The present invention provides a method of forming a thin film containing a metal oxide as the main component, the film thickness of which is relatively uniform, at a high film deposition rate over a wide area and over a long time. The present invention is a method for forming a thin film containing a metal oxide as the main component on a substrate using a mixed gas stream containing a metal chloride, an oxidizing material, and hydrogen chloride, by a thermal decomposition method at a film deposition rate of 4500 nm/min. or greater, performing at least one selected from: 1) prior to mixing the metal chloride and the oxidizing material in the mixed gas stream, contacting hydrogen chloride with at least one selected from the metal chloride and the oxidizing material, and 2) forming a buffer layer in advance on a surface of the substrate on which the thin film containing a metal oxide as the main component is to be formed.
The present invention provides a transparent substrate with a transparent conductive film that is thin but has a surface with concavities and convexities of increased height. A manufacturing method of the present invention includes a process of forming a transparent conductive film containing crystalline metal oxide as its main component on a transparent substrate by a pyrolytic oxidation method. In the method, a gaseous material containing a metal compound, an oxidizing material, and hydrogen chloride is supplied onto the transparent substrate. The process includes sequentially: a first step in which a mole ratio of the hydrogen chloride to the metal compound in the gaseous material is 0.5 to 5; and a second step in which the mole ratio is 2 to 10 and is higher than the mole ratio to be employed in the first step. With the present invention, a transparent substrate with a transparent conductive film can be provided that has a haze ratio of at least 15% and includes a transparent conductive film whose thickness is 300 nm to 750 nm.
