高速微晶硅薄膜沉积功率利用效率的测量与优化

Power Efficiency Enhancement in High-Rate Deposition ofMicrocrystalline Silicon Coatings

为了实现低成本微晶硅薄膜的高速沉积,需要尽可能的优化工艺参数,特别是提高功率利用效率对于降低生产成本,以及提高工艺稳定性都具有重要的意义。文中对射频等离子体增强化学气相沉积系统的各部分功率消耗进行了测量与分析,发现实际用于辉光放电的功率利用率仅为10%以下;腔室的寄生电阻自身消耗功率占30%左右,且寄生电抗分布情况对匹配器的功率消耗影响较大。通过对系统硬件的改造,降低了寄生电抗的影响,显著地提高了功率耦合效率,在高反应气压条件下的功率利用率达到60%以上。

The power consumption in the growth of large area silicon coatings, a film material for solar cells, at a high deposition rate by plasma enhanced chemical vapor deposition（PECVD）was measured and analyzed, to save energy and reduce production cost. The measured and calculated results show that the discharge power accounts for less than 10% of the total power,provided by the power supply, whereas about 30% power was dissipated by the strayed impedance in the reactor. Besides, the distribution of the strayed impedance inversely affects the power consumption of the RF match- box. A novel type of electrode was optimized, redesigned, constructed and installed in the reactor. With the newly - devel- oped electrode, the power efficiency was enhanced from less than 10% to higher than 60% at a higher pressure of the re- active gases because the influence of the strayed impedance in the PECVD reactor was considerably minimized.