Rost Marcel J, Jacobse Leon, Koper Marc T M
Huygens-Kamerlingh Onnes Laboratory, Leiden University, Niels Bohrweg 2, 2333 CA, Leiden, The Netherlands.
DESY NanoLab, Deutsches Elektronensynchrotron DESY, Notkestrasse 85, D-22607, Hamburg, Germany.
Nat Commun. 2019 Nov 20;10(1):5233. doi: 10.1038/s41467-019-13188-0.
In homoepitaxial crystal growth, four basic growth morphologies (idealized growth modes) have been established that describe the deposition of atoms on single crystal surfaces: step-flow, layer-by-layer, mound formation, and random/self-affine growth. Mound formation leads to nano-scale surface patterning. However, the formation of (nano)-islands, patterns, and roughness occurs also during ion bombardment, electrochemical etching and oxidation/reduction cycling. Here we show, in analogy to many particle/anti-particle formalisms in physics, the existence of the dualism between individual adatom and single vacancy growth modes. We predict that all standard adatom growth modes do exist also in their counter, vacancy version. For the particular case of mound formation, we derive the theoretical equations and show the inverse similarity of the solution. We furthermore treat simultaneous growth by adatoms and vacancies, and derive the analytical solution of the growth shape evolution of the mounds. Finally, we present an experimental verification, in which both adatom and vacancy mound formation are active. The theoretically predicted mound shape nicely fits the experimental observation.
在同质外延晶体生长中，已经确立了四种基本生长形态（理想化生长模式），用于描述原子在单晶表面的沉积：台阶流、逐层生长、丘状形成和随机/自仿射生长。丘状形成会导致纳米尺度的表面图案化。然而，（纳米）岛、图案和粗糙度的形成在离子轰击、电化学蚀刻以及氧化/还原循环过程中也会出现。在此，我们类似于物理学中的许多粒子/反粒子形式体系，展示了单个吸附原子和单空位生长模式之间二元性的存在。我们预测所有标准的吸附原子生长模式在其对应的空位模式中同样存在。对于丘状形成的特定情况，我们推导了理论方程并展示了解的反相似性。我们还处理了吸附原子和空位的同时生长，并推导了丘状生长形状演变的解析解。最后，我们给出了一个实验验证，其中吸附原子和空位丘状形成都很活跃。理论预测的丘状形状与实验观察结果非常吻合。
