Abstract: I-V curves of a 35nm p-type Si/Si1-xGex resonant tunneling diode (RTD) are simulated with the quantum hydrodynamic (QHD) model.An integrated difference scheme including the Schafetter-Gummel method,second upwind method,and second-order central difference method is used to discretize the QHD equations,maintaining both accuracy and stability.Investigations of some structural modifications are also carried out.The analytical results indicate that both quantum barrier thickness and hole effective mass affect the NDR characteristics of Si/Si1-xGex RTDs.The simulated peak-to-valley current ratio of 1.14 at 293K agrees with the experimental result when x=0.23.

Key words: Si/Si1-xGex resonant tunneling diode, quantum hydrodynamic model, discretization scheme, heavy- and light-hole, peak-to-valley current ratio