Grazing incidence means that the X-ray is exposed to the film at a very small incidence Angle (< 5°), which greatly reduces the penetration depth in the film. At the same time, the larger low incidence Angle increases the X-ray irradiation area on the sample and increases the volume of the sample participating in the diffraction. The role of GID in the structure analysis of thin films is introduced in this paper.
Example: Single-layer film GID test
In this example, the sample is a 14nm RuO2 polycrystalline film prepared on a (100) monocrystalline silicon substrate. Therefore, the signal of the thin film sample in the conventional XRD pattern is masked by the signal of the Si single crystal. Although the diffraction peaks of the thin film can be seen in the enlarged image, the signal is very weak. The GID spectrum of the sample at an incident Angle of 0.3 degrees is shown in Figure 2. There is no signal of Si single crystal substrate in the figure, and the film signal is obvious.
Fig1
Fig2