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本文采用磁控溅射法,衬底温度500℃下在硅衬底上分别制备具有Ge填埋层的a-Si/Ge薄膜和a-Si薄膜,并进行后续退火,采用Raman光谱、X射线衍射、原子力显微镜及场发射扫描电镜等对所制薄膜样品进行结构表征.结果表明,Ge有诱导非晶硅晶化的作用,并得出以下重要结论:衬底温度为500℃时生长的a-Si/Ge薄膜,经600℃退火5 h Ge诱导非晶硅薄膜的晶化率为44%,在相同的退火时间下退火温度提高到700℃,晶化率达54%.相同条件下,无Ge填埋层的a-Si薄膜经800℃退火5 h薄膜实现晶化,晶化率为46%.通过Ge填埋层诱导晶化可使在相同的条件下生长的非晶硅晶薄膜的晶化温度降低约200℃.Ge诱导晶化多晶Si薄膜在Si(200)方向具有高度择优取向,且在此方向对应的晶粒尺寸约为76 nm.通过Ge诱导晶化制备多晶Si薄膜有望成为制备高质量多晶Si薄膜的一条有效途径.
In this paper, a-Si / Ge film and a-Si film with Ge buried layer were prepared on the silicon substrate by magnetron sputtering at a substrate temperature of 500 ℃ and annealed. The Raman spectra, X-ray Diffraction, atomic force microscopy and field emission scanning electron microscopy were used to characterize the prepared thin films.The results show that Ge has the effect of inducing amorphous silicon crystallization, and the following important conclusions are drawn: The growth of a at substrate temperature of 500 ℃ -Si / Ge thin films, the crystallization rate of amorphous silicon films induced by annealing at 600 ℃ for 5 h was 44%, and the annealing temperature increased to 700 ℃ and the crystallization rate reached 54% at the same annealing time.Under the same conditions, The a-Si film without Ge buried layer was crystallized by annealing at 800 ℃ for 5 h, and the crystallization rate was 46% .Inducing crystallization through Ge buried layer can make the amorphous silicon thin film grown under the same conditions Decreases by about 200 ° C.Ge-induced polycrystalline Si films have a highly preferred orientation in the Si (200) direction, and the corresponding grain size in this direction is about 76 nm. Polycrystalline Si thin film is expected to be an effective way to prepare high quality polycrystalline Si thin film.