Nanoscopic mechanism of Cu precipitation at small-angle tilt boundaries in Si
Nanoscopic mechanism of Cu precipitation at small-angle tilt boundaries in Si
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Si中小角度倾斜边界Cu析出的纳米机制
DOI：
10.1103/physrevb.91.235315
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
Y. Nagai
中科院分区：
文献类型：
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作者：
Y. Ohno;K. Inoue;K. Kutsukake;M. Deura;T. Ohsawa;I. Yonenaga;H. Yoshida;S. Takeda;R. Taniguchi;H. Otsubo;S. R. Nishitani;N. Ebisawa;Y. Shimizu;H. Takamizawa;K. Inoue;Y. Nagai
我们用电子显微镜、原子探针层析和从头算方法研究了提拉法生长的p型硅(Si)铸锭中(220)晶面小角度倾斜界面上的铜(Cu)析出。在析出初期，铜原子沿晶界聚集，形成亚稳态(Nm)的体心立方结构的共格层(厚度小于2 nm)。随着层的加厚，它们与(220)界面上的失配位错变得半相干，从而降低了共格应变。随后，亚稳层在平衡态转变为非共格的正交体多面体，在Si的{112}上形成相界。这些结果类似于在金属合金中发现的铜的析出过程：形成Guinier-Preston区，然后转变为平衡相。
We investigate copper (Cu) precipitation at small-angle tilt boundaries on (220) in Czochralski-grown p-type silicon (Si) ingots using transmission electron microscopy, atom probe tomography, andab initiocalculations. In the initial stage of precipitation, Cu atoms agglomerate along the boundaries, forming coherent layers (less than about 2 nm thick) ofwith a body-centered-cubic structure in a metastable state (nm). As the layers thicken, they become semicoherent with misfit dislocations on the (220) interphase boundaries, reducing coherency strains. Subsequently, the metastable layers convert into incoherent polyhedrons of orthorhombicin the equilibrium state, forming interphase boundaries on {112} in Si. These results are similar to the Cu precipitation processes found in metallic alloys: the formation of Guinier-Preston zones followed by a conversion into the equilibriumphase.