衬底温度对ZnO薄膜生长过程及微观结构的影响研究

以醋酸锌水溶液为前驱体,采用改进的超声喷雾热解法在Si(100)衬底上沉积ZnO薄膜,以X射线衍射(XRD)、扫描电镜(SEM)等手段分析所得ZnO薄膜的晶体结构和微观形貌,着重考察了衬底温度对ZnO薄膜生长过程及微观结构的影响.结果表明,在衬底温度为500℃下所得ZnO薄膜表面均匀光滑,属六方纤锌矿结构,且沿c轴择优生长,晶粒尺寸的为40～50nm;衬底温度对ZnO薄膜生长过程影响显著,随衬底温度的升高,薄膜生长速率存在一极限值,且ZnO薄膜的c轴取向趋势增强,晶粒尺寸得到细化.

Effect of Substrate Temperature on the Deposition Process and Microstructure of ZnO Films Grown by Ultrasonic Spray Pyrolysis Method

ZnO thin films were grown on Si (100) substrate by the modified ultrasonic spray pyrolysis (USP). X-ray diffeaction (XRD) and scanning electron microscopy (SEM) were employed to analyze the crystalline and microscopic structure of the films. The effect of the substrate temperature on the growth mechanism and the microstructure of ZnO films were studied. Results show that the as-deposited ZnO films are dense, smooth and homogeneous with uniform spherical crystallites, consistent with the hexagonal wurtzite polycrystalline structure. The preferential orientation of (002) is for all deposited films. The minimum crystallite size of ZnO films under the optimal growth condition is 40 to 50 nm. The temperature of the substrate has significant effects on the deposition process. With the increase of the temperature of the substrate, there lies a maximum deposition rate of ZnO films, which can be interpreted by differeat growing mechanism, and the preferential orientation along c axis is augmented in a marked degree and the crystalline grain size is refined as well.