Manufacturability and electrical characteristics of Si/SiGe interband tunnelling diodes

We investigated the DC-characteristics and the scalability of Si/SiGe interband tunnelling diodes(ITDs) as a function of the layer structure and device geometry. The Si spacer thicknesses X_{p and XN between the intrinsic SiGe layer and the p-and n-δ-doped layers were varied between 0 and 2 nm. We obtained a maximum peak current density of 16 κA/cm² and a peak-to-valley current ratio of 2.7 (with a device area of 45 μm² ) for a structure with Xp = 0 nm and XN = 1 nm. Performed simulations of electrical characteristics of the ITDs show a reasonable agreement with the experimental data. The investigation of the scalability of ITDs shows that the current density in the diode is inversely proportional to the cathode area. A numerical model describing the lTD scaling is proposed.}