Determination of the thickness distribution of a graphene layer grown on a 2″ SiC wafer by means of Auger electron spectroscopy depth profiling

Abstract

Auger electron spectroscopy (AES) depth profiling was applied for determination of the thickness of a macroscopic size graphene sheet grown on 2 inch 6H-SiC (0001) by sublimation epitaxy. The measured depth profile deviated from the expected exponential form showing the presence of an additional, buffer layer. The measured depth profile was compared to the simulated one which allowed the derivation of the thicknesses of the graphene and buffer layers and the Si concentration of buffer layer. It has been shown that the C made buffer layer contains about 30% unsaturated Si. The depth profiling was 2 carried out in several points (diameter 50m), which permitted the constructing of a thickness distribution characterizing the uniformity of the graphene sheet.

Electron irradiation induced amorphous SiO2 formation at metal oxide/Si interface at room temperature; electron beam writing on interfaces

“…Figure 5 shows the concentration distributions, which best correspond to the depth profiles shown in Fig. 4 measured on the non-irradiated (virgin) and irradiated region of the sample, respectively, calculated by our trial and error evaluation method 19 , 20 . Note that the irradiation took place at room temperature.…”

“…This is however the situation presently since the thickness of the Al oxide layer is only 5 nm, while the inelastic mean free path (IMFP) of the Al KLL and Si KLL Auger electrons in Al 2 O 3 are 3.2 and 3.6 nm, respectively 34 . We used a trial and error approach to determine the composition distribution of our sample 19 , 20 . The essence of the method is that we assume a composition distribution along the depth and calculate the Auger intensities assuming that the transport of electrons can be described by the exponential attenuation law, not considering the elastic scattering.…”

Graphoepitaxy of High‐Quality GaN Layers on Graphene/6H–SiC

“…Interfaces 2014, 1400230 www.advmatinterfaces.de www.MaterialsViews.com a high-temperature sublimation process [ 8 ] developed at Linköping University. Auger electron spectroscopy, [ 9 ] was used to determine that the number of graphene layers was usually 2-3, with small regions containing up to ten graphene layers. The continuous graphene layers were covered with polymethyl methacrylate (PMMA) and patterned using electron beam lithography, to leave 1 µm wide unmasked areas in a 3 µm periodic pattern, as shown in Figure 1 a.…”