Two step evolution strategy for device motif BSIM model parameter extraction

Abstract

The modeling and simulation of semiconductor devices is a difficult and computationally intensive task. However the expense of fabrication and testing means that accurate modeling and simulation are crucial to the continued progress of the industry. To create these models and then perform the simulations requires parameters from accurate physical models to be obtained and then more abstract models created that can perform more complex circuit simulations. Device models (motifs) are created as a mitigation technique for improvement the circuit performance and as technology advances to help with the effects of transistor variability. In order to explore the characteristics of new device motifs on circuit designs, obtaining accurate and reliable device models becomes the first problem for designers. In this paper a Two Step Evolution Strategy (2SES) is proposed for device parameter model extraction. The proposed 2SES approach automatically extracts a set of parameters with respect to a specified device model. Compared with conventional mathematical extraction approach, 2SES is an efficient and accurate method to solve the parameter extraction problem and simultaneously addresses the fact of the mathematical extraction having the complexity of Multi-objective optimization. Compared with single step ES extract result, it is shown that the two-step ES extraction process continues improving generations by adjusting the optimisation parameters. Finally, an application of a new device motif on circuit design is given at end of the paper and compared against a standard device.