Analysis of junction leakage in advanced germanium P+/n junctions

Abstract

We analysed heavily doped p+/n junctions in germanium, and found that the halos in this work provide a tradeoff between transistor channel control and junction leakage. Temperature-dependent leakage measurements show that either trap-assisted tunneling (TAT) or band-to-band-tunneling (BTBT) are the dominant leakage mechanisms for junctions with halos, (junction doping above ~ 1018 cm-3). Further, perimeter leakage data at/near room temperature for these junctions are consistent with the Hurckx model for TAT. At lower doping levels (no Halo), leakages are significantly lower and correspond to a shockley-read-hall (SRH) mechanism at/near room temperature and a standard diffusion current mechanism for temperatures above ~ 75degC.