- Effect of temperature gradient on the diffusion layer thickness of impurities during directional solidification process
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- 论文类型： 期刊论文
- 发表时间： 2018-02-01
- 发表刊物： MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
- 收录刊物： SCIE、EI、Scopus
- 卷号： 74
- 页面范围： 102-108
- ISSN号： 1369-8001
- 关键字： Silicon ingot; Directional solidification; Temperature gradient; Diffusion layer thickness
- 摘要： The diffusion layer thickness of impurity during directional solidification process was evaluated under different temperature gradient conditions. The thickness of Fe, Cu, Ni and Ti in silicon ingot under 9.74 K/m were 6.19 mm, 4.92 mm, 4.61 mm and 8.70 mm, respectively; The thickness of Fe, Cu, Ni and Ti in silicon ingot under 28.49 K/m were reduced to 3.35 mm, 1.21 mm, 1.85 mm and 5.81, respectively. The diffusion layer thickness was reduced by the large temperature gradient to lead a low effective segregation coefficient. As a result, the impurity concentration of silicon ingot under 28.49 K/m was reduced to 0.94 ppmw. The strong vortex in the solid-liquid boundary interface was enhanced by the large temperature gradient, as the main transport mechanism to accelerate the diffuse of impurity atom in the diffusion layer, which effectively reduced the thickness of diffusion layer.
