基片温度对基于Bi1.5Zn1.0Nb1.5O7栅绝缘层的ZnO基TFT性能的影响

在不同基片温度(RT、300、400、500和600℃)下,采用射频磁控溅射法制备了ZnO薄膜和BZN薄膜.研究表明,所制备的BZN薄膜拥有非晶态结构,ZnO薄膜具有c轴择优取向,在基片温度为500℃时,获得低的漏电流(10-7 A/cm2),比RT时的漏电流(10-4 A/cm2)低三个数量级.将所制备的ZnO薄膜和BZN薄膜分别作为ZnO-TFT的有源层和栅绝缘层,研究表明,在基片温度为500℃时,提高了器件性能,所取得的亚阈值摆幅(470 mV/dec.)是RT时的亚阈值摆幅(1 271 mV/dec.)的三分之一;界面态密度(3.21×1012 cm-2)是RT时的界面态密度(1.48×1013 cm-2)的五分之一.

Effects of Substrate Temperature on ZnO-TFT Based on Bi1.5 Zn1.0 Nb1.5O7 Insulating Layer

ZnO and BZN thin films were deposited by RF magnetron sputtering under different substrate temperature from RT to 600 ℃.It can be seen that BZN thin films are amorphous structure,and ZnO thin films has the c-axis preferred orientation.At 500 ℃,the leakage current density of BZN thin film is approximately three order magnitude lower than that of BZN thin film at RT.The sub-threshold awing (470 mV/dec.) of ZnO-TFT with BZN thin films as gate insulator and ZnO thin films as active layer is approximately three times lower than that of device (1 271 mV/dec.) at RT,and the surface state density (3.21 × 1012 cm-2) of ZnOTFT is approximately five times lower than that of device (1.48 × 1013 cm 2) at RT.