Modeling of width-quantization-induced variations in logic FinFETs for 22nm and beyond

The nature of FinFET devices prohibits continuous width scaling and introduces a digitization of device width. As a consequence, devices are comprised of arrays of Fins ranging from one (SRAM) to a few tens of Fins. This introduces an intrinsic variation in the device that is absent in conventional planar devices. To build a reliable circuit, model parameters have to be provided that take account of the correct scaling behavior with increasing number of Fins for the composite device. For the first time we address in this paper how a composite Fin device can be modeled correctly. The statistical drive current and leakage current distribution are accurately modeled using the proposed methodology. We show that the DIBL vs. SS relationship for the composite device is an easily accessible indicator for the intrinsic variations observed in a composite device.