Metal Salt-Containing Composition, Substrate, Manufacturing Method of Substrate

A substrate having a metal complex film formed on the surface thereof, the metal complex film being obtained by:

• applying on the surface of the substrate a solution comprising
• a metal salt,
• a polyvalent carboxylic acid having a cis-form structure of —C(COOH)═C(COOH)—, and
• a solvent,
• the molar ratio of the polyvalent carboxylic acid to the metal salt being not less than 0.5 and not more than 4.0, and the moisture content of the solution being not less than 0.05% by weight;
• and
• drying by heating at a temperature of not lower than 100° C. and not higher than 250° C.

A method for manufacturing a substrate having an oxidized metal thin film formed on the surface thereof, the method comprising:

• an application step of applying on the surface of the substrate a solution comprising
• a metal salt,
• a polyvalent carboxylic acid having a cis-form structure of —C(COOH)═C(COOH)—, and
• a solvent,
• the molar ratio of the polyvalent carboxylic acid to the metal salt being not less than 0.5 and not more than 4.0, and the moisture content of the solution being not less than 0.05% by weight;
• a primary heating step of drying by heating the solution at a temperature of not lower than 100° C. and not higher than 250° C. ;
• and
• a secondary heating step of further heating the substrate after the primary heating step at a temperature no lower than 400° C.