Si/SiGe electron resonant tunneling diodes

Resonant tunneling diodes have been fabricated using strained-Si wells and strained Si0.4Ge0.6 barriers on a relaxed Si0.8Ge0.2 n-type substrate, whic h demonstrate negative differential resistance at 298 K. Peak current densi ties of 5 kA/cm(2) with peak-to-valley current ratios of 1.1 have been achi eved. Theoretical modeling of the structure demonstrates that the major cur rent peak results from the tunneling of light-mass electrons from the relax ed substrate and not from the heavy-mass electrons in the emitter accumulat ion layer. (C) 2000 American Institute of Physics. [S0003- 6951(00)02337-8] .