太阳能多晶硅片表面线状缺陷的形貌特征及形成原因

MORPHOLOGY AND FORMATION MECHANISM OF LINEAR DEFECTS ON SOLAR-ENERGY MULTICRYSTALLINE SILICON WAFERS

研究了定向凝固生长的多晶硅线切割过程中在多晶硅片表面产生的线状缺陷的形貌特征及其形成机制。分别采用扫描电子显微技术和X射线衍射技术对多晶硅片线切割引起的线状缺陷的形貌特征及夹杂物进行研究,结果表明:多晶硅片表面线切割过程中形成的线状缺陷是因SiC夹杂物的存在而引起的,当切割钢丝与多晶硅中的SiC夹杂物相遇时,在拉力作用下钢丝爬越SiC夹杂物,同时在SiC夹杂物的表面发生研磨现象,在多晶硅片表面留下线状缺陷。

Multicrystalline silicon （mc-Si） for solar cells is mainly grown by the directional solidification method. The wire sawing-induced linear defects on multicrystalline silicon wafers and their formation mechanism were investigated. Scanning electron microscopy and X-ray diffraction techniques were used to study the morphological characteristics of these linear defects and the related foreign inclusions. It was shown that the linear defects are caused by the presence of SiC inclusions which are climbed over by the steel wire. In the meantime, the surfaces of these SiC inclusions are also ground during the wire sawing process. The Si3 N4 inclusions are not responsible for the formation of linear defects.