[paper] Characterization and Modeling of SOI LBJTs at 4K

Yuanke Zhang, Yuefeng Chen, Yifang Zhang, Jun Xu, Chao Luo, and Guoping Guo

Characterization and Modeling of Silicon-on-Insulator 

Lateral Bipolar Junction Transistors at Liquid Helium Temperature

IEEE TED Vol. XX, No. XX, preprint arXiv:2309.09257 (2023).

University of Science and Technology of China (USTC), Hefei 230026, Anhui, China

CAS Key Lab ofQuantum Information, Hefei 230026, Anhui, China.

Abstract: Conventional silicon bipolars are not suitable for low-temperature operation due to the deterioration of current gain (β). In this paper, we characterize lateral bipolar junction transistors (LBJTs) fabricated on silicon-on insulator (SOI) wafers down to liquid helium temperature (4 K). The positive SOI substrate bias could greatly increase the collector current and have a negligible effect on the base current, which significantly alleviates β degradation at low temperatures. We present a physical-based compact LBJT model for 4 K simulation, in which the collector current (IC) consists of the tunneling current and the additional current component near the buried oxide (BOX)/silicon interface caused by the substrate modulation effect. This model is able to fit the Gummel characteristics of LBJTs very well and has promising applications in amplifier circuits simulation for silicon-based qubits signals.

Fig: IC (solid lines) and IB (dash lines) versus VBE of LBJT at different temperatures 

under (a) VBOX = 0 V; (b) VBOX = 12 V, VCE = 1 V.

Acknowledgement: The device fabrication was done by Prof. Zhen Zhang’s group in the Angstrom Microstructure Laboratory (MSL) at Uppsala University. Dr. Qitao Hu, Dr. Si Chen, Prof. Zhen Zhang are acknowledged for the device design and fabrication, and the technical staff of MSL are acknowledged for their process support.