Insights into interlayer tunnel FET performance improvement: Lessons learned from graphene hexagonal boron nitride heterostructures

We have explored ITFETs with varying thickness of graphene conduction layers. We have found that due to the increase in the DOS for thicker graphene, the resonance peaks are enhanced. However, due to the increase in the number of sub-bands and smaller spacing between the sub-bands for multi-layer graphene, especially Bernalstacked odd number of layer graphene with Dirac cone bands, the resonance peaks are more closely spaced together and result in either subdued NDR characteristics or no NDR at all. Although an even number of layer graphene offers fewer resonance peaks, we found that for thin interlayer hBN, bandgap opening causes the peaks to broaden.