Capacitorless MEMS-Based Temporary Memory (CMTM) With Extended Refresh Interval

Microelectromechanical system (MEMS)-based mechanical memories are a promising solution in edge devices that require the usage of charge-free storage. Herein this article, we present a capacitorless MEMS-based temporary memory (CMTM) cell offering charge-free storage. This CMTM cell is capable of both memory access and bit storage thereby eliminating the need for multiple elements in a single-bit cell. The implementation of the CMTM cell relies on the structural engineering of the ratio <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\xi $ </tex-math></inline-formula> between the surface adhesion force of the contact electrodes (source and drain) and the restoring force supplied by the actuating MEMS structure. Three different memory cells having <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\xi $ </tex-math></inline-formula> values of 0.9, 0.7, and 0.6 are designed, fabricated, and tested for harnessing <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\xi $ </tex-math></inline-formula> property for temporary storage. Fabricated CMOS-compatible memory cell having <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\xi =0.9$ </tex-math></inline-formula> showcases a noteworthy refresh interval (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\tau _{\text {hold}}$ </tex-math></inline-formula>) of 100 ms. The retention characteristics of the programmed CMTM cell for one second are also demonstrated.