We report polarized Raman scattering results of Ge_1−ySn_y (0 ≤ y ≤ 0.09) epitaxial layers grown on Ge‐buffered Si substrates. Polarized Raman spectra from the sample surfaces revealed strong Ge–Ge longitudinal optical (LO) phonon responses. The Ge–Ge LO(z) phonon wavenumber decreased systematically as the Sn content increased. Linear fitting results of the Ge–Ge LO(z) phonon wavenumber shifts as a function of Sn content suggested that a partial strain relaxation occurred in the Ge_1−ySn_y layers. Spatially resolved Raman mapping measurements from the cross section of a Ge_0.938Sn_0.062 samplev showed that the peak wavenumber of the Ge–Ge transverse optical phonon decreased gradually toward the top surface, providing direct evidence that the residual built‐in strain initially formed at the Ge_0.938Sn_0.062/Ge interface tended to relax gradually along the growth direction. Further, a hydrogen inductively coupled plasma treatment induced a greater homogeneous strain profile in the Ge_0.938Sn_0.062 layer.

中文翻译：

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Ge1-ySny外延结构中光子的演化

我们报告极化的Ge拉曼散射结果_{1- Ý}锡_ý（0≤ Ý ≤0.09）上生长的锗缓冲Si衬底的外延层。样品表面的极化拉曼光谱显示出较强的Ge-Ge纵向光学（LO）声子响应。随着Sn含量的增加，Ge–Ge LO（z）声子的波数会系统地降低。Ge–Ge LO（z）声子波数位移随Sn含量变化的线性拟合结果表明，在Ge _{1- y} Sn _y层中发生了部分应变松弛。Ge _0.938 Sn _0.062横截面的空间分辨拉曼映射测量samplev表明，Ge-Ge横向光学声子的峰值波数朝着顶表面逐渐减小，这直接证明了最初在Ge _0.938 Sn _0.062 / Ge界面形成的残余内建应变趋于沿生长方向逐渐松弛。 。此外，氢感应耦合等离子体处理在Ge _0.938 Sn _0.062层中引起更大的均匀应变分布。