In this report we present a novel strategy in selective epitaxial growth on top of Si pillars, which results in a tessellated Ge film, composed by self-aligned micron-sized crystals in a maskless process. Modelling by rate equations the morphology evolution of fully facetted crystal profiles is extensively outlined, showing an excellent prediction of the peculiar role played by flux shielding among microcrystals, in the case of dense array configuration. Crack formation and substrate bending, caused by the mismatch in thermal expansion coefficients, are eliminated by the mechanical decoupling among individual microcrystals, which are also shown to be dislocation- and strain-free. The method has been also tested for Si_1−xGe_x alloys, with compositions ranging from pure silicon to pure germanium. There are ample reasons to believe that this approach could be extended to other material combinations and substrate orientations, actually providing a technology platform for several device applications.

在本报告中，我们提出了一种在Si柱上进行选择性外延生长的新策略，该策略可产生由无对准工艺中的自对准微米级晶体组成的镶嵌Ge膜。通过速率方程建模，全面概述了全刻面晶体轮廓的形态演变，显示了在密集阵列配置的情况下，微晶之间的通量屏蔽所起的独特作用的出色预测。由于热膨胀系数不匹配而导致的裂纹形成和基板弯曲，可通过单个微晶之间的机械解耦消除，这些微晶也显示出无位错和无应变。该方法已还测试的Si _{1- X}葛_X合金，成分从纯硅到纯锗。有充分的理由相信该方法可以扩展到其他材料组合和基板方向，从而实际上为多种设备应用提供了技术平台。