Ferroelectric FET (FeFET) is a non-volatile memory transistor that uses a ferroelectric material in the gate stack to store data as polarization states — combining logic and memory in a single device with near-zero standby power, nanosecond switching, and CMOS-compatible integration using doped HfO2.

How FeFET Works

• Ferroelectric Gate: The gate dielectric contains a thin ferroelectric layer (typically doped HfO2).
• Polarization States: Applying a voltage pulse switches the ferroelectric polarization direction (up or down).
• Threshold Voltage Shift: Different polarization states shift the transistor's Vt — creating two distinct logic states.
• Polarization UP → Low Vt → High read current → Logic "1".
• Polarization DOWN → High Vt → Low read current → Logic "0".
• Non-Volatile: Polarization is retained without power — data persists.

Why HfO2 Ferroelectrics Changed Everything

• Traditional ferroelectrics (PZT, SBT) were CMOS-incompatible — contained Pb, required thick films.
• Discovery (2011): Doped HfO2 (Si-doped, Zr-doped) is ferroelectric at 5–10 nm thickness.
• HfO2 is already used in HKMG process — minimal integration disruption.
• Scalable to advanced nodes (sub-10 nm films).

FeFET vs. Other Non-Volatile Memories

Applications

• Embedded Non-Volatile Memory: Replace eFlash in MCUs — faster, smaller, lower power.
• Compute-in-Memory: FeFET arrays perform multiply-accumulate operations — analog AI acceleration.
• Neuromorphic Computing: Analog weight storage with multi-level polarization.

FeFET is a leading candidate for next-generation embedded non-volatile memory — the discovery that HfO2 is ferroelectric at nanoscale thickness unlocked a path to memory-logic integration that is fully compatible with existing CMOS manufacturing.