Annealing Temperature Dependent Microstructure and Optical Properties of HfxTi1-xO2 Thin Films

作者：Zhang, J. W.; He, G.^*; Gao, J.; Chen, X. S.; Chen, X. F.; Deng, B.; Liu, Y. M.; Zhang, M.; Lv, J. G.; Sun, Z. Q.

来源：Science of Advanced Materials, 2014, 6(9): 1979-1985.

DOI：10.1166/sam.2014.2124

• Hafnium Titanate
• Spectroscopic Ellipsometry
• Optical Properties
• Cauchy-Urbach Model

High-permittivity hafnium titanate (HfxTi1-xO2) films have been deposited on Si substrates by RF sputtering and subjected to rapid thermal annealing at various temperatures in air. Post annealing temperature dependent microstructure and optical properties of the HfxTi1-xO2 films were investigated by X-ray diffraction (XRD), spectroscopic ellipsometry (SE), atomic force microscope (AFM), and ultraviolet-visible spectroscope (UV-Vis). Analysis from XRD reveals that the as-deposited films are amorphous as well as those samples annealed at lower annealing temperature. However, with increasing annealing temperature, polycrystalline structure with highly (-111) preferential orientation appears. AFM results show that annealing leads to the increase in surface roughness. Combined with UV-Vis and SE measurements, red shift in band gap has been observed as a function of annealing temperature. Additionally, increase in optical constant has been confirmed by SE based on Cauchy-Urbach model.

• 出版日期2014-9
• 单位中国科学院; 中国科学院上海技术物理研究所; 安徽理工大学; 合肥师范学院; 安徽大学