Abstract—At design time, engineers want to simulate circuits at -55 ℃.However, the value temperature of some device models provided by PDKs (process design kit) is as low as -40 ℃. Simulating circuits at -55 ℃ with models will cause a certain deviation. In this paper, we propose the method to extend MOSFET (metal oxide semiconductor field effect transistor) model from -40 ℃ to -55 ℃ based on evolutionary strategy. IDS at threshold voltages (Vth) and maximum IDS of linear and saturation regions were acquired by simulating the MOSFET with a certain size under the PDK’s useful temperature range. Then, we fitted data and obtained threshold voltages and maximum IDS values corresponding to -55 ℃. We used the evolutionary strategy algorithm to adjust some device model parameters so that simulated IDS values are close to the respective fitting values. The fitness is the sum of the relative error of four values and becomes about 1/6 of the original value for the 1.8 V NMOS (N-Channel Metal-Oxide-Semiconductor) device. This method proposes a new idea to extend model temperature, which is beneficial to engineers’ work.
Index Terms—MOSFET, device model, optimization, evolutionary strategy
Tengteng Lu, Dong Li, and Xiao Mo are with the Department of Research, Anhui Siliepoch Technology co., Ltd, Hefei, China.
Jinzhong Sun is with the 38 Institutes of China Electronics Technology Group, Hefei, China.
Correspondence: luteng@mail.ustc.edu.cn
Cite: Tengteng Lu, Jinzhong Sun, Dong Li and Xiao Mo, "Device Model Extending from -40℃ to -55℃ Based on Evolutionary Strategy," International Journal of Modeling and Optimization. vol. 13, no. 1, pp. 13-18, 2023.
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