=================================================================================

In HAADF STEM images, the geometric phase analysis (GPA) method can be used to obtain quantitative strain information. [2] The degrees of strain shown in Figure 2219a are displayed using color distribution, which corresponds to the difference between the interatomic spacing of the referenced Si substrate and each region dumbbell. [3] If the interatomic spacing interval is longer than that in the reference value, it appears as a light color; otherwise, shorter spacing appears as a dark color. In the case of the RF plasma, the color distribution is diverse. In particular, the conical bump appears blue, which indicates the much higher lattice distortion differences than for the other one regions in the image. By contrast, the VHF-plasma samples show very narrow color distributions, then it can be known that significantly less plasma damage was induced by the VHF-plasma source than that by the RF-plasma source.

============================================