Evolution of strain relaxation in step‐graded SiGe/Si structures
Evolution of strain relaxation in step‐graded SiGe/Si structures
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阶梯梯度 SiGe/Si 结构中应变弛豫的演变
DOI：
10.1063/1.114126
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发表时间：
1995
影响因子：
4
通讯作者：
F. Legoues
中科院分区：
文献类型：
--
作者：
P. Mooney;J. Jordan;J. Chu;F. Legoues
通过高分辨率 X 射线衍射测量对一系列分级 SiGe/Si 结构中的应变弛豫进行了定量研究。我们表明，超过临界厚度时，当将具有较高 Ge 摩尔分数的层添加到结构中时，位错会连续成核，并且因此发生成核的失配应变基本上是恒定的。根据经验发现，即使在分级结构中，也需要较低的生长温度来抑制具有较高Ge摩尔分数的层的粗糙化。我们证明这并不是因为应变增加，而是因为Ge含量较高的层的熔化温度较低。
Strain relaxation in a series of step‐graded SiGe/Si structures has been quantitatively investigated by high‐resolution x‐ray diffraction measurements. We show that beyond a critical thickness, dislocations nucleate continuously as layers with higher Ge mole fraction are added to the structure and that the mismatch strain at which nucleation occurs is therefore essentially constant. It had been found empirically that a lower growth temperature is required to suppress roughening of layers with higher Ge mole fraction, even in graded structures. We prove that this is not because the strain increases, but rather because of the lower melting temperature of layers with higher Ge content.