Strain due to nickel diffusion into hydrogen-terminated Si(1 1 1) surface
Strain due to nickel diffusion into hydrogen-terminated Si(1 1 1) surface
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由于镍扩散到氢封端的 Si(1 1 1) 表面而产生的应变
DOI：
10.1016/s0169-4332(01)00852-2
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发表时间：
2002
影响因子：
6.7
通讯作者：
K. Hirose
中科院分区：
文献类型：
--
作者：
T. Emoto;K. Akimoto;A. Ichimiya;K. Hirose
我们研究了薄的影响（即，用应变敏感X射线衍射方法研究了氢终止Si（111）衬底上的Ni薄膜（0.2-0.8nm）。据报道，Ni沉积到氢终止的Si表面上显然不会引起膜生长，而是扩散到Si晶体中，产生高达0.8nm厚的Ni沉积的“Ni扩散层”。测量的Si 113反射的摇摆曲线和衬底的摇摆曲线的积分强度提供关于在Ni扩散到衬底期间在衬底表面附近引入的应变场的演变的信息。比较测量和计算的摇摆曲线表明，Si的{111}间距的压缩逐渐发生直到Ni厚度为0.6nm，并且在此厚度以上，发生应变弛豫。我们发现，摇摆曲线与X射线波长的积分强度的斜率与表面附近的应变场相关，以同样的方式，摇摆曲线的形状与表面附近的应变场相关。动态衍射计算表明，相对于X射线波长的摇摆曲线的积分强度的斜率的测量是有用的应变分析，因为依赖性不仅是敏感的应变场，但也不敏感的覆盖层的吸收的效果，否则会导致变形的摇摆曲线的形状。
We studied the affection of thin (i.e., 0.2–0.8nm) Ni films on hydrogen-terminated Si(111) substrate surface by using strain-sensitive X-ray diffraction. It was reported that Ni deposition onto hydrogen-terminated Si surface apparently does not cause film growth, but rather diffuses into the Si crystal, creating an “Ni diffusion layer” up to Ni deposition 0.8nm thick. Measured rocking curves of the Si 113 reflection and integrated intensities of the rocking curves for the substrate provide information about the evolution of the strain field introduced near the substrate surface during Ni diffusion into the substrate. Comparing the measured and calculated rocking curves indicates that compression of the {111} spacing of the Si occurs gradually up to an Ni thickness of 0.6nm, and that above this thickness, strain relaxation occurs. We found that the slope of the integrated intensity of the rocking curve versus X-ray wavelength correlates to the strain field near the surface, in the same way that the shape of the rocking curves correlate to the strain field near the surface. Dynamical diffraction calculations indicate that measurement of the slope of the integrated intensity of the rocking curve versus X-ray wavelength is useful for strain analysis, because the dependence is not only sensitive to strain fields, but is also insensitive to the effect of absorption by the overlayer, which otherwise would cause deformation of the shape of the rocking curve.