F. Beall1, A. Rimal1, O. Seidel1, Y. Mei1, A. D. McDonald3, I. Parmaksiz5,1 V. A. Chirayath1, J. Asaadi1, D. Braga2, J. B. R. Battat4
DC Cryogenic Modeling of Open-Source SkyWater 130 nm MOSFETs at 77K Using BSIM4
arXiv:2604.21625v1 [cond-mat.mes-hall] 23 Apr 2026
1 The University of Texas at Arlington, Physics Department, Arlington, TX 76019, USA
2 Fermi National Accelerator Laboratory, Microelectronics Department, Batavia, IL 60510, USA
3 Instrumentation Frontier Scientific, Arlington, TX 76019, USA
4 Wellesley College, Physics and Astronomy Department, Wellesley, MA 02481, USA
5 Rice University, Physics Department, Houston, TX 77005, USA
Abstract: Cryogenic applications in high-energy physics (HEP) demand reliable, low-power CMOS electronics capable of operating at liquid nitrogen temperatures (77K). The open-source SkyWater 130nm (SKY130) CMOS process has previously been shown to operate at temperatures as low as 4K making it a promising candidate for HEP applications. In this work, we characterize and model SKY130 low-threshold voltage transistors at 77K, which is a temperature commonly used in modeling applications for liquid argon detectors. DC characteristic measurements were performed at both room temperature and liquid nitrogen temperature. We created a cryogenic modeling approach to produce a SPICE-compatible, isothermal BSIM4-based model for select transistor sizes at 77K. The resulting model agrees with data at 77K with an average error on the order of 20% (relative RMS) and shows no dependence on drain voltage. Due to the open-source nature of SKY130, we have made our models publicly available on Github. We hope this work will continue the trend for democratizing circuit design at cryogenic temperatures in high-energy physics by enabling open access to accurate cryogenic CMOS device models at 77K.
Fig: Hardware setup used for I-V measurements: (a) Schematic of the I-V measurement
system (b) Wirebonded SKY130 chip mounted on PCB
Acknowledgments: The authors would like to thank various engineers in the microelectronics department at FNAL for their guidance and assistance on this project: Albert Dyer for help operating the cryo-cooler, and Louis Dal Monte and Pamela Klabbers for PCB design. The authors would also like to extend gratitude to Andy Pender from Synopsys for assistance with the modeling software, Mystic™. This material is also based upon work supported by U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award Number DE-SC0022296 and DE-SC00253485 as well as support from the University of Texas at Arlington’s Center for Advanced Detector Technologies.
