Epitaxial Structure Simulation Study of In0.53Ga0.47As/AlAs Double-Barrier Resonant Tunnelling Diodes

We present an epitaxial structure simulation study of In
0.53
Ga
0.47
As/AlAs double-barrier resonant tunnelling diodes (RTD) employing Atlas TCAD quantum transport simulation software developed by SILVACO, which is based on the non-equilibrium Green’s function (NEGF) formalism. We analyse how epitaxial layers design impacts the heterostructure static current density-voltage (JV) characteristic, including barriers, quantum well (QW), and lightly-doped spacers, as well as the employment of a high-bandgap emitter region. Our analysis shows that, while barriers and QW thicknesses have a strong impact on the current operation of the RTD device, accurate asymmetric spacers design can trade-off between the voltage span and relative position of its negative differential resistance (NDR) region, while a high-bandgap alloy at the emitter side lowers the RTD bias point. This work will guide in optimising the RTD epitaxial structure in order to maximise its RF power performance at low-terahertz frequencies (~ 100−300 GHz).