A Si/SiGe resonant tunnel diode
is a resonant tunnel diode
based on Si
. 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.
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-x
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.
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. Subsequent developments have
realized Si/SiGe RTDs (electron tunneling) with a PVCR of 2.9 with a PCD of 4.3
and a PVCR of 2.43 with a PCD of 282 kA/cm²
at room temperature.
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- 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)