Synthesis of diamond films and nanotips through graphite etching
Synthesis of diamond films and nanotips through graphite etching
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DOI：
10.1016/j.carbon.2004.10.047
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发表时间：
2005
期刊：
影响因子：
10.9
通讯作者：
Qiaoqin Yang;W. Chen;C. Xiao;R. Sammynaiken;A. Hirose
中科院分区：
文献类型：
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作者：
Qiaoqin Yang;W. Chen;C. Xiao;R. Sammynaiken;A. Hirose
基于石墨氢蚀刻的热丝 CVD 工艺已被开发用于合成金刚石薄膜和纳米尖端。将石墨片放置在靠近基底的位置，并且在沉积过程中仅供应氢气。该工艺不需要碳氢化合物原料气。在无放电或偏压的情况下，在 P 型（100）取向硅片上以高生长速率合成了高质量金刚石薄膜。在类似的沉积条件下，金刚石的生长速率比使用甲烷和氢气的气体混合物（1vol.% 甲烷）的传统热丝化学气相沉积的生长速率高出大约五倍。在此过程中合成的金刚石薄膜表现出较小的微晶并且包含较少量的非金刚石碳相。当基底支架在直流辉光放电中施加负偏压时，在 CVD 金刚石涂层硅基底上合成了具有不同取向角的排列良好的金刚石纳米尖端。在距样品边缘足够远的位置处生长的纳米尖端垂直对齐，而样品边缘周围的纳米尖端则倾斜并远离样品中心。纳米尖端的排列方向似乎是由样品表面上局部电场线的方向决定的。
A hot filament CVD process based on hydrogen etching of graphite has been developed to synthesize diamond films and nanotips. The graphite sheet was placed close to the substrate and only hydrogen was supplied during deposition. No hydrocarbon feed gases are required for this process. High quality diamond films were synthesized with high growth rate on P-type (100)-oriented silicon wafers without discharge or bias. The diamond growth rate is approximately five times higher than that through conventional hot filament chemical vapor deposition using a gas mixture of methane and hydrogen (1vol.% methane) under similar deposition conditions. The diamond films synthesized in this process exhibit smaller crystallites and contain smaller amount of non-diamond carbon phases. Synthesis of well-aligned diamond nanotips with various orientation angles was achieved on the CVD diamond-coated Si substrate when the substrate holder was negatively biased in a DC glow discharge. The nanotips grown at locations far enough from the sample edges are aligned vertically, while those around the sample edges are tilted and point away from the sample center. The alignment orientation of the nanotips appears to be determined by the direction of the local electric field lines on the sample surfaces.