石英坩埚内高纯隔离层在高效多晶硅铸锭中的应用

Application of High Purity Barrier Layer in the Silica Crucible for the Casting of High-performance Multi-crystalline Silicon Ingot

多晶硅铸锭过程中,石英坩埚侧壁中的杂质通过固相扩散进入并残留在多晶硅锭的边部,形成多晶硅锭边部的低少子寿命区(边部红区)。本文通过在坩埚侧壁上制作三种不同成分的高纯隔离层来阻挡坩埚侧壁中的杂质向硅锭中的扩散,以降低硅锭中的边部红区比例。结果表明采用掺钡高纯隔离层可以使硅锭中的边部红区显著变窄,基本消除硅方中的边部红区。

In the directional solidification growth of multi-crystalline silicon （mc-Si） ingot, the impurities diffuse from the silica crucible walls into the silicon ingot through the solid phase diffusion, which forms the low minority carrier lifetime region （red-zone） at the edge of the silicon ingot. In this paper, three kinds of high purity barrier layers of different ingredinet were coated onto the inner walls of the silica crucible to prevent the diffusion of impurities from the crucible into the silicon ingot, and to decrease the proportion of the red-zone near the edge of the ingot. The results showed that the high purity barrier layer with barium doping was effective in decreasing the width of the red-zone in the silicon ingot and could eliminate the red zone in the silicon bricks.