AN ATOMISTIC MODEL FOR STEPPED DIAMOND GROWTH
AN ATOMISTIC MODEL FOR STEPPED DIAMOND GROWTH
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DOI：
10.1038/372535a0
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发表时间：
1994-12-08
期刊：
影响因子：
64.8
通讯作者：
WEINER, B
中科院分区：
文献类型：
--
作者：
FRENKLACH, M;SKOKOV, S;WEINER, B
许多晶体材料的生长是通过台阶在表面上的横向扩展发生的（1-3）。阶梯式结构也是化学气相沉积（CVDM）生长的金刚石的特征（4-10）。原子在表面上的扩散通常被认为是导致金属阶阶生长的原因，但人们认为（11-14），原子之间更强的键合应该阻止这种机制在金刚石的情况下起作用。然而，最近的实验（15）表明，表面扩散可以在金刚石生长过程中发生。我们最近在理论上（16）表明，在氢存在下生长的金刚石{100}平面上的桥接亚甲基（CH2）基团可以以相当于表面扩散的方式迁移。在这里，我们证明了这一理论图景可以发展成一个原子模型来解释金刚石的阶梯式生长。阶梯式模式可以理解为从气态前体形成表面结合的物质，然后通过一系列涉及共价键断裂和形成的表面化学反应进行迁移。
The growth of many crystalline materials occurs through lateral propagation of steps over the surface(1-3). A stepped texture is also characteristic of diamond grown by chemical vapour deposition (CVDM)(4-10). Diffusion of atoms on the surface is usually held responsible for the stepped growth of metals, but it has been thought(11-14) that the stronger bonding of adatoms should prevent this mechanism from operating in the case of diamond. Recent experiments(15) have, however, indicated that surface diffusion can take place during diamond growth. We have recently shown theoretically(16) that bridging methylene (CH2) groups on the {100} plane of diamond growing in the presence of hydrogen can migrate in a manner equivalent to surface diffusion. Here we show that this theoretical picture can be developed into an atomistic model that accounts for stepped growth of diamond. The stepped pattern can be understood in terms of the formation of surface-bound species from the gaseous precursors, followed by their migration by means of a series of surface chemical reactions involving covalent bond breaking and formation.