Enhanced Performance of FeFET Gate Stack via Heterogeneously co-doped Ferroelectric HfO$_2$ Films

TL;DR

This study demonstrates that spatially controlled heterogenous co-doping of Zr and Al in HfO₂ films enhances FeFET performance by tuning phase evolution and improving electrical properties.

Contribution

It introduces a novel atomic layer deposition technique for spatially controlling dopant distribution to optimize ferroelectric properties in FeFETs.

Findings

Heterogeneous co-doping influences phase composition during annealing.

Spatial dopant arrangement affects remanent polarization.

Device endurance is significantly improved with optimized doping strategy.

Abstract

In this work, we explore the impact of spatially controlled Zr and Al heterogeneous co-doping in HfO$_2$ thin films tailored for metal-ferroelectric-insulator-semiconductor (MFIS) gate stacks of ferroelectric field effect transistors (FeFETs). By precisely modulating the vertical arrangement of Zr and Al dopants during atomic layer deposition, we introduce deliberate compositional gradients that affect crystallization dynamics during subsequent annealing. This strategy enables us to systematically tune the phase evolution and domain nucleation within the ferroelectric layer, directly influencing device reliability and performance. From a structural perspective, our findings demonstrate that the phase composition of annealed HfO$_2$ films in MFIS stacks is primarily determined by the spatial arrangement of dopants. From an electrical perspective, we observe significant enhancement of remanent polarization and endurance of the gate stacks through heterogeneous co-doping, depending on the spatial arrangement of dopants.