Impact of Thickness Dependent Ferroelectric and Interface Charge Variation on Device-to-Device Variation in Ferroelectric FET

In this work, the film thickness-dependent threshold voltage <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(VTH)</tex> variation is investigated theoretically through statistical Monte Carlo simulation. An improved VTH variation is found in the 6 nm <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Hf0.5Zr0.5O₂</tex> (HZO) gate insulator under the coupling effect of ferroelectric parameters and interface charge density fluctuations, in comparison to thicker HZO films. The increase in trap density significantly deteriorates the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">VTH</tex> variation, which can be mitigated by the enlarged charge response in the thin film. This work provides a guideline for variation performance improvement in building reliable ultra-scale integrated circuits.