Visible light irradiation effects on chemical bonding structure of amorphous carbon nitride thin films using synchrotron radiation infrared rays

Abstract Using high-intensity infrared (IR) rays from the SPring-8 synchrotron radiation, we investigated the relationship between the photo-induced deformation and the in-plane distribution of the chemical bonding state of amorphous carbon nitride (a-CNx) thin films prepared via reactive sputtering. The film deposited at 573 K has the largest amount of photo-induced deformation and the film deposited at 873 K shows no photoresponse. When the beam diameter was reduced to a few micrometers, the films were irradiated with IR rays to obtain the IR spectra at each point on the film surface. Consequently, it was discovered that the chemical bonding state of the a-CNx thin films was not uniform in the plane, and that the spectral intensity in the range of 1100–1800 cm−1 was stronger or weaker depending on the location. When irradiated with a visible light laser, the absorption band spectral intensity was assigned based on a sixfold ring structure containing nitrogen and the C N chain increased by 8%–10% in a film that underwent photo-induced deformation. In the a-CNx film with no photo-induced deformation, no IR spectral irradiation change was observed.