"Ferroelectric Field Effect Transistors based on thin film HfO2 may be well-positioned to become the transistor of the future. Upon annealing, amorphous, atomic-layer-deposited HfO2 forms a monoclinic, non ferroelectric phase. To stabilize the orthorhombic, ferroelectric phase, precisely controlling the oxygen environment during deposition and/or doping with other materials are necessary. We propose that the key to control over crystallization lies in a better understanding of the amorphous phase. We will use TEM-based cryo-ePDF (pair distribution function) for structural characterization of a range of as-deposited films. We will investigate how deposition conditions such as temperature, impurities, thickness, and plasma treatment change the local atomic structure. Subsequently, as-deposited films will be annealed under neutral, oxidizing and reducing conditions. The long-range structure will be monitored through in situ XRD, while synchrotron-based grazing-incidence PDF will be used for short-and medium-range structural measurements. Finally, the layers will be measured electrically, both microscopically through cAFM/PFM and macroscopically though MIM structures to correlate the occurrence of the orthorhombic phase and grain size with ferroelectric properties. This project will result in process-structure-property relations for ferroelectric HfO2, and increase the understanding of this technologically highly relevant material."