等离子体辅助铝诱导纳米硅制备多晶硅的研究

Growth of Polycrystalline Si Layers by Plasma-Enhanced Annealing and Al-Induced Crystallization of Nanocrystalline Si Films

以超白玻璃为衬底,利用热丝化学气相沉积和磁控溅射法制备了Glass/nc-Si/Al叠层结构,置入管式退火炉中进行等离子体辅助退火。样品在氢等离子体氛围下进行了400,425和450℃不同温度,5 h的诱导退火,用光学显微镜和拉曼光谱对样品进行了性能表征。结果表明随着诱导温度升高,样品的Si(111)择优取向越来越显著;晶粒尺寸不断增大,在450℃诱导温度下获得了最大晶粒尺寸约500μm的连续性多晶硅薄膜,且该温度下薄膜晶化率达97%;薄膜的结晶质量也随着温度的升高而不断提高。样品经450℃诱导后的载流子浓度p为5.8×1017cm-3,薄膜霍尔迁移率μH为74 cm2/Vs。还从氢等离子体钝化的角度分析了等离子体环境下铝诱导纳米硅的机理。

The nano-crystalline Si films,grown by hot wire chemical vapor deposition on the glass substrates,were oxidized in air for 48 h,and coated with magnetron sputtered Al films.After plasma-induced annealing for 5 h in H＋ atmosphere,the glass/nc-Si/Al layers were characterized with X-ray diffraction,Raman spectroscopy and optical microscope.The results show that the annealing temperature strongly affects the re-crystallization and microstructures of the polycrystalline Si layers.For example,as the temperature rose up,Si grain size increased with a more pronounced（111）preferential growth orientation.At 450℃,the poly-Si layer has the largest Si grain size of 500 μm,a crystalline volume fraction of 97%,a carrier density,p,of 5.8×1017 cm-3,and a Hall mobility,μH,of 74 cm2/Vs.The possible mechanism responsible for the Al-induced Si re-crystallization was briefly discussed.