Technologies -- 7.4.2.IMC Bonding -- System -- Materials for IMC Bonding -- 7.4.3.Characteristics of IMC Bonding -- Vehicle for Mechanical Evaluation of IMC Bonding -- Strength -- Test Reliability -- SEM and EDX Analysis -- Cycle Testing with IMC Bonding -- 7.4.4.Fluxless Bonding -- Plasma Treatment -- UV Treatment -- Acid Treatment -- Radical Treatment -- of Surface Treatments -- 7.5.Die-to-Wafer Integration Technology -- 7.5.1.Die Yield of Stacking Processes --
  • Contents note continued: 7.5.2.Die Cavity Technology -- 7.5.3.Alignment Accuracy -- 7.5.4.Test Vehicle: Design and Features -- 7.5.5.Results of Stacking Using Die Cavity Technology -- 7.5.6.Electrical Tests -- 7.6.Underfill Encapsulation for 3D Integration -- 7.6.1.Overview of Underfill Process -- 7.6.2.Vacuum Underfill Process -- 7.6.3.Results of Vacuum Underfill for 3D Chip Stack -- 7.7.Summary -- Acknowledgments -- References -- ch. 8 Embedded Spin-Transfer-Torque MRAM / Kangho Lee -- 8.1.Introduction -- 8.1.1.Motivation for Embedded STT-MRAM: Application Perspectives -- 8.1.2.Recent Industrial Efforts for MRAM Development -- 8.2.Magnetic Tunnel Junction: Storage Element of STT-MRAM -- 8.2.1.Magnetization Dynamics in Ferromagnetic Metals -- 8.2.2.Tunneling Magnetoresistance Ratio -- 8.2.3.Energy Barrier for Data Retention -- 8.2.4.Spin-Transfer-Torque (STT Switching) -- 8.3.1T-1MTJ STT-MRAM BITCELL -- 8.3.1.Read Margin -- 8.3.2.Write Margin --
  • Contents note continued: 8.4.MTJ Material Engineering for Write Power Reduction -- 8.4.1.Perpendicular Magnetic Anisotropy -- 8.4.2.Damping Constant and STT Efficiency -- References -- ch. 9 Nonvolatile Memory Device: Resistive Random Access Memory / Qingqing Sun -- 9.1.Introduction -- 9.1.1.Resistive Random Access Memory: History and Emerging Technology -- 9.1.2.Challenge for RRAM on Storage-Class Memory -- Requirement -- 9.1.3.Architecture Requirement -- 9.2.BTMO-Based RRAM -- 9.2.1.Device Fabrication and Current-Voltage Characterization -- Fabrication -- Characterization -- 9.2.2.BTMO RRAM Integration for Embedded Application on 0.18 om Al Process and 0.13 om Cu Process -- Integration on 0.18 om Al Process -- Integration on 0.13 om Cu Process -- 9.2.3.Doping Effect in BTMO RRAM -- 9.2.4.Role of Compliance Current -- 9.2.5.Physical Mechanism and Its Evidence --
  • Contents note continued: 9.3.Memristor -- 9.3.1.Leon Chua's Theory of Fourth Fundamental Element -- 9.3.2.HP Laboratories' Discovery of Prototype Pt/TiO2-x/TiO2/Pt Memristor -- 9.4.Conclusion -- References -- ch. 10 DRAM Technology / Myoung Jin Lee -- 10.1.Introduction to Dynamic Random Access Memory -- 10.1.1.DRAM Cell -- 10.1.2.Sense Operation -- 10.2.Sensing Margin in DRAM -- 10.2.1.Definition of Sensing Margin -- 10.2.2.Noise Effect on Sensing Margin -- Cell Performance (Leakage and Current Drivability) -- DRAM Cell Structures -- Mismatch in BLSA -- Noise in Accordance with Data Pattern -- 10.2.3.Relation between Refresh Time and Sensing Noise in Accordance with Data Pattern -- 10.2.4.How to Improve Sensing Margin -- Compensation Sense Amplifier -- References -- ch. 11 Monocrystalline Silicon Solar Cell Optimization and Modeling / Victor Moroz -- 11.1.Introduction --
  • Contents note continued: 11.2.Modeling Optical Effects -- 11.2.1.Textured Surface -- 11.2.2.Behavior of Different Light Wavelengths -- 11.2.3.Optical Performance of Regular Surface Patterns -- 11.2.4.Regular versus Random Texture -- 11.3.Modeling Electronic Effects -- 11.3.1.Definition of Simulation Cell Structure -- Definition -- Strategy -- 11.3.2.Modeling Methodology -- of Optical Reflectivity on Optically Generated Carrier Profile -- Recombination Rate -- Resistance -- Recombination -- 11.3.3.Current Crowding -- 11.3.4.Optimizing Efficiency of Solar Cell -- 11.3.5.Comparing 3D with 2D and 1D -- 11.3.6.Junction Optimization -- 11.4.Conclusions -- References -- ch. 12 Radiation Effects on Silicon Devices / Alessandro Paccagnella -- 12.1.Introduction -- 12.2.Radiation Environments -- 12.2.1.Space -- 12.2.2.Terrestrial Environment -- 12.2.3.Man-Made Radiation -- 12.3.TID EFFECTS --
  • Contents note continued: 12.3.1.MOSFETs -- 12.3.2.Bipolar Devices -- 12.4.Displacement Damage -- 12.4.1.Charge-Coupled Devices -- 12.5.Single Event Effects -- 12.5.1.Single Event Upsets in SRAMs -- 12.5.2.SEEs in Flash Cells -- 12.6.Conclusions -- References -- pt. III Compound Semiconductor Devices and Technology -- ch. 13 GaN/InGaN Double Heterojunction Bipolar Transistors Using Direct-Growth Technology / Russell Dean Dupuis -- 13.1.Introduction -- 13.2.GaN/InGaN HBT Design -- 13.3.GaN/InGaN HBT Epitaxial Growth and Fabrication Techniques -- 13.4.State-of-the-Art Direct-Growth GaN/InGaN DHBTs -- 13.4.1.Impact of Indium in InGaN Base Layer -- 13.4.2.Burn-In Effect -- 13.4.3.High-Performance GaN/InGaN DHBT -- 13.5.Technology Development Trends for III-N HBTs -- References -- ch. 14 GaN HEMTs Technology and Applications / Subramaniam Arulkumaran -- 14.1.Introduction -- 14.2.Device Types and Structures -- 14.2.1.Conventional GaN HEMTs with Cap Layer -- 14.2.2.Advanced GaN HEMTs --
  • Contents note continued: with A1N Spacer Layer -- Heterostructure HEMTs -- Matched InA1N/GaN HEMTs -- Barrier HEMTs -- GaN/AlGaN HEMTs -- Plate Assisted GaN HEMTs -- Metal-Insulators-Semiconductor HEMTs -- 14.3.Device Fabrication -- 14.3.1.Mesa Isolation -- 14.3.2.Ohmic-Contact Formation -- 14.3.3.Gate Formation by EBL -- 14.3.4.Device Passivation -- 14.3.5.Substrate Thinning and Via-Hole Formation -- 14.4.Device Performance -- 14.4.1.Effects of Passivation -- and Pulse I-V Characteristics -- Characteristics -- 14.4.2.Temperature-Dependent Characteristics -- Characteristics -- Characteristics -- 14.5.GaN HEMT Applications -- 14.5.1.GaN Hybrid Amplifiers -- 14.5.2.GaN MMICs -- References --
  • Contents note continued: ch. 15 Surface Treatment, Fabrication, and Performances of GaN-Based Metal-Oxide-Semiconductor High-Electron Mobility Transistors / Ching-Ting Lee -- 15.1.Introduction -- 15.2.Ohmic Contacts on GaN-Based Semiconductors -- 15.3.Gate Oxides: Materials and Deposition Methods -- 15.4.Surface Treatment of GaN-Based Semiconductors -- 15.4.1.Sulfidation Method -- 15.4.2.Chlorination Method -- 15.4.3.PEC Method -- 15.5.GaN-Based Metal-Oxide-Semiconductor Devices -- 15.6.GaN-Based MOSHEMTs -- 15.7.Conclusions -- References -- ch. 16 GaN-Based HEMTs on Large-Diameter Si Substrate for Next Generation of High Power/High Temperature Devices / Farid Medjdoub -- 16.1.Introduction -- 16.2.GaN-on-Si Devices for High Power at High Frequency -- 16.2.1.DC Characteristics -- 16.2.2.Dynamic Characteristics -- 16.3.GaN on Silicon Devices for Harsh Environment -- 16.4.GaN Power Transistors on Silicon Substrate for Switching Application --
  • Contents note continued: 16.4.1.Ultrathin Barrier Device Design and Fabrication -- 16.4.2.Results and Discussion -- 16.5.Reliability Aspects -- 16.5.1.Thermal Stability Enhancement via In Situ Si3N4 Cap Layer -- 16.5.2.Reliability Test on Power Switching Devices -- and Test Description -- Stress -- 16.5.3.Reliability Test on RF Devices -- 16.6.Conclusions -- References -- ch. 17 GaAs HBT and Power Amplifier Design for Handset Terminals / Kazuya Yamamoto -- 17.1.Introduction -- 17.2.Basics of GaAs-Based HBTs -- 17.2.1.Principle of Operation -- 17.2.2.DC and RF Characteristics -- 17.2.3.Role of Ballasting Resistors and VSWR Ruggedness -- 17.3.Linear Power Amplifier Design for Handset Terminals -- 17.3.1.Basic Bias Circuit Topology -- 17.3.2.Bias Drive and AM-AM/AM-PM Characteristics -- 17.3.3.Bias Circuits and AM-AM/AM-PM Characteristics -- 17.3.4.Harmonic Terminations and AM-AM/AM-PM Characteristics --
  • Contents note continued: 17.3.5.Circuit Design Example for Two-Stage Power Amplifier -- 17.4.Summary -- References -- ch. 18 Resonant Tunneling and Negative Differential Resistance in III-Nitrides / Vladimir Litvinov -- 18.1.Introduction -- 18.2.Single-Layer Devices -- 18.3.Resonant Tunneling Diodes -- 18.3.1.Current-Voltage Characteristics -- 18.4.Superlattices -- 18.4.1.Domain Oscillations and SL-Based High Frequency Sources -- 18.4.2.Conduction Band Profile and Field-Mobility Relation -- 18.4.3.Circuit Design -- 18.4.4.Traveling Electrical Domains -- 18.4.5.Power Oscillations and Their Spectral Content -- 18.4.6.Power Efficiency -- 18.5.Fabrication and DC Characterization of AlxGa1-xN/GaN SL Diodes -- Acknowledgment -- References -- ch. 19 New Frontiers in Intersubband Optoelectronics Using III-Nitride Semiconductors / Eva Monroy -- 19.1.Introduction to ISB Optoelectronics -- 19.2.III-Nitride Materials for Near-IR Optoelectronics -- 19.2.1.Electronic Structure --
  • Contents note continued: 19.2.2.Growth and Structural Properties -- 19.2.3.Optical Characterization -- Characterization -- Absorption -- 19.2.4.Polarization-Induced Doping -- 19.2.5.GaN/A1N Quantum Dots -- 19.2.6.A1InN/GaN System -- 19.2.7.Semipolar III-Nitrides -- 19.2.8.Cubic III-Nitrides -- 19.3.Devices Operating in Near-IR -- 19.3.1.All-Optical Switches -- 19.3.2.Infrared Photodetectors -- 19.3.3.Electro-Optical Modulators -- 19.3.4.Toward Light Emitters -- 19.4.Toward Longer Wavelengths -- 19.5.Conclusions and Perspectives -- References.

Ämnesord och genrebeteckningar

Biuppslag (personer, institutioner, konferenser, titlar ...)

  • Iniewski, Krzysztof.(författare)

Länkade data-URI:er (test)

  • (Nanoteknik sao)
  • (Halvledare sao)
Inställningar Hjälp

Vad är fjärrlån?

Finns inte boken du söker på ditt bibliotek? Då kan biblioteket i många fall låna in den från ett annat bibliotek genom ett så kallat fjärrlån.

För ett trettiotal bibliotek kan man själv som låntagare göra beställningar direkt via ett formulär i LIBRIS (LIBRIS låntagarbeställningar), dessa bibliotek är listade nedan. Mer om fjärrlån

Många bibliotek erbjuder beställningsformulär för fjärrlån på sina webbplatser. Kontakta ditt bibliotek för mer information.

Bibliotek som erbjuder tjänsten LIBRIS låntagarbeställningar

Lunds universitets bibliotek, Geobiblioteket
Lunds universitets bibliotek, Juridiska fakultetens bibliotek
Lunds universitets bibliotek, Musikhögskolan i Malmö, biblioteket
Åtvidabergs kommunbibliotek
Enskilda Högskolan Stockholm, Biblioteket
Ekerö biblioteket
Eksjö stadsbibliotek
Eslövs stadsbibliotek
Brinellskolan, Biblioteket
Falkenbergs bibliotek
Färgelanda kommunbibliotek
Finspångs bibliotek
Högskolan i Gävle, biblioteket
Gnosjö bibliotek
Chalmers tekniska högskola, Huvudbiblioteket
Göteborgs universitetsbibliotek Biomedicinska biblioteket
Göteborgs universitetsbibliotek Botanik- och miljöbiblioteket
Göteborgs universitetsbibliotek Ekonomiska biblioteket
Göteborgs universitetsbibliotek Humanistiska biblioteket
Göteborgs universitetsbibliotek Konstbiblioteket
Göteborgs universitetsbibliotek Pedagogiska biblioteket
Göteborgs universitetsbibliotek Samhällsvetenskapliga biblioteket
Halmstads stadsbibliotek
Högskolan i Halmstad, biblioteket
Haninge bibliotek, Handen
Haparanda stadsbibliotek
Härnösands bibliotek
Lunds universitets bibliotek, Campus Helsingborg, biblioteket
Orusts kommunbibliotek
Herrljunga folkbibliotek
Huddinge bibliotek
Södertörns högskolebibliotek
Kinda bibliotek
Högskolan Kristianstad
Kungsbacka bibliotek
Lidingö stadsbibliotek
Linköpings stadsbibliotek
Sveriges lantbruksuniversitets bibliotek, SLU-biblioteket i Alnarp
Norrbottens museum, Biblioteket
Universitetsbiblioteket vid Luleå tekniska universitet
Lunds universitets bibliotek, Asienbiblioteket, HT-biblioteken
Lunds universitets bibliotek, Biblioteket för arkitektur och design, LTH
Lunds universitets bibliotek, Biologibiblioteket
Lunds universitets bibliotek, E-husets bibliotek, LTH
Lunds universitets bibliotek, Ekonomihögskolans bibliotek
Lunds universitets bibliotek, Fysik- och astronomibiblioteket
Lunds universitets bibliotek, HT-biblioteken, LUX-biblioteket (Humanist- och teologcentrum)
Lunds universitets bibliotek, Internationella miljöinstitutets bibliotek
Lunds universitets bibliotek, Kemicentrums bibliotek
Lunds universitets bibliotek, LTH studiecentrum
Lunds universitets bibliotek, Medicinska fakultetens bibliotek Lund
Lunds universitets bibliotek, Raoul Wallenberginstitutets bibliotek
Lunds universitets bibliotek, Samhällsvetenskapliga fakultetens bibliotek
Lunds universitets bibliotek, SOL-biblioteket
Lunds universitets bibliotek, V-husets bibliotek, LTH
Lunds universitets bibliotek, Medicinska fakulteten i Malmö, biblioteket
Mjölby kommun biblioteket
Motala bibliotek
Nordmalings bibliotek
Norrköpings stadsbibliotek
Nykvarns bibliotek
Nynäshamn kommun, Nynäshamns bibliotek
Ödeshögs kommunbibliotek
Mittuniversitetet, Biblioteket i Östersund
Tornedalens bibliotek
Pajala kommunbibliotek
Universitetsbiblioteket vid Luleå tekniska universitet, Biblioteket för musik och medier
Salems bibliotek
Simrishamns bibliotek
Campusbiblioteket Skellefteå
Högskolan i Skövde, biblioteket
Skurups kommunbibliotek
Söderköpings bibliotek
Biblioteken i Södertälje
Anna Lindh-biblioteket
Anna Lindh-biblioteket, biblioteket på Högkvarteret
Anna Lindh-biblioteket, filialen på Militärhögskolan Karlberg
FMV, Biblioteket
Konstfacks bibliotek
Kungliga biblioteket
Riksantikvarieämbetet - Vitterhetsakademiens bibliotek
Strömsnäsbruks bibliotek
Mittuniversitetet, Biblioteket i Sundsvall
Sundsvalls stadsbibliotek
Svenljunga kommunbibliotek
Tranemo bibliotek
Högskolan Väst, Biblioteket
Sveriges lantbruksuniversitets bibliotek, SLU-biblioteket i Umeå
Umeå stadsbibliotek, Lär/Fjärrlån
Sveriges lantbruksuniversitets bibliotek, SLU-biblioteket i Uppsala
Uppsala universitetsbibliotek, Ångströmbiblioteket
Uppsala universitetsbibliotek, Biologibiblioteket
Uppsala universitetsbibliotek, Blåsenhusbiblioteket
Uppsala universitetsbibliotek, BMC-biblioteket
Uppsala universitetsbibliotek, Dag Hammarskjöld och Juridiska biblioteket
Uppsala universitetsbibliotek, Ekonomikums bibliotek
Uppsala universitetsbibliotek, Geo-biblioteket
Uppsala universitetsbibliotek, Karin Boye-biblioteket
Uppsala universitetsbibliotek, Medicinska biblioteket
Vadstena bibliotek
Campusbiblioteket i Varberg
Varbergs bibliotek
Vårgårda bibliotek
Vindelns bibliotek
Visby (paket över 2 kg skickas till besöksadressen)
Uppsala universitetsbibliotek, Almedalsbiblioteket

Sök utanför LIBRIS

Fel i posten?
Teknik och format
Sök utifrån
LIBRIS söktjänster

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

Copyright © LIBRIS - Nationella bibliotekssystem

pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy