Si/SiGe resonant tunnel diode

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A Si/SiGe resonant tunnel diode is a resonant tunnel diode based on Si/SiGe heterojunctions. Both hole tunneling and electron tunneling have been observed. But the performance of Si/SiGe resonant tunnel diode is limited mainly because of the limited band edge discontinuity in both the valence band and the conduction band.

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[edit] Hole Tunneling

Resonant tunneling of holes through Si/SiGe heterojunctions was attempted first because of the typically relatively larger valence band discontinuity in Si/SiGe heterojunctions than the conduction band discontinuity for (compressively) strained Si1-xGex layers grown on Si substrates. This has been observed, but negative differential resistance was only observed at low temperatures (peak to valley current ratio of 1.5 at 77 K, and 2 at 4 K) and not at room temperature.[1]

[edit] Electron Tunneling

Resonant tunneling of electrons through Si/SiGe heterojunctions was obtained later, with a limited peak-to-valley current ratio (PVCR) of 1.2 at room temperature.[2] Subsequent developments have realized Si/SiGe RTDs (electron tunneling) with a PVCR of 2.9 with a PCD of 4.3 kA/cm2[3] and a PVCR of 2.43 with a PCD of 282 kA/cm² at room temperature.[4]

[edit] References

  1. ^  U. Gennser, V.P. Kesan, S.S. Iyer, T.J. Bucelot, and E.S. Yang, J. Vac. Sci. Technol. B 8, 210 (1990)
  2. ^  K. Ismail, B.S. Meyerson, and P.J. Wang, Electron resonant tunneling in Si/SiGe double barrier diodes, Appl. Phys. Lett. 59, 973 (1991)
  3. ^  P. See, D.J. Paul, B. Hollander, S. Mantl, I. V. Zozoulenko, and K.-F. Berggren, High Performance Si/Si1 xGex Resonant Tunneling Diodes, IEEE Electron Device Letters 22, 182 (2001)
  4. ^  P. See and D.J. Paul, The scaled performance of Si/Si1-xGexresonant tunneling diodes, IEEE Electron Device Letters 22, 582 (2001)

[edit] See also