Control of Chemical Bonding and Surface Modification of Nitrogen-Implanted Glassy Carbon by Doping of Different Kinds of Elements

1.在这项工作中，我的特点是硅掺杂的氮化碳层形成的N注入，以调查的影响，硅掺杂的化学键合的氮化物层。结果表明，Si浓度为5- 8at. %是无定形的，并且主要具有sp^2键合的碳结构和少量的C N键。XPS谱中化学位移的检查表明，预注入Si的GC中的氮化物层中存在局部C=N-Si（C_nN_<3-n>）排列。氮化碳层中C=N-Si（C_nN_）结构的形成<3-n>增加了N原子可能的键合位置的数量，并可能导致注入N原子的更高的饱和水平，氮化层中的N浓度从26 at. %至35。%。此外，氮化物层中的Si原子在N注入过程中起到了阻止氧掺入的作用，尽管其机制尚不清楚.结果表明，氢掺杂（0.30at. %）是获得表面光滑的注氮GC的有效方法。注入氮离子时，部分掺杂氢原子被释放，但同时发生氢的掺入。因此，N注入层中的氢浓度超过20原子%。%。XPS和拉曼分析表明，掺杂和未掺杂的石墨中氮原子的化学键合非常相似，但含氮石墨层的尺寸不同。石墨层的较小尺寸可松弛在抛光划痕处引入的应变，这可保持表面光滑。

1. In this work, I have characterized Si doped carbon nitride layer formed by N implantation to investigate effects of Si doping on the chemical bonding in the nitride layer. It is found that the carbon nitride layer with Si concentration of 5-8 at. % is amorphous and has predominantly an sp^2 bonded carbon structure with a small amount of C≡N bonds. The examination of chemical shifts in XPS spectra suggests the existence of local C=N-Si(C_nN_<3-n>) arrangements in the nitride layer in Si-preimplanted GC. The formation of the C=N-Si(C_nN_<3-n>) structures in the carbon nitride layer increases the number of possible bonding sites for N atoms and may result in the higher saturation level for the implanted N atoms ; the N concentration in the nitride layer increased from 26 at. % to 35 at. % by the Si-preimplantation. In addition, Si atoms in the nitride layer play a role in the prevention of oxygen incorporation during N implantation, although the mechanism is not yet known.2. It was demonstrated that the hydrogen doping (〜30 at. %) was an effective method to obtain a smooth surface of N-implanted GC. A part of the doped hydrogen atoms is released by N implantation, but hydrogen incorporation occurs simultaneously. Consequently, concentration of hydrogen in the N-implanted layer exceeds 20 at. % at any N implantation doses. XPS and Raman analysis reveals that chemical bonding in the N-implanted layer for the D-doped GC is quite similar to that for the undoped, GC, but the size of graphitic layers containing N atoms is different. The smaller size of the graphitic layers can relax the strain introduced at polishing scratches, which may maintain the surface smooth.