Suppression of Oxygen Impurity Incorporation into Silicon Films Prepared from Surface-Wave Excited H2/SiH4 Plasma
Suppression of Oxygen Impurity Incorporation into Silicon Films Prepared from Surface-Wave Excited H2/SiH4 Plasma
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DOI：
10.1143/jjap.43.7696
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发表时间：
2004-11
影响因子：
1.5
通讯作者：
S. Somiya;H. Toyoda;Y. Hotta;H. Sugai
中科院分区：
文献类型：
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作者：
S. Somiya;H. Toyoda;Y. Hotta;H. Sugai
利用2.45 GHz、2kW氢气高度稀释的SiH4中的表面波等离子体(SWP)沉积多晶硅薄膜。当使用石英窗口作为微波注入放电时，在沉积的薄膜中观察到高达∼1.5%的氧杂质水平。质谱分析表明，氧的来源是水，即高密度等离子体中许多氢自由基对石英窗口(SiO_2)的化学侵蚀产物。用Al_2O_3(Al_2O_3)窗口代替石英窗口后，氧杂质含量显著降低，薄膜的晶粒度增大。
Surface-wave plasma (SWP) in SiH4 highly diluted with H2 at 2.45 GHz and 2 kW is applied to the deposition of polycrystalline silicon thin films. When a quartz window is used as a microwave injection for discharge, an oxygen impurity level of up to ∼1.5% is observed in the deposited films. Mass spectrometry reveals that the origin of oxygen is water, i.e., the chemical erosion product of the quartz window (SiO2) caused by many hydrogen radicals in high-density plasma. By replacing the quartz window with an alumina (Al2O3) window, oxygen impurity level is markedly reduced, along with the increase in the grain size of films.