Geometry enhanced asymmetric rectifying tunneling diodes

In this article, the authors show that geometric asymmetry in the layout of tunnel diodes yields asymmetry in the current-voltage (I-V) relationships associated with these diodes. Asymmetry improves diode performance. This effect is demonstrated for polysilicon-SiO2-Ti/Au and for Ni-NiO-Ni tunneling structures. For a polysilicon-SiO2-Ti/Au asymmetric tunneling diode (ATD), sensitivity and I-V curvature improvements of 71% and 350% are achieved, respectively. For a Ni-NiO-Ni asymmetric diode, sensitivity and I-V curvature improvements of 15% and 39% are observed. The authors further demonstrate that this asymmetry enhances the microwave radiation detection sensitivity of these diodes at 900 MHz. Superior rectifying performance of a Ni ATD is observed due to smaller band-edge offsets in this material compared to that of a polysilicon ATD. The resulting structure can be further optimized using plasmonic field enhancement. (C) 2010 American Vacuum Society. [DOI:10.1116/1.3501350]