Strain relaxation mechanism in a reverse compositionally graded SiGe heterostructure
Strain relaxation mechanism in a reverse compositionally graded SiGe heterostructure
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DOI：
10.1063/1.2472135
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发表时间：
2007-02
影响因子：
4
通讯作者：
L. Wong;J. P. Liu;F. Romanato;C. Wong;Y. Foo
中科院分区：
文献类型：
--
作者：
L. Wong;J. P. Liu;F. Romanato;C. Wong;Y. Foo
提出了SiGe外延中的成分反渐变（RG）概念，即在RG/Si界面处，梯度层的晶格失配开始于最高值，并在SiGe/RG界面处逐渐减小到最后的失配。使用各种表征技术，作者表明，这种低位错密度的应变弛豫机制依赖于大的成核速率的失配位错在陡峭的RG/Si界面和减少的SiGe/RG界面的螺纹位错通过促进滑移。RG概念能够在薄缓冲层上生长高质量的弛豫外延层，适合作为许多微电子和光电应用的衬底。
A concept of compositional reverse-grading (RG) in SiGe∕Si heteroepitaxy has been proposed, in which the graded layer lattice mismatch starts at the highest value at the RG/Si interface and decreases to a final mismatch at the SiGe/RG interface. Using various characterization techniques, the authors show that this low-dislocation-density strain relaxation mechanism relies on the large nucleation rates of misfit dislocations at the abrupt RG/Si interface and the reduction of threading dislocations at the SiGe/RG interface by facilitating glide. The RG concept enables the growth of high-quality relaxed epitaxial layer on a thin buffer layer, suitable as a substrate for many microelectronic and optoelectronic applications.