Si/SiGe resonant tunnel diode

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.

Hole Tunneling

Resonant tunneling of holes through Si/SiGe heterojunctions was attemptedfirst because of the typically relatively larger valence band discontinuityin Si/SiGe heterojunctions than the conduction band discontinuity for(compressively) strained Si_1-xGe_x layers grown on Si substrates.This has been observed, but negative differential resistancewas 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.ref|Gennser90

Electron Tunneling

Resonant tunneling of electrons through Si/SiGe heterojunctionswas obtained later, with a limited peak-to-valley current ratio (PVCR)of 1.2 at room temperature.ref|Ismail91 Subsequent developments haverealized Si/SiGe RTDs (electron tunneling) with a PVCR of 2.9 with a PCD of 4.3kA/cm²ref|See01a and a PVCR of 2.43 with a PCD of 282 kA/cm²at room temperature.ref|See01b

References

# U. Gennser, V.P. Kesan, S.S. Iyer, T.J. Bucelot, and E.S. Yang, J. Vac. Sci. Technol. B 8, 210 (1990)
# K. Ismail, B.S. Meyerson, and P.J. Wang, Electron resonant tunneling in Si/SiGe double barrier diodes, Appl. Phys. Lett. 59, 973 (1991)
# 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)
# P. See and D.J. Paul, The scaled performance of Si/Si1-xGexresonant tunneling diodes, IEEE Electron Device Letters 22, 582 (2001)

See also

*Si Esaki tunnel diode
*Si/SiGe resonant interband tunnel diode