连续离子层吸附与反应法(SILAR)生长ZnO多晶薄膜的研究

采用连续离子层吸附与反应法(SILAR),以锌氨络离子([Zn(NH₃)₄]²⁺)为前驱体溶液,在玻璃衬底上沉积了ZnO薄膜,以XRD和SEM等手段分析了薄膜的晶体结构和表面、断面形貌,考察了空气气氛下的退火过程对ZnO薄膜晶体结构与微观形貌的影响,并初步探讨了以SILAR方法沉积ZnO薄膜的机理.结果表明,经200次SILAR沉积循环,所得ZnO薄膜为红锌矿结构的多晶薄膜,沿<002>方向择优生长;薄膜表面致密、光滑均匀,厚度约800nm.退火处理使ZnO薄膜氧缺位减少,晶粒沿c轴取向增强;随退火温度升高,锌间隙原子增加;500℃退火时,ZnO薄膜发生再结晶.减小前驱体溶液的[NH₃·H₂O]/[Zn²⁺]比率可提高ZnO薄膜生长速率.

Deposition of Polycrystalline ZnO Thin Films by Successive Ionic Layer Adsorption and Reaction Process (SILAR)

ZnO thin films were grown on glass substrates by a relatively new and simple chemical deposition method, successive ionic layer adsorption and reaction (SILAR), with the precursor of zinc-ammonia complex ([Zn(NH₃)₄]²⁺. XRD and SEM were applied to analyze the crystalline structure and the morphology. The effects of annealing process in air on the crystalline structure and the morphology of ZnO films were discussed. Further, the growing mechanism of ZnO films by SILAR technique was probed. Results show that, the obtained ZnO films after 200 deposition cycles are the zincite structure with the orientation of <002>. The as-deposited films are dense, smooth and uniform, with the film thickness of 800nm. The annealing process in air results in the decrease in oxygen vacancy of ZnO films and the increase in the degree of orientation along c-axis. The amount of interstitial zinc also increases with the augment of the annealing temperature. The re-crystallization resulted from the air annealing at 500℃ affects the micro structure and morphology of ZnO films significantly. The decrease in the ratio of NH₃·H₂O to Zn²⁺ in precursor will improve the growth rate of ZnO films.