椭圆偏振光谱实时在线监测与离线分析微晶硅薄膜的生长

采用甚高频等离子体增强化学气相沉积技术高速沉积了有无籽晶层两个系列微晶硅薄膜,通过椭圆偏振光谱、拉曼光谱和XRD对薄膜进行了分析,发现采用籽晶层后,在薄膜沉积初期有促进晶化的作用;由于籽晶层减少了薄膜的诱导成核时间,提高了薄膜的沉积速率,对比了实时在线和离线椭圆偏振光谱两种测量状态对分析微晶硅薄膜的影响,研究发现,当薄膜较薄时,实时在线测量得到的薄膜厚度小于离线下的数值;当薄膜较厚时,两种测量条件下得到的薄膜厚度差异较小;实时在线条件下得到的表面粗糙度要大于离线条件下得到的数值，这是由于薄膜暴露在大气中后表面有硅氧化物生成,对表面有平滑作用.

Real time and ex situ spectroscopic ellipsometry analysis microcrystalline silicon thin films growth

Microcrystalline silicon thin films with and without a seed layer were deposited using very high frequency plasma enhanced chemical vapor deposition method at a high growth rate. The influence of the seed-layer method on the film growth and structure were investigated using spectroscopic ellipsometry(SE), Raman spectrum and X-ray diffraction. The results show that the seed-layer can not only increase the growth rate, but also promote crystalline nucleation at the initial growth stage. The deposition processes were monitored by real time spectroscopic ellipsometry(RTSE). The film was also measured by ex situ SE in the air. The differences between the RTSE and ex situ SE have been studied in testsing the microcrystalline silicon thin films. Results show that for the thin films the total thickness obtained by RTSE is smaller than that by ex situ SE, while for the thick films the measured total thicknesses by two methods are almost the same. However, the surface roughness thickness detected by RTSE is larger than that by ex situ SE. The reason for this is due to oxidation of the thin film exposed to the air which smoothed the film surface.