多晶硅膜的PECVD和LPCVD原位掺杂研究

Insitu Doping of Polysilicon Films by PECVD and LPCVD

对等离子增强化学气相淀积（ＰＥＣＶＤ）和低压化学气相淀积（ＬＰＣＶＤ）两种方法制备掺杂多晶硅膜进行了详细的实验研究，通过时两者进行比较，对淀积的动力学特性、淀积膜的结构、膜的电特性与工艺条件的关系等进行了分析讨论。结果表明，采用ＰＥＣＶＤ方法，多晶硅膜的生长速率几乎不受淀积温度和杂质掺入量的影响，且较采用ＬＰＣＶＤ方法的生长速率提高一个量级；膜的电导率随杂质的掺入可提高六个量级，且与淀积温度无关，其片内均匀性为±２％。

Two methods for preparing the doped polysilicon films ,the plasma-enhanced chemicalvapor deposition (PECVD)and the low-pressure chemical vapor deposition(LPCVD),havebeen studied experimentally.The dynamics of the deposition,the structures and the rela-tionship between the electrical properties of thedeposited films and the processing conditionsare discussed.It is shown that the growth rate of the polysilicon films deposited by thePECVD method is one order of magnitude higher than that by the LPCVD method.The con-ductivity of the films deposited by PECVD could be increased by six orders of magnitude asthe amount doped increases and it is independent of the deposition temperature. The across-the-wafer uniformity of the conductivity is found to be ±2%.