Thin-film device and method of manufacturing same

A method of manufacturing a thin-film device comprising a substrate, a flattening film made of an insulating material and disposed on the substrate, a lower conductor layer disposed on the flattening film, a dielectric film disposed on the lower conductor layer, and an upper conductor layer disposed on the dielectric film, wherein:

• the dielectric film has a thickness that falls within a range of 0.02 to 1 μm inclusive and that is smaller than a thickness of the lower conductor layer;
• a portion of a top surface of the substrate is exposed at a top surface of the flattening film;
• a surface roughness in maximum height of the top surface of the flattening film is smaller than a surface roughness in maximum height of the top surface of the substrate and is equal to or smaller than the thickness of the dielectric film;
• and a surface roughness in maximum height of a top surface of the lower conductor layer is equal to or smaller than the thickness of the dielectric film, the method comprising the steps of:
• forming the flattening film on the substrate;
• polishing the top surface of the flattening film so that the portion of the top surface of the substrate is exposed at the top surface of the flattening film,
• forming the lower conductor layer on the flattening film;
• forming the dielectric film on the lower conductor layer;
• and
• forming the upper conductor layer on the dielectric film.