Crystallization process of high-k gate dielectrics studied by surface X-ray diffraction

We have studied the crystallization process of HfO2 and HfAlOx films using grazing incidence X-ray diffraction (GIXRD) with synchrotron radiation. The HfO2 and HfAlOx films were grown by atomic layer deposition (ALD) on a chemical SiO2 interfacial layer. X-ray diffraction (XRD) patterns of the HfO2 film as-deposited contain not only the monoclinic phase but also the orthorhombic or tetragonal phase. With increasing annealing temperature, the orthorhombic or tetragonal phase decreases and disappears. The HfAlOx film crystallized after annealing at 900 °C. The crystallographic phase was the cubic phase of CaF2 type.