Total Ionizing Dose Impact on 22-nm FD-SOI Ring Oscillator Current and Frequency

Abstract

Total ionizing dose (TID) has a significant effect on silicon-on-insulator (SOI) circuits, manifesting primarily as a front-gate threshold voltage ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$V_{t}$ </tex-math></inline-formula> ) shift. This article presents data on ring oscillator (RO) responses of 22-nm fully depleted (FD-SOI) thin oxide (core logic) devices to gamma-ray doses above 1 Mrad(Si). We show large current and frequency TID response differences between ROs comprised of different logic gates. Moreover, the extensive experimental results presented here show that these responses vary significantly with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$V_{t}$ </tex-math></inline-formula> and well type. The measurements show that depending on the expected dose and transistor <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$V_{t}$ </tex-math></inline-formula> used, TID-induced standby current ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$I_{\mathrm {SB}}$ </tex-math></inline-formula> ) increases may have a substantial impact on overall power in spaceborne integrated circuits (ICs) using this fabrication process. The TID impact on digital circuit timing margins is also discussed.