Hot Carrier Degradation in MOSFETs at Cryogenic Temperatures Down to 4.2 K
Yuanke Zhang, Jun Xu, Tengteng Lu, Yujing Zhang, Chao Luo, Guo‐Ping Guo
Abstract
Wide attention has been focused on cryogenic CMOS (cryo-CMOS) operation because of its promising improvement of devices’ and circuits’ performance and wide application prospects. However, hot carrier degradation (HCD) limits the long-term reliability of cryo-CMOS. This article investigates HCD in 0.18 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> bulk CMOS at cryogenic temperature down to 4.2 K. Particularly, the relationship between HCD and the current overshoot phenomenon and the influence of substrate bias on HCD are discussed. Besides, we predict the lifetime of the device at 77 K and 4.2 K. It is concluded that cryogenic NMOS cannot reach the ten years’ commercial standard lifetime at standard <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$V_{DD}$ </tex-math></inline-formula> . And it is predicted that the reliability requirements can be reached when <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$V_{DD} \leq 1.768$ </tex-math></inline-formula> V and 1.734 V at 77 K and 4.2 K, respectively. Differently, the lifetime of PMOS is long enough even at low temperatures.