Ferroelectricity in HfO2 thin films as a function of Zr doping

摘要

We have studied the effect of Zr doping, from 0% to 100%, on the ferroelectric properties of HfO. Amorphous HfZrO on TiN and Si substrates is deposited using atomic layer deposition (ALD) and then annealed in a rapid thermal processing (RTP) tool while capped by 20 nm of sputtered TiN. Based on our experiments, Zr doping of up to 50% results in ferroelectricity in polycrystalline HfZrO, whereas Zr doping of 70% and above shows antiferroelectricity. Our results show how the properties of ferroelectric HfO can be engineered through changing doping and annealing conditions, thereby demonstrating the flexibility of ferroelectric HfO for integration in future memory and logic devices.