General Formula to Capture the Impact of Dummy Gates on Layout Dependent Effects Modeling of Multi-finger MOSFETs

This paper examines the impact of dummy gates on layout dependent effects (LDE) modeling of multi-finger MOSFETs. The LDE of the multi-finger MOSFETs without dummy gates is first measured and modeled, on top of that, a formula to calculate the LDE of each gate is derived based on linear decomposition. Then a general formula to model the LDE of devices with arbitrary number of dummy gates is derived. The formulas can be used in current mirror designs to determine the number of dummy gates needed for good matching as well as to model the LDEs for devices sharing the same active region. The formulas have been verified by measurement data of MOSFETs with either unpaired or paired gates.