Segregation of Ge in B and Ge codoped Czochralski-Si crystal growth
Segregation of Ge in B and Ge codoped Czochralski-Si crystal growth
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DOI：
10.1016/j.jallcom.2015.03.155
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发表时间：
2015-08
影响因子：
6.2
通讯作者：
M. Arivanandhan;Raira Gotoh;K. Fujiwara;S. Uda;Y. Hayakawa
中科院分区：
文献类型：
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作者：
M. Arivanandhan;Raira Gotoh;K. Fujiwara;S. Uda;Y. Hayakawa
研究了B和Ge共掺直拉（CZ）硅单晶生长过程中Ge的偏析。用电子探针和X射线荧光光谱法对重掺锗直拉硅中锗的浓度进行了测量。Ge的有效偏析系数（keff）通过将EPMA数据拟合到正常凝固方程，并通过取锭的种子和尾部处的Ge浓度的对数比（顶部到底部的方法）来计算。当Si熔体中Ge的初始浓度（CL（o）Ge）从3 × 1019增加到3 × 1021cm−3时，Ge的kef从0.30增加到0.55。为了避免胞状生长，对于重Ge共掺杂晶体生长（CL（o）Ge> 3 × 1020cm−3），晶体提拉速率降低。用分配理论计算了Ge的平衡分凝系数k0，其值小于实验估计的keff。讨论了重掺Ge晶体中Ge的团簇效应导致的键能和应变能的变化。
The segregation of Ge in B and Ge codoped Czochralski (CZ)-Si crystal growth was investigated. The concentration of Ge in heavily Ge codoped CZ-Si was measured by electron probe micro analysis (EPMA) and X-ray fluorescence spectroscopy. The effective segregation coefficient of Ge (keff) was calculated by fitting the EPMA data to the normal freezing equation, and by taking the logarithmic ratio of the Ge concentrations at the seed and tail of the ingots (top to bottom approach). Thekeffof Ge increased from 0.30 to 0.55, when the initial Ge concentration in the Si melt (CL(o)Ge) was increased from 3 × 1019to 3 × 1021cm−3. To avoid cellular growth, the crystal pulling rate was decreased for heavily Ge codoped crystal growth (CL(o)Ge> 3 × 1020cm−3). The equilibrium segregation coefficient (k0) of Ge was calculated by partitioning theory, and was smaller than the experimentally estimatedkeff. The variation ofkefffromk0was discussed based on Ge clustering in the heavily Ge codoped crystal, which led to changes in the bonding and strain energies caused by the incorporation of Ge into Si.