Symmetrically strained Si/Ge superlattices on Si substrates.
Symmetrically strained Si/Ge superlattices on Si substrates.
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Si 衬底上的对称应变 Si/Ge 超晶格。
DOI：
10.1103/physrevb.38.3599
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
G. Abstreiter
中科院分区：
文献类型：
--
作者：
Erich Kasper;H. Kibbel;H. Jorke;H. Brugger;E. Frieß;G. Abstreiter
对称应变Si/Ge超晶格的总厚度为0.2 \ensuremath{\mu}m，远高于临界厚度（\ensuremath{\cong} 10 nm）的非对称应变超晶格的相同的组成，进行了研究。应变调节是通过在Si衬底上生长薄的均匀的${\mathrm{Si}}_{0.4}$${\mathrm{Ge}}_{0.6}$缓冲层（20 nm）来实现的。周期长度在0.7-2.8 nm范围内变化。拉曼散射实验定量地证实了应变分布和超晶格周期性。观察到的带折叠的声学声子能量同意理论预期的色散关系。
Symmetrically strained Si/Ge superlattices with an overall thickness of 0.2 \ensuremath{\mu}m, well above the critical thickness (\ensuremath{\cong} 10 nm) of unsymmetrically strained superlattices of the same composition, are studied. Strain adjustment is obtained by growing thin homogeneous ${\mathrm{Si}}_{0.4}$${\mathrm{Ge}}_{0.6}$ buffer layers (20 nm) on Si substrates. The period lengths vary in the range 0.7-2.8 nm. Raman scattering experiments confirm quantitatively the strain distribution and the superlattice periodicity. Observed zone-folded acoustic-phonon energies agree well with theoretically expected dispersion relations.