Effect of La Spatial Uniformity on Ferroelectric Properties of HfO2 Films Deposited by Atomic Layer Deposition Method

In this study, the effect of supercycle scheme for La‐doping in HfO 2 films by atomic layer deposition (ALD) on their ferroelectric properties is investigated along with the variation of La distribution in HfO 2 films. La is doped into HfO 2 films by two ALD supercycle methods: metal‐oxidant‐dopant‐oxide (MODO) and metal‐dopant‐oxidant (MDO). Secondary ion mass spectrometry analys is shows that the MDO supercycle method results in a uniform distribution of La in the depth direction, while the MODO supercycle method results in depth‐dependent segregation of La in the HfO 2 film. For similar La concentrations, HfO 2 films doped with La by the MDO supercycle show a higher percentage of orthorhombic phase with higher oxygen vacancy concentrations than films by the MODO supercycle. For 3% La, the HfO 2 film by MDO shows a remanent polarization (2 P r ) of ≈31 μC cm −2 at ± 4 MV cm −1 , which is twice as large as the remanent polarization of 15 μC cm −2 for the HfO 2 film by MODO. In addition, the La‐doped HfO 2 film by MDO with a larger fraction of orthorhombic phase shows a smaller wake‐up effect than the La‐doped HfO 2 film by MODO.