Deformation potential constants of biaxially tensile stressed Ge epitaxial films on Si(100)
Deformation potential constants of biaxially tensile stressed Ge epitaxial films on Si(100)
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DOI：
10.1103/physrevb.70.155309
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发表时间：
2004-10-01
影响因子：
3.7
通讯作者：
Kimerling, LC
中科院分区：
文献类型：
--
作者：
Liu, JF;Cannon, DD;Kimerling, LC
用X射线衍射和光反射测量相结合的方法，测定了在Si(100)衬底上生长的Ge外延膜的伽马点的形变势能常数。利用超高真空化学气相沉积技术在不同温度下生长Ge薄膜，并通过背面硅化处理实现了Ge薄膜的面内拉伸应变。光反射测量和数据分析给出了从轻空穴和重空穴的极大值到伽马谷底的直接带隙，即E-g(伽马)(Lh)和E-g(伽马)(HH)。根据X射线衍射法测得的直接带隙与面内应变的关系，确定了Ge_a的直接带隙的伸缩形变势为-8.97+/-0.16 eV，价带b的剪切形变势为-1.88+/-0.12 eV。这些Ge的基本常数对于基于外延Ge的应变工程器件的设计是非常重要的。
The deformation potential constants at the Gamma point of Ge epitaxial films on Si(100) were determined by a combination of x-ray diffraction and photoreflectance measurements. The in-plane tensile strain in the Ge thin films was engineered by growth at different temperatures in ultrahigh vacuum chemical vapor deposition and by backside silicidation. Photoreflectance measurements and data analysis give the direct band gaps from the maxima of the light- and the heavy-hole bands to the bottom of Gamma valley, namely, E-g(Gamma)(lh) and E-g(Gamma)(hh). From the relationship between the direct band gap and the in-plane strain measured by x-ray diffraction, the dilational deformation potential of the direct band gap of Ge a, and the shear deformation potential of the valence band b were determined to be -8.97+/-0.16 eV and -1.88+/-0.12 eV, respectively. These basic constants of Ge are very important for the design of strain-engineered devices based on epitaxial Ge.