Wang Yun-Yu, Jin Qiang, Zhuang Kent, Choi Jae Kyu, Nxumalo Jochonia
Micron Technology, 8000 S. Federal Way, Boise, ID 83716, USA.
Micron Technology, 8000 S. Federal Way, Boise, ID 83716, USA.
Ultramicroscopy. 2021 Jan;220:113164. doi: 10.1016/j.ultramic.2020.113164. Epub 2020 Nov 2.
An energy band gap measurement method based on nano-beam STEM with small off-axis angle valence band transmission electron energy loss spectroscopy (TEELS) is reported. The effect of multiple scattering event is removed by self-convolution method to obtain a single scattering loss function and a dielectric function is calculated from the single scattering valence band energy loss function through Kramers-Kronig (K-K) analysis. Optical band gaps are extracted from energy loss spectra and the imaginary part of the dielectric functions for crystalline and amorphous SiO, SiN, and SiON through linear fitting of on-set regions yielding results that are independent of sample thickness. The TEELS band gap data are consistent with those obtained from reflection electron energy loss spectroscopy (REELS) measurements.
报道了一种基于具有小离轴角价带透射电子能量损失谱（TEELS）的纳米束扫描透射电子显微镜（STEM）的能带隙测量方法。通过自卷积方法消除多次散射事件的影响，以获得单次散射损失函数，并通过克莱默斯-克勒尼希（K-K）分析从单次散射价带能量损失函数计算介电函数。通过对起始区域进行线性拟合，从能量损失谱以及晶体和非晶硅氧化物、氮化硅和氮氧化硅的介电函数虚部中提取光学带隙，得到与样品厚度无关的结果。TEELS带隙数据与反射电子能量损失谱（REELS）测量获得的数据一致。
