ITO衬底上LiTaO_3薄膜的制备与介电特性

PREPARATION AND DIELECTRIC PROPERTIES OF LiTaO_3 THIN FILM ON THE ITO SUBSTRATE

用溶胶凝胶法在ITO衬底上制备了钽酸锂(LiTaO3)薄膜,利用XRD、SEM和AFM对薄膜的晶向、表面形态等作了表征;研究了不同溶剂对LiTaO3溶胶稳定性的影响和不同退火条件对LiTaO3薄膜结晶的影响;利用Al/LiTaO3/ITO结构,测试了薄膜的介电系数和介电损耗.结果表明:每层薄膜都晶化退火比交替使用焦化、结晶退火能生长出质量更好的LiTaO3薄膜;频率1KHz时,介电损耗约0.4,相对介电系数约53.并讨论了介电损耗增大的原因.

LiTaO3 thin films were prepared on the ITO substrate by sol-gel methods. The performance parameters such as orientation, surface morphology, grain size and the thickness of LiTaO3 thin film were studied by XRD, SEM and AFM. The influence of different solvents on the stability of LiTaO3 sols and the influence of different annealing condition on the prepa- ration of LiTaO3 thin film were analyzed either. The relative dielectric coefficient and dielectric loss of the prepared LiTaO3 thin film were measured by using Al/LiTaO3/ITO structure electrode. The experimental results show that the quality of LiTaO3 thin film with every layer crystallized annealing is better than that with pyrolyzed and crystallized annealing alternately. The relative dielectric coefficient is about 53 and dielectric loss is about O. 4 when the measured frequency is 1 kHz. The reason of increaing the dielectric loss of LiTaO3 thin film has been discussed.