Structure and optical properties of HfO2 thin films on silicon after rapid thermal annealing

✍ Scribed by Tingting Tan; Zhengtang Liu; Hongcheng Lu; Wenting Liu; Hao Tian

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 231 KB
• Volume: 32
• Category: Article
• ISSN: 0925-3467
• DOI: 10.1016/j.optmat.2009.10.003

✦ Synopsis

HfO 2 thin films have been deposited on Si substrate by radio frequency reactive magnetron sputtering. The optical and structural properties of HfO 2 thin films in relation to rapid thermal annealing (RTA) temperatures are investigated by spectroscopic ellipsometry (SE), X-ray diffraction (XRD) and UV Raman spectrum. XRD and Raman measurements show that the as-deposited films are mainly amorphous and a transition to a crystalline phase occurs after RTA. Based on a parameterized Tauc-Lorentz dispersion model, the optical constants of the as-deposited and annealed films are systematically extracted. With increased annealing temperature, the refractive index n and the extinction coefficient k are observed to increase. The changes of the complex dielectric functions with annealing temperature are also discussed.