Si(001)基片上反应射频磁控溅射ZnO薄膜的两步生长方法

利用反应射频磁控溅射技术，采用两步生长方法制备了ZnO薄膜，探讨了基片刻蚀时间和低温过渡层沉积时间对ZnO薄膜生长行为的影响.研究结果表明，低温ZnO过渡层的沉积时间所导致的薄膜表面形貌的变化与过渡层在Si(001)表面的覆盖度有关.当低温过渡层尚未完全覆盖基片表面时，ZnO薄膜的表面岛尺度较小、表面粗糙度较大，薄膜应力较大；当低温过渡层完全覆盖Si(001)基片后，ZnO薄膜的表面岛尺度较大、表面粗糙度较小，薄膜应力较小.基片刻蚀时间对薄膜表面形貌的影响与低温过渡层的成核密度有关.随着刻蚀时间的增加，ZnO薄膜的表面粗糙度逐渐下降，表面形貌自仿射结构的关联长度逐渐减小. 关键词： ZnO薄膜 反应射频磁控溅射 两步生长 形貌分析

Two-step growth of ZnO films deposited by reactive radio-frequency magnetron sputtering on Si(001) substrate

Using reactive radio-frequency magnetron sputtering, ZnO films have been deposited on Si(001) substrate with a two-step growth method. The first step: depositing a ZnO buffer layer at low temperature and annealing at 800 ℃, the second step: growing the ZnO at the temperature of 750 ℃. In this paper, we discuss the dependence of the ZnO film growth on the etching time of Si chips and the deposition time of the buffer layer. It is found that different deposition time of the buffer layer results in the difference in the morphology of ZnO films. The difference can be related to the coverage of the buffer layer. When the buffer layer does not cover the substrate, the ZnO film has small grains similar to the film without buffer layer and quite large roughness and internal stress. When the substrate is completely covered by the buffer layer, a ZnO film can be obtained with large-sized grains, smooth surface and low internal stress. The growth behavior of the ZnO films is also related to the etching time of Si chip. With the increase of etching time, both the roughness of the ZnO films and the correlation length of the self-affine morphology decrease.