Technology development for III-V tunnel FETs on a silicon platform

Partners: IBM, EPFL

Accomplished Results

  • InAs-Si heterojunction nanowire (NW) TFETs were successfully demonstrated and analysed, with good overall performance in terms of trade-off between high Ion versus small slope and high Ion/Ioff ratio, cf. D2.4, M2.5. (Ion ≈ 2.4 μA/μm, Ion/Ioff ≈ 106, slope of 150 mV/dec over three decades) [1,2]
  • InAs-Si heterojunction NW tunnel diodes with excellent performance were achieved highlighting the benefits of the InAs-Si heterostructure for TFETs. Very high tunnel currents of 6 MA/cm2 at 0.5 V reverse bias and negative differential resistance in forward bias with high peak current density of up to 570 kA/cm2 was demonstrated. [3,4]
  • In-situ doping of InAs NWs up to a concentration of 7∙1019 cm-3 has been successfully established [5]
  • Seebeck measurements have been applied to derive the charge carrier density and together with NW resistance measurements the mobility. [5, 6]
  • Ni-alloyed InAs contacts with low contact resistance were demonstrated. [5]
  • Tunnel spectroscopy was applied to investigate the InAs-Si tunnel junction. [7]
  • A new growth approach based on selective epitaxy in nanotube templates was successfully developed to integrate III-V materials on a Si platform for TFETs. [8, 9]
  • Scaled diameters of 25 nm and high yield in nanowire growth and functioning TFET devices was achieved. [9]
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Fig. 1: Schematic of InAs-Si (a) tunnel diode and (b) TFET. (c) SEM image showing a heterojunction NW. The InAs NW is grown on Si <111> by selective area growth [10].
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Fig. 1 (d): HR-TEM image of the InAs-Si interface. (e) FIB cut of InAs-Si TFET. [1, 4]
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Fig. 2: Resistivity versus doping concentration of InAs NWs. [5]
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Fig. 3: InAs-Si Esaki diodes. Influence of the n-doping level in InAs. [4]
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Fig. 4: InAs-Si nanowire TFET (A) Temperature dependence of Ion at VG=-1V. (B) TFET Ion vs VG before and after Ni-alloying. [1]
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Fig. 5: Integration of III-V materials on Si. Epitaxial growth of InAs NWs and InAs-InSb NW heterojunctions within a template. (a) InAs NW within template. (b) Selective growth of InSb on InAs. The SEM image on the right of the array shows a NW with the template removed. (c) InSb growth extending out of the template. Scale bar is 100 nm. [8]

References

  1. K. E. Moselund, H. Schmid, C. Bessire, M. T. Björk, H. Ghoneim, H. Riel "InAs–Si Nanowire Heterojunction Tunnel FETs", IEEE Electron Device Letters, Vol. 33 (10), 1453–1455, 2012.
  2. H. Schmid, K. E. Moselund, M. T. Björk, M. Richter, H. Ghoneim, C. D. Bessire and H. Riel, "Fabrication of Vertical InAs-Si Heterojunction Tunnel Field Effect Transistors", IEEE 69th Device Research Conference Digest, 181–182, 2011.
  3. IM. T. Björk, H. Schmid, C. D. Bessire, K. E. Moselund, H. Ghoneim, E. Lörtscher, S. Karg, H. Riel "Si–InAs heterojunction Esaki tunnel diodes with high current densities", Appl. Phys. Lett. 97, 163501, 2010.
  4. H. Riel, K. E. Moselund, C. Bessire, M. T. Björk, A. Schenk, H. Ghoneim, H. Schmid, "InAs-Si Heterojunction Nanowire Tunnel Diodes and Tunnel FETs", Proc. of IEEE IEDM 2012.
  5. H. Ghoneim, P. Mensch, H. Schmid, C. Bessire, R.Rhyner, A. Schenk, C. Rettner, S. Karg, K. E. Moselund, H. Riel, M. Björk "In situ doping of catalyst-free InAs nanowires", Nanotechnology 23 505708, 2012.
  6. S. Karg, P. Mensch, H. Schmid, P. Das Kanungo, H. Ghoneim, V. Schmidt, M. Björk, V. Troncale, H. Riel, "Measurement of Thermoelectric Properties of Single Semiconductor Nanowires", Journal of Electronic Materials, Vol. 42(7), p. 2409-2414, 2013.
  7. C. D. Bessire, M. T. Björk, H. Schmid, A. Schenk, K. B. Reuter, and H. Riel, "Trap-Assisted Tunneling in Si-InAs Nanowire Heterojunction Tunnel Diodes", Nano Letters Vol. 11(10), 4195–9, 2011.
  8. P. Das Kanungo, H. Schmid, M. T. Björk, L. M. Gignac, C. Breslin, J. Bruley, C. D. Bessire and H. Riel, "Selective Area Growth of III-V Nanowires on Silicon in a Nanotube Template: Towards Monolithic Integration of Nano-Devices", Nanotechnology, Vol. 24(22), p. 225304, 2013.
  9. M. Borg, H. Schmid, K. E. Moselund, G. Signorello, L. Gignac, J. Bruley, C. Breslin, P. Das Kanungo, P. Werner, H. Riel, submitted.
  10. M. T. Björk, H. Schmid, C. Breslin, L. Gignac, H. Riel "InAs Nanowire Growth on <111> Silicon", J. Cryst. Growth, Vol. 344, Issue 1, 31–37, 20124] H. Riel, K. E. Moselund, C. Bessire, M. T. Björk, A. Schenk, H. Ghoneim, H. Schmid, "InAs-Si Heterojunction Nanowire Tunnel Diodes and Tunnel FETs", Proc. of IEEE IEDM 2012.