Reduction Mechanism in the Dielectric Constant of Fluorine‐Doped Silicon Dioxide Film
Reduction Mechanism in the Dielectric Constant of Fluorine‐Doped Silicon Dioxide Film
复制标题
掺氟二氧化硅薄膜介电常数降低机理
DOI：
10.1149/1.1837850
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
H. Komiyama
中科院分区：
文献类型：
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作者：
Sangwoo Lim;Y. Shimogaki;Y. Nakano;K. Tada;H. Komiyama
超大规模集成电路中信号延迟的一种解决方案是使用低介电常数层间膜，例如F掺杂二氧化硅（SiO2）。通过在SiH 4 /N 0等离子体增强化学气相沉积中加入CF 4，我们获得了介电常数低至2.6的掺F SiO2薄膜。我们研究了这背后的介电常数减少的机制，通过估计由于每个极化分量（离子，电子和取向）使用电容-电压（C-V）测量，傅里叶变换红外光谱结合Kramers-Kronig关系，和光谱椭圆偏振法的常数。Kramers-Kronig计算结果表明，随着CF 4浓度的增加，离子极化率降低，而电子极化率几乎保持不变.然而，通过C-V测量获得的低介电常数不能完全由离子和电子极化的减少来解释，而可能是由于取向极化的减少。取向极化可能是由Si-OH键引起的，加入CF 4后取向极化主要减弱。因此，降低取向极化是降低掺氟SiO2薄膜介电常数的有效途径。
One solution to signal delay in very large-scale integrated circuits is to use a low dielectric constant interlayer film, such as F-doped silicon dioxide (SiO 2 ). By adding CF 4 to SiH 4 /N0 plasma-enhanced chemical vapor deposition, we obtained F-doped SiO2 films with a dielectric constant as low as 2.6. We studied the mechanism behind this decrease in the dielectric constant by estimating the constants due to each polarization component (ionic, electronic, and orientational) using capacitance-voltage (C-V) measurements, Fourier transform infrared spectroscopy spectra combined with the Kramers-Kronig relation, and spectroscopic ellipsometry. The Kramers-Kronig calculations showed that ionic polarization decreased with increasing CF 4 concentration, whereas the electronic polarization remained almost constant. However, the low dielectric constant obtained by the C-V measurements could not be completely explained by the reduction in ionic and electronic polarizations but probably resulted from a decrease in the orientational polarization. Orientational polarization may be caused by Si-OH bonds and is mainly decreased by adding CF 4 . Therefore, an effective way to reduce the dielectric constant in F-doped SiO 2 films is to reduce the orientational polarization.