Thermally Stable, BEOL-Configured MEMS-Based One-Time Programmable (OTP) Memory for Cryogenic Embedded Application

In this letter, we demonstrate a MEMS-based one-time programmable(OTP) memory cell integrated into the back-end-of-line (BEOL) layers of a TSMC <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.35~\mu $</tex-math> </inline-formula>m 2P4M CMOS process, designed for operation down to 4 K. This novel design eliminates the need for fusing currents, relying instead on surface-adhesion phenomena for programming. The memory cells operate with a low read voltage of 0.05 V and read current of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$80~\mu $</tex-math> </inline-formula>A, ensuring low power consumption and minimal heat generation (~2.8 K). The read resistance ranges from 0.5 to 5.5k<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Omega $</tex-math> </inline-formula> in the logic ‘1’ (ON-state) and ~2.4 T<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Omega $</tex-math> </inline-formula> in the logic ‘0’ (OFF-state), achieving an on-off ratio in the order of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{9}$</tex-math> </inline-formula>. The switching energy is limited to 0.5–2.6 pJ, with a demonstrated memory retention of 4 hours at 300, 120, and 4 K. These features make it highly suitable for storing micro-operations permanently in cryogenic embedded applications.[2025-0028]