First Demonstration of BEOL-Compatible Ferroelectric TCAM Featuring a-IGZO Fe-TFTs with Large Memory Window of 2.9 V, Scaled Channel Length of 40 nm, and High Endurance of 108 Cycles

For the first time, we report BEOL-compatible ferroelectric ternary content-addressable memory (TCAM) based on amorphous IGZO (a-IGZO) channel and HfZrO
2
(HZO) ferroelectric (Fe) layer, achieving a much larger sensing margin as compared with other TCAM technologies. Our a-IGZO ferroelectric thin-film transistors (Fe-TFTs) were realized using a low-temperature process of 400 °C and an MFMIS structure with the flexibility to engineer the area ratio of the ferroelectric layer (A
Fe
) and the metal-oxide-semiconductor layer (A
MOS
). The Fe-TFTs not only enjoy the largest memory window (MW) of 2.9 V for HZO-based Fe-TFTs with oxide semiconductor channels and high endurance of 10
⁸
cycles, but also a high conductance ratio and small cycle-to-cycle variation, leading to a high recognition accuracy (90.4%) of handwritten digits. Ultra-scaled devices with a channel length L
CH
of 40 nm exhibit enhanced drive current with MW as large as 2.8 V.