传统 PECVD高品质氢化非晶硅的淀积率

The Deposition Rate of the High-quality Hydrogenated Amorphous Silicon Prepared by the Conventional PECVD Process

根据 Winer模型 ,联合 Winer模型和 Street的氢化学势理论 ,分别研究了传统 PECVD( CPECVD)高品质氢化非晶硅 ( HQ a-Si:H)的淀积率上限 rdup和淀积率 rd 与 a-Si:H缺陷密度 ND 的关系。得到的结论是 :( 1 )rdup=1 .6nm/s(目前实验上 rd 已接近 1 .0 nm/s)。( 2 )对每一优化淀积温度 ( Ts=2 0 0～ 30 0°C) ,存在一相应的优化淀积率 rdop,当 rd<rdop时 ,rd 增加 ,ND减小 (解释了 Tsuda etal的实验曲线的左边 )。还讨论了在大淀积率下( 0 .5 nm/s<rd<rdup)制备 HQ a-Si:H时避免粉末形成的可能方法。结果显示 :适当功率密度 Pd/Si H4 流速率 fr和 (或 )适当的 Si H4 气压 Pr/fr匹配是至关重要的。

Following Winer model combining Street's hydrogen chemical potential, we have investigated respectively the upper limited of deposition rate, r_(dup), of the high quality a-Si:H prepared by the conventoinal PECVD (CPECVD) as well as the relation between the CPECVD a-Si:H defect density, N_D, and its deposition rate, r_d. The resulting conclusions are:(1)r_(dup)=1.6 nm/s. At present, r_(dup) have approached experimentally to 1.0 nm/s.(2)For each optimal deposition temperature (200～300(°C)), there is a correspondent optimal deposition rate,r_(dop). On the condition of r_d<r_(dop), when r_dincrease, N_Ddecrease. This is just the left property of Tsuda et al's experimental curve (250(°C)).At last, we discuss the polymer reaction and powder formation under the high r_d (>0.5 nm/s). It is shown that, in roder to avoid these disadvantages, the suitable matching of the power density P_d/SiH_4flow rate and/or SiH_4pressure P_r/f_rare the decisive importance factor.