衬底效应对LiTaO_3薄膜制备的影响

Substrate Effects on Preparation of LiTaO_3 Thin Films

用溶胶凝胶法在N型硅、P型硅、石英、铂、镍衬底上制备了钽酸锂(LiTaO3)薄膜,用XRD和SEM对钽酸锂薄膜性能参数进行了表征;发现掺杂少量环氧树脂能提高钽酸锂薄膜的均匀性,改善薄膜与衬底的粘附性;研究了衬底效应与薄膜厚度的关系,薄膜厚度超过0.2μm,Ni衬底的XRD峰值强度几乎不再出现,说明衬底对薄膜初始结晶取向有重要影响;利用不同衬底上生长钽酸锂薄膜,XRD研究结果表明:N型硅、P型硅、石英衬底上只能制备多晶钽酸锂薄膜,铂衬底上制备的钽酸锂薄膜在(012)晶向有强大的择优取向性,镍衬底上制备的钽酸锂薄膜有更好的C轴择优取向性,C轴择优取向系数可达0.082。

The sol-gel derived LiTaO3 thin films were prepared on the substrates of N-type Si （100）, P-type Si （111）, Quartz, Pt/TiO2/SiO2/Si （100）, and Nickel, respectively. The properties of LiTaO3 thin films were measured using XRD and SEM. Experimental results show the doped epoxy resin can improve the uniformity of LiTaO3 thin films and the adhesiveness between LiTaO3 thin films and the substrates. The relation between thin film thickness and substrate effect was studied. The intensive peak of XRD of the Nickel substrate does not appear again when the thickness of LiTaO3 thin film excesses 0.2 μm, and the result shows that the substrates have important influence on the initial crystallization of the LiTaO3 thin film. The XRD results also show only polycrystalline LiTaO3 thin films can be prepared on N-type Si （100）, P-type Si （111）, and Quartz substrate. The LiTaO3 thin films deposited on the Pt/TiO2/SiO2/Si （100） substrate has a strong （012） plane preferred orientation. The LiTaO3 thin films deposited on the Nickel substrate has a perfect C-axis preferred orientation with a large C-axis orientation degree factor of 0.082.