基片对SrTiO_3薄膜结构与介电性能的影响

Effect of Substrate on the Microstructure and Dielectric Properties of SrTiO_3 Thin Films

对比研究了MgO和LaAlO3(LAO)单晶基片上采用脉冲激光法生长的SrTiO3(STO)薄膜的微观结构和介电性能。通过XRD,AFM和制备叉指电容测量的方法研究发现,在MgO基片上生长高质量(00L)织构STO薄膜需要较高的生长温度;LAO基片上的STO薄膜更加平整;而MgO上的STO薄膜具有更高的零偏压介电常数和更强的非线性介电性质。

SrTiO3 （STO） thin films were deposited onto MgO and LaAIO3 （LAO） single crystal substrate via pulsed laser deposition. The effect of these two substrates on the microstructure and dielectric properties of STO thin films were investigated by XRD, AFM and measuring the interdigital capacitor on the thin films. Higher growth temperature is needed to get high quality STO thin films on MgO than on LAO substrate, while smoother films are grown on LAO. The capacitance measurements show that STO thin films on MgO substrate have larger zero-bias dielectric constant and stronger nonlinear dielectric property.