Atomic layer sensitive in-situ plasma etch depth control with reflectance anisotropy spectroscopy (RAS)
Atomic layer sensitive in-situ plasma etch depth control with reflectance anisotropy spectroscopy (RAS)
复制标题
利用反射各向异性光谱 (RAS) 进行原子层敏感原位等离子体蚀刻深度控制
DOI：
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复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
H. Fouckhardt
中科院分区：
文献类型：
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作者：
Christoph Doering;A. Kleinschmidt;Lars Barzen;J. Strassner;H. Fouckhardt
反射各向异性光谱（RAS）允许原位监测单晶III-V族半导体表面的反应离子蚀刻（RIE）。在使用RAS时，待蚀刻的样品在几乎垂直入射下用宽带线偏振光照射。通常，光谱范围在1.5和5.5 eV之间。通常，相对于时间测量光的两个正交线性偏振的光的反射率的光谱分辨差异-例如，对于沿着[110]和[-110]方向偏振的立方晶格（如大多数III-V族半导体的锌层结构）。蚀刻前沿上的局部各向异性导致反射光的椭圆偏振，从而产生RAS信号。RAS的时间和光子能量分辨光谱包括反射信息以及干涉信息。波长远高于100 nm（甚至在材料内部）的光可以成功地用于监测表面磨损，分辨率为几十纳米。被减薄的层充当光学干涉仪，导致RAS信号的法布里-珀罗振荡。在这里，我们报告RAS测量评估表面解构干法蚀刻过程中。对于低蚀刻速率，我们的实验数据显示，甚至更好的分辨率比（慢）法布里-珀罗振荡。对于某些光子能量，我们检测到单层蚀刻相关的振荡的平均反射率，这给出了最好的分辨率在蚀刻深度监测和控制，即原子尺度。
Reflectance anisotropy spectroscopy (RAS) allows for in-situ monitoring of reactive ion etching (RIE) of monocrystalline III-V semiconductor surfaces. Upon use of RAS the sample to be etched is illuminated with broad-band linearly polarized light under nearly normal incidence. Commonly the spectral range is between 1.5 and 5.5 eV. Typically the spectrally resolved difference in reflectivity for light of two orthogonal linear polarizations of light is measured with respect to time - for example for cubic lattices (like the zinc blende structures of most III-V semiconductors) polarizations along the [110] and the [-110] direction. Local anisotropies on the etch front cause elliptical polarization of the reflected light resulting in the RAS signal. The time and photon energy resolved spectra of RAS include reflectometric as well as interferometric information. Light with wavelengths well above 100 nm (even inside the material) can be successfully used to monitor surface abrasion with a resolution of some tens of nanometers. The layers being thinned out act as optical interferometers resulting in Fabry-Perot oscillations of the RAS-signal. Here we report on RAS measurements assessing the surface deconstruction during dry etching. For low etch rates our experimental data show even better resolution than that of the (slow) Fabry-Perot oscillations. For certain photon energies we detect monolayer-etch-related oscillations in the mean reflectivity, which give the best possible resolution in etch depth monitoring and control, i.e. the atomic scale.
影响因子：
6.7
作者：
Barzen, Lars;Richter, Johannes;Kopnarsk, Michael
通讯作者：
Kopnarsk, Michael
影响因子：
6.7
作者：
Barzen, Lars;Kleinschmidt, Ann-Kathrin;Kopnarski, Michael
通讯作者：
Kopnarski, Michael
影响因子：
3.7
作者：
C. Frank;J. Novák;R. Banerjee;A. Gerlach;F. Schreiber;A. Vorobiev;S. Kowarik
通讯作者：
C. Frank;J. Novák;R. Banerjee;A. Gerlach;F. Schreiber;A. Vorobiev;S. Kowarik