射频磁控溅射沉积高质量ZnO薄膜的工艺研究

在室温下利用射频磁控溅射法在硅(100)基片上制备ZnO薄膜,利用X射线衍射(XRD)和扫描电子显微镜(SEM)对其结晶性能进行分析。研究了制备条件对薄膜沉积速率的影响。分析了薄膜沉积速率对薄膜结晶状况的影响及源气体中的氧气和氩气的流量比对薄膜结晶状况的影响。研究结果表明,薄膜的生长速率强烈依赖于射频功率和工作气压,薄膜的结晶性能强烈依赖于薄膜的沉积速率和反应气体中氧气和氩气的流量比。制备高结晶质量的ZnO薄膜的最佳工艺参数为靶到衬底的距离为4cm,输入功率为250W,源气体中氩气和氧气的流量比n(Ar)∶n(O2)为5∶20,溅射工作气压为2Pa。在最佳工艺条件下所制备的薄膜表面平整致密,接近单晶,在可见光区的透射率高达90%。     

用于高亮LED的Si键合研究

在Si和外延层之间使用一层薄金属层作为高效反射镜的所谓"镜面衬底",不但有助于提高芯片的出光效率,同时把键合温度降低到300℃以下。利用Au/In合金的方法,来实现用于高亮LED的Si片与AlGaInP四元外延片的键合。实验表明,在温度为250℃时,利用Au/In作为焊料,Si片与AlGaInP四元外延片可以实现比较好的键合,键合面可以达到60%。通过研磨减薄、X-ray测试和扫描电镜(SEM)测试得出键合面的界面特性,通过能谱分析得出键合面的物质分别为AuIn2和AuIn,实验测试得出此时Au的原子数占33.31%,In的原子数占36.64%。     

Effects of Annealing on Luminescence of ZnO Films Deposited on Si Substrates by RF Magnetron Sputtering

Effects of growth ambience, annealing ambience and temperature on the photoluminescence (PL) emission properties of ZnO films deposited on Si (100) substrates by RF magnetron sputtering have been investigated. After annealing, the crystal quality of ZnO films was markedly improved, and the intensity of UV emission peak increased obviously. By varying the flow rate ratio of O2/Ar, annealing atmosphere in oxygen-deficient or oxygen-rich ambience and heating temperature during deposition, the evolution of peak intensities and positions for blue and green emission is formed. This is attributed to the deposition and annealing parameters that control the desorptions and adsorptions of oxygen atoms on the films, and leads to the changes of concentrations of Zinc and oxygen vacancies in the films.