US Patent 9859512 Substrate having rugged structure obtained from hydrophobic sol/gel material

There are provided a fine concave-convex structure substrate which is hydrophobic and excellent in heat resistance, a solution used for producing the concave-convex structure substrate, and a method for producing the concave-convex structure substrate. The concave-convex structure substrate having the concave-convex structure includes a concave-convex structure layer made of a sol-gel material, and a contact angle of water on the sol-gel material in a flat and smooth film shape is not less than 80°. The concave-convex structure substrate according to the present invention has a hydrophobic surface, and thus, in the element in which the concave-convex structure substrate is incorporated, moisture adsorption onto the surface of the concave-convex structure substrate can be prevented, thereby making it possible to lengthen a service life of the element.