Effect of Boron Doping on the Wear Behavior of the Growth and Nucleation Surfaces of Micro- and Nanocrystalline Diamond Films
Effect of Boron Doping on the Wear Behavior of the Growth and Nucleation Surfaces of Micro- and Nanocrystalline Diamond Films
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DOI：
10.1021/acsami.6b08083
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发表时间：
2016-10-05
影响因子：
9.5
通讯作者：
Vandervorst, Wilfried
中科院分区：
文献类型：
--
作者：
Buijnsters, Josephus G.;Tsigkourakos, Menelaos;Vandervorst, Wilfried
在微电子机械系统(MEMS)领域，掺杂B的金刚石已经成为最终的应用材料，这对高耐磨和导电的金刚石薄膜和微结构提出了更高的要求。尽管人们对未掺杂金刚石的摩擦学性能进行了广泛的研究，但到目前为止，人们对高掺硼金刚石的磨损性能的了解非常有限。因此，本工作对高掺硼金刚石的磨损行为进行了全面的研究。往复滑动试验是对不同B掺杂水平和厚度的微晶和纳米晶金刚石(MCD，NCD)薄膜进行的。我们证明了不同金刚石薄膜的磨损率与B的掺杂量呈线性关系。具体地说，当温度为0.6和2.8at时，NCD薄膜的磨损率提高了3倍。%B-掺杂水平。这种磨损率的增加可以与高度掺B的NCD薄膜的硬度和弹性模数下降50%有关，通过纳米压痕测量确定。此外，我们还发现细晶金刚石膜更容易磨损。特别是，颗粒尺寸较小3倍但B掺杂水平相近的NCd薄膜表现出双倍的磨损率，表明颗粒尺寸对金刚石薄膜的磨损行为起着至关重要的作用。另一方面，MCD薄膜由于其较大的颗粒和较低的B掺杂水平而是最耐磨的薄膜。我们提出了一个涉及表面平坦化和机械力化学驱动的非晶化的磨损行为的图解来描述掺B金刚石薄膜的磨损机制。最后，首次研究了NCD薄膜成核面的磨损行为。具体地说，形核表面由于其较高的晶界线密度，比生长表面更容易受到磨损。
B-doped diamond has become the ultimate material for applications in the field of microelectromechanical systems (MEMS), which require both highly wear resistant and electrically conductive diamond films and microstructures. Despite the extensive research of the tribological properties of undoped diamond, to date there is very limited knowledge of the wear properties of highly B-doped diamond. Therefore, in this work a comprehensive investigation of the wear behavior of highly B-doped diamond is presented. Reciprocating sliding tests are performed on micro- and nanocrystalline diamond (MCD, NCD) films with varying B-doping levels and thicknesses. We demonstrate a linear dependency of the wear rate of the different diamond films with the B-doping level. Specifically, the wear rate increases by a factor of 3 between NCD films with 0.6 and 2.8 at. % B-doping levels. This increase in the wear rate can be linked to a 50% decrease in both hardness and elastic modulus of the highly B-doped NCD films, as determined by nanoindentation measurements. Moreover, we show that fine-grained diamond films are more prone to wear. Particularly, NCD films with a 3x smaller grain size but similar B-doping levels exhibit a double wear rate, indicating the crucial role of the grain size on the diamond film wear behavior. On the other hand, MCD films are the most wear-resistant films due to their larger grains and lower B-doping levels. We propose a graphical scheme of the wear behavior which involves planarization and mechanochemically driven amorphization of the surface to describe the wear mechanism of B-doped diamond films. Finally, the wear behavior of the nucleation surface of NCD films is investigated for the first time. In particular, the nucleation surface is shown to be susceptible to higher wear compared to the growth surface due to its higher grain boundary line density.