A new method to characterize the metallic-oxide films for grayscale lithography

In order to characterize the metallic-oxide grayscale films fabricated by laser direct writing (LDW) in indium film, a new method with micro-Raman spectroscopy and atomic force microscope (AFM) is proposed. Raman spectra exhibit the characteristic band of In2O3 centered at 490 cm−1, in which the intensities increase with the decreasing optical density of the In-In2O3 grayscale films. The mapping information of Raman spectra shows that the signal intensities of the film in the same grayscale area are uniform. Combining with the information of In-In2O3 grayscale film from AFM, the quantitative relationship between the concentration of In2O3 and the Raman signal intensity is shown. Compared with the conventional methods, the resolution of micro-Raman scattering method is appropriate, and the scanning speed is proper to analyze the structure of metallic-oxide grayscale films.