Abstract a-C:H and a-C:H:Si:O films with two different Si/O co-doping contents had been deposited using a PECVD system by the mixture of C2H2 and HMDSO gas. The structure evolution of as-deposited and annealed films had been characterized by the Raman spectroscopy, XPS and FTIR. A progressive increase of sp2 carbon sites and a reduction of sp3 with the increase of the annealing temperature were expected. However, the Si/O co-doping was found to be able to reduce the graphitization degree of the annealed films. After annealing at 400 °C, the decrease rate of sp3 fraction of a-C:H film was 14.2%, while the a-C:H:Si:O (0.93 at.% Si) film was 8.16% and the a-C:H:Si:O (3.62 at.% Si) film was 6.8%. To understand the mechanism on the improved thermal stability by Si/O co-doping, the structure and residual stress of the a-C:H and a-C:H:Si:O films were analyzed. The results revealed that silicon atoms were incorporated into the carbon network by substituting carbon atoms of the films, which had also been characterized contributed to produce the C Si sp3 bonds stabilized by the oxygen. Residual stress characterization also demonstrated that, the residual stress of the a-C:H:Si:O films was greatly reduced compared with that of the a-C:H films. Therefore, the fraction of the highly strained C C sp3 bonds, which were more likely to break at elevated temperature, was reduced in the a-C:H:Si:O films. This kind of structure evolution endowed the a-C:H:Si:O films higher hardness and adhesion at high temperature.

中文翻译：

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Si/O掺杂氢化类金刚石碳膜增强热稳定性的结构与机理研究

摘要 使用 PECVD 系统通过 C2H2 和 HMDSO 气体的混合物沉积了具有两种不同 Si/O 共掺杂含量的 aC:H 和 aC:H:Si:O 薄膜。沉积和退火薄膜的结构演变已通过拉曼光谱、XPS 和 FTIR 进行表征。随着退火温度的升高，sp2 碳位点逐渐增加，sp3 逐渐减少。然而，发现Si/O共掺杂能够降低退火膜的石墨化程度。在 400 °C 下退火后，aC:H 薄膜的 sp3 分数降低率为 14.2%，而 aC:H:Si:O（0.93 at.% Si）薄膜为 8.16%，aC:H:Si： O (3.62 at.% Si) 膜为 6.8%。为了理解 Si/O 共掺杂提高热稳定性的机制，aC:H 和 aC:H:Si 的结构和残余应力：分析O膜。结果表明，硅原子通过取代薄膜的碳原子而结合到碳网络中，这也有助于产生由氧稳定的 C Si sp3 键。残余应力表征还表明，与 aC:H 薄膜相比，aC:H:Si:O 薄膜的残余应力大大降低。因此，在 aC:H:Si:O 薄膜中，在高温下更容易断裂的高应变 CC sp3 键的比例减少了。这种结构演化赋予了 aC:H:Si:O 薄膜更高的硬度和高温附着力。这也被表征有助于产生由氧稳定的 C Si sp3 键。残余应力表征还表明，与 aC:H 薄膜相比，aC:H:Si:O 薄膜的残余应力大大降低。因此，在 aC:H:Si:O 薄膜中，在高温下更容易断裂的高应变 CC sp3 键的比例减少了。这种结构演化赋予了 aC:H:Si:O 薄膜更高的硬度和高温附着力。这也被表征有助于产生由氧稳定的 C Si sp3 键。残余应力表征还表明，与 aC:H 薄膜相比，aC:H:Si:O 薄膜的残余应力大大降低。因此，在 aC:H:Si:O 薄膜中，高应变 CC sp3 键的比例在升高的温度下更容易断裂。这种结构演化赋予了 aC:H:Si:O 薄膜更高的硬度和高温附着力。在 aC:H:Si:O 薄膜中减少。这种结构演化赋予了 aC:H:Si:O 薄膜更高的硬度和高温附着力。在 aC:H:Si:O 薄膜中减少。这种结构演化赋予了 aC:H:Si:O 薄膜更高的硬度和高温附着力。