Molybdenum interlayers for nucleation enhancement in diamond CVD growth.
Molybdenum interlayers for nucleation enhancement in diamond CVD growth.
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DOI：
10.1166/jnn.2010.1392
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发表时间：
2010-04
影响因子：
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通讯作者：
J. G. Buijnsters;L. Vázquez;R. Galindo;J. J. ter Meulen-J.
中科院分区：
文献类型：
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作者：
J. G. Buijnsters;L. Vázquez;R. Galindo;J. J. ter Meulen-J.
采用热灯丝化学气相沉积法在硅衬底上制备了50 nm厚的Mo中间层，研究了Mo中间层对微晶金刚石（MCD）和纳米金刚石（NCD）薄膜成核的促进作用。MCD和NCD膜分别使用1%和2%的甲烷浓度沉积。Mo成核层的存在使得能够形成具有降低的表面粗糙度（对于750-nm厚的层，rms粗糙度约为40 nm）并且由于NCD膜形成的早期阶段中的上级成核密度和表面覆盖而具有显著更少的界面空隙的更均匀的NCD膜。在MCD膜生长的初始阶段，成核密度增加了一个数量级相比，未涂覆的硅。结果，也可以生产具有较小表面晶粒尺寸的薄得多的MCD膜，并因此降低表面粗糙度。Mo成核层的存在不仅导致NCD和MCD膜的结构优化，而且还允许在相对低的衬底温度（约575摄氏度）下的快速成核和膜生长动力学，这与不耐受高衬底温度的衬底材料的涂覆有关。
The use of a 50-nm thick Mo interlayer on silicon substrates for the nucleation enhancement of microcrystalline diamond (MCD) and nanocrystalline diamond (NCD) films synthesized by hot filament chemical vapour deposition was studied. The MCD and NCD films were deposited using methane concentrations of 1% and 2%, respectively. The presence of a Mo nucleation layer enabled the formation of more uniform NCD films with reduced surface roughness (rms roughness approximately 40 nm for a 750-nm thick layer) and with significantly less interfacial voids due to the superior nucleation densities and surface coverage in the early stages of NCD film formation. During the initial stages of MCD film growth, the nucleation density increased by one order of magnitude as compared to uncoated silicon. As a result, much thinner MCD films with smaller surface grain sizes and, thus, reduced surface roughness could be produced as well. The presence of a Mo nucleation layer not only leads to a structural optimization of NCD and MCD films but also allows fast nucleation and film growth kinetics at relatively low substrate temperatures (approximately 575 degrees C), relevant for the coating of substrate materials that do not withstand high substrate temperatures.