Method of forming silicon oxycarbonitride film

1. A method of forming a silicon oxycarbonitride film on a base, the method comprising stacking a silicon carbonitride film and a silicon oxynitride film on the base to form the silicon oxycarbonitride film.

2. The method of claim 1 , wherein forming of the silicon carbonitride film and forming of the silicon oxynitride film are repeatedly performed.

3. The method of claim 1 , wherein forming of the silicon carbonitride film comprises a carbonization process and a nitriding process of a silicon film, and forming of the silicon oxynitride film comprises an oxidation process and a nitriding process of a silicon film.

4. The method of claim 3 , wherein when the silicon carbonitride film is formed, the carbonization process and the nitriding process of the silicon film are repeatedly performed.

5. The method of claim 3 , wherein when the silicon oxynitride film is formed, the oxidation process and the nitriding process of the silicon film are repeatedly performed.

6. The method of claim 3 , wherein a concentration of oxygen in the silicon oxycarbonitride film that is formed is controlled by controlling an order of performing the oxidation process and the nitriding process of the silicon film.

7. The method of claim 6 , wherein the concentration of the oxygen in the formed silicon oxycarbonitride film is controlled within a range from 20 at. % to 35 at. %.

8. The method of claim 1 , wherein a refractive index of the formed silicon oxycarbonitride film when a wavelength of light is 633 nm ranges from 1.72 to 1.90.

9. The method of claim 6 , wherein the concentration of the oxygen in the formed silicon oxycarbonitride film is controlled within a range from 20 at. % to 30 at. %.

10. The method of claim 1 , wherein a refractive index of the formed silicon oxycarbonitride film when a wavelength of light is 633 nm ranges from 1.77 to 1.90.