制备太阳能级多晶硅的工艺研究进展

太阳能级多晶硅的制备工艺分为物理法和化学法两大类。物理法包括造渣提纯硅法、利用热交换定向凝固提纯、利用电磁感应等离子技术提纯、CP法等，其中CP法生产的太阳能级多晶硅的纯度接近于化学法。但要生产纯度大于6N的多晶硅，仍需要采用化学法。目前常用的化学法有三氯氢硅氢还原法、硅烷热分解法、四氯化硅氢还原法等。三氯氢硅氢还原法又称改良西门子法，是化学法制备太阳能级多晶硅的主流工艺，不足之处是耗能大、污染严重、运行成本较高。

The Development of Process for Solar-Grade Polycrystalline Silicon Production

There are physical method and chemical method in preparation of solar-grade polycrystalline silicon.The former includes slag leaching,directional solidification purification by heat exchanging,plasma blowing by electromagnetic induction,CP and etc.The purity of solar-grade polycrystalline silicon obtained by CP method can nearly approach to that by chemical method.However,if the purity of solar-grade polycrystalline silicon is greater than 99.9999 %,the chemical method must be used.Generally,the chemical method included trichlorosilane hydrogen reduction method,silane thermal decomposition method and silicon tetrachloride hydrogen reduction method.Among these methods,the first one,which is also named modified Siemens process,is the popular process for silicon production,but with the disadvantages of high energy consumption,serious pollution,and high operation cost.