溶胶-凝胶法制备钡钕钛薄膜及其介电性能研究

Preparation and Dielectric Properties of Ba_4Nd_(9.33)Ti_(18)O_(54) Dielectric Thin Films Processed by Sol-Gel Technique

采用溶胶-凝胶法在Si(111)和Pt/Ti/SiO2/Si衬底上制备Ba4Nd9.33Ti18O54(BNT)介质薄膜,采用X线衍射仪(XRD)和扫描电子显微镜(SEM)研究了不同退火温度对薄膜结构和表面形貌的影响。结果表明当薄膜在950℃下退火2h后具有较好结晶质量的钨青铜结构,所得到的薄膜表面较为疏松;通过掺入质量分数为2%B2O3-2SiO2,可进一步将BNT薄膜的晶化温度降至900℃,且结构致密。介电性能测试表明,1 MHz频率下BNST薄膜的介电常数为45,介电损耗为1.1%,30V偏压下漏电流密度为4.13×10-6 A/cm2。

Ba4 Ndg. 3a Ti18 054 （BNT） thin films were obtained on Si and Pt/Ti/SiOz/Si substrates by Sol-Gel tech- nique. The effects of annealing temperature on crystallinity and morphological characteristic were investigated by X- ray diffraction （XRD） and scanning electron microscope （SEM）. The results showed that a porous and well crystal- lized thin film with a tungsten bronze structure was obtained by annealing these films at 950 ℃ for 2 h. After doped with 2% B2O3-2SiO2, the crystallization temperature was reduce to 900 ℃. The dielectric characteristics measurement showed that the dielectric constant and the dielectric loss of the BNT thin films were 45 and 1.10% at 1 MHz frequency, the leakage current density was 4.13 × 10-6 A/cm2 at bias of 30 V.