Spectroscopic ellipsometry characterization of the optical properties and thermal stability of Zr O2 films made by ion-beam assisted deposition

The optical properties, interface structure, and thermal stability of the Zr O2 films grown on Si(100) were investigated in detail. A 2 nm thick interfacial layer (IL) is formed at the Zr O2 -Si interface for the as-grown Zr O2. The optical constants of Zr O2 films and IL correspond to amorphous- Zr O2 and amorphous- Si O2, respectively. The oxidation and IL growth at 900 °C, as a function of annealing time, exhibit a two-step behavior with a slow and a fast growth-rate zones. The transition from a zone of slow to fast rate is attributed to structurally modified Zr O2 facilitating the faster oxygen transport to the Zr O2 Si interface.