Impact of vacancies and impurities on ferroelectricity in PVD- and ALD-grown HfO₂ films

We investigate the emerging chemical states of TiN/HfO2/TiN capacitors and focus especially on identification vacancies impurities in ferroelectric HfO2 layers, which are produced either by physical vapor deposition (PVD) or atomic layer (ALD). Depending specific growth conditions, we identify different mechanisms oxygen vacancy formation. Corresponding spectral features consistently observed for all HfO2- TiN-related core levels hard x-ray photoelectron spectroscopy (HAXPES). In ALD-grown samples, find signatures electronic interaction between nitrogen impurities. By linking HAXPES results to electric field cycling experiments capacitors, discuss possible formation stabilization phase directly related PVD ALD conditions.