Highly Scaled InGaZnO Ferroelectric Field-Effect Transistors and Ternary Content-Addressable Memory

We demonstrate nonvolatile and area-efficient ternary content-addressable memories (TCAMs) featuring amorphous indium–gallium–zinc–oxide (a-IGZO) ferroelectric field-effect transistors (FeFETs) with excellent electrical characteristics. An extremely large sensing margin of the TCAM array is achieved due to the large current ON/OFF ratio ( $I_{ \mathrm{\scriptscriptstyle ON}}/I_{ \mathrm{\scriptscriptstyle OFF}})$ of the a-IGZO FeFETs. Our Hf_xZr $_{\text {1-x}}\text{O}$ ₂ (HZO)-based a-IGZO FeFETs have a metal–ferroelectric–metal–insulator–semiconductor (MFMIS) structure. By engineering the area ratio of the ferroelectric layer ( ${A}_{Fe}$ ) and the metal–oxide–semiconductor layer ( ${A}_{MOS}$ ), a large memory window (MW) of 2.9 V is realized. Reliability test results, including retention, endurance, and positive bias temperature instability, show long-term retention of more than ten years and high endurance of 10⁸ cycles. In addition, by scaling the channel length down to 40 nm, ON current of $77 ~\mu \text{A}/ \mu \text{m}$ ( ${V}_{\mathrm{GS}} - {V}_{\mathrm{TH}}$ = 5 V and ${V}_{\mathrm{DS}}$ = 2 V) and ${I}_{ \mathrm{\scriptscriptstyle ON}} / {I}_{ \mathrm{\scriptscriptstyle OFF}}$ of more than eight orders can be obtained for the ultrascaled a-IGZO FeFETs while maintaining an MW of 2.8 V.