  Intimate integration of memory devices with logic transistors is a frontier
challenge in computer hardware. This integration is essential for augmenting
computational power concurrently with enhanced energy efficiency in big-data
applications such as artificial intelligence. Despite decades of efforts,
reliable, compact, energy efficient and scalable memory devices are elusive.
Ferroelectric Field Effect Transistors (FE-FETs) are a promising candidate but
their scalability and performance in a back-end-of-line (BEOL) process remain
unattained. Here, we present scalable BEOL compatible FE-FETs using
two-dimensional (2D) MoS2 channel and AlScN ferroelectric dielectric. We have
fabricated a large array of FE-FETs with memory windows larger than 7.8 V,
ON/OFF ratios of greater than 10^7, and ON current density greater than 250
uA/um, all at ~80 nm channel lengths. Our devices show stable retention up to
20000 secs and endurance up to 20000 cycles in addition to 4-bit pulse
programmable memory features thereby opening a path towards scalable 3D
hetero-integration of 2D semiconductor memory with Si CMOS logic.
