InAs-based nanowires on silicon platform for novel nanoscale high electron mobility heterojunction devices

• Applicant: Privatdozent Dr. Gregor Koblmüller
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2012 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 212579533

• Final Report Year: 2017

Final Report Abstract

Within this project, important fundamental knowledge could be gained about the electronic properties and electrical transport characteristics of III-V based nanowires (NW) integrated on silicon (Si). Based on extensive growth optimization studies of catalyst-free InAs and InGaAs NWs we were able to tune many intrinsic parameters, such as size, alloy composition, defect and surface state densities and interface quality of the relevant NW charge carrier channel. The impact of these parameters was reflected in the transport characteristics of fabricated NW- FETs, as well as in heterojunction devices such as NW/Si tunnel diodes. Excellent Esaki diode characteristics with high peak-to-valley current ratios and very high tunnel currents across n- InAs-NW/p++-Si heterojunctions were obtained, providing promising building blocks for vertically integrated NW-Si tunneling FETs. In addition, we explored the concept of modulation doping in radial core-shell NW heterostructures to obtain high-electron mobility NW transistor devices. We successfully demonstrated for the first time in III-V-based NW-FETs the formation of a high-mobility two-dimensional electron gas (2DEG) that further enabled observation of excellent dc output and transfer characteristics with sub-threshold slopes close to the theoretical limit. These concepts have proven to be versatile nanoscale systems that shall be further exploited for nanoelectronic applications in future research.

Publications

• Diameter dependent optical emission properties of InAs nanowires grown on Si. Applied Physics Letters 101, 053103 (2012)
  G. Koblmüller, K. Vizbaras, S. Hertenberger, S. Bolte, D. Rudolph, J. Becker, M. Döblinger, M.-C. Amann, J. J. Finley, and G. Abstreiter
  
• High compositional homogeneity in In-rich InGaAs nanowire arrays on nanoimprinted SiO2/Si(111). Applied Physics Letters 101, 043116 (2012)
  S. Hertenberger, S. Funk, K. Vizbaras, A. Yadav, D. Rudolph, J. Becker, S. Bolte, M. Döblinger, M. Bichler, G. Scarpa, P. Lugli, I. Zardo, J. J. Finley, M.-C. Amann, G. Abstreiter, and G. Koblmüller
  
• Rate-limiting mechanisms in high-temperature growth of catalyst-free InAs nanowires with large thermal stability. Nanotechnology 23, 235602 (2012)
  S. Hertenberger, D. Rudolph, J. Becker, M. Bichler, J. J. Finley, G. Abstreiter, and G. Koblmüller
  
• Size, composition, and doping effects on In(Ga)As nanowire/Si tunnel diodes probed by conductive atomic force microscopy. Applied Physics Letters 101, 233102 (2012)
  T. Yang, S. Hertenberger, S. Morkötter, G. Abstreiter, and G. Koblmüller
  
• E1(A) electronic band gap in wurtzite InAs nanowires studied by resonant Raman scattering. Nano Letters 13, 3011 (2013)
  I. Zardo, S. Yazji, N. Hörmann, S. Hertenberger, S. Funk, S. Mangialardo, S. Morkötter, G. Koblmüller, P. Postorino, and G. Abstreiter
  
• Enhanced luminescence properties of InAs-InAsP core-shell nanowires. Nano Letters 13, 6070 (2013)
  J. Treu, M. Bormann, H. Schmeiduch, M. Döblinger, S. Morkötter, S. Matich, P. Wiecha, K. Saller, B. Mayer, M. Bichler, M.-C. Amann, J. J. Finley, G. Abstreiter, and G. Koblmüller
  
• High-mobility one- and two-dimensional electron systems in nanowire-based quantum heterostructures. Nano Letters 13, 6189 (2013)
  S. Funk, M. Royo, I. Zardo, D. Rudolph, S. Morkötter, B. Mayer, J. Becker, A. Bechtold, S. Matich, M. Döblinger, M. Bichler, G. Koblmüller, J. J. FInley, A. Bertoni, G. Goldoni, and G. Abstreiter
  
• Role of microstructure on optical properties in high-uniformity InGaAs nanowire arrays: Evidence of a wider wurtzite band gap. Physical Review B 87, 205303 (2013)
  S. Morkötter, S. Funk, M. Liang, M. Döblinger, S. Hertenberger, J. Treu, D. Rudolph, A. Yadav, J. Becker, M. Bichler, G. Scarpa, P. Lugli, I. Zardo, J. J. Finley, G. Abstreiter, and G. Koblmüller
  
• Growth and properties of InGaAs nanowires on silicon. Physica Status Solidi – Rapid Review Letters (Invited Review) 8, 11 (2014)
  G. Koblmüller and G. Abstreiter
  
• Demonstration of confined electron gas and steep-slope behaviour in delta-doped GaAs-AlGaAs core-shell nanowire transistors. Nano Letters 15, 3295 (2015)
  S. Morkötter, N. Jeon, D. Rudolph, B. Loitsch, D. Spirkoska, E. Hoffmann, M. Döblinger, S. Matich, J. J. Finley, L. J. Lauhon, G. Abstreiter, and G. Koblmüller
  
• Lattice-matched InGaAs-InAlAs core-shell nanowires with improved luminescence and photoresponse properties. Nano Letters 15, 3533 (2015)
  J. Treu, T. Stettner, M. Watzinger, S. Morkötter, M. Döblinger, S. Matich, K. Saller, M. Bichler, G. Abstreiter, J. J. Finley, J. Stangl, and G. Koblmüller
  
• Photocurrents in a single InAs nanowire/Si heterojunction. ACS Nano 9, 9849 (2015)
  A. Brenneis, J. Overbeck, J. Treu, S. Hertenberger, S. Morkötter, M. Döblinger, J. J. Finley, G. Abstreiter, G. Koblmüller, and A. W. Holleitner
  
• Direct measurements of Fermi level pinning at the surface of intrinsically n-type InGaAs nanowires. Nano Letters 16, 5135 (2016)
  M. Speckbacher, J. Treu, T. J. Whittles, W. M. Linhart, X. Xu, K. Saller, V. R. Dhanak, G. Abstreiter, J. J. Finley, T. D. Veal, and G. Koblmüller
  
• Widely tunable alloy composition and crystal structure in catalyst-free InGaAs nanowire arrays grown by selective area molecular beam epitaxy. Applied Physics Letters 108, 053110 (2016)
  J. Treu, M. Speckbacher, K. Saller, S. Morkötter, M. Döblinger, X. Xu, H. Riedl, G. Abstreiter, J. J. Finley, and G. Koblmüller