Method for forming region-selective thin film using selectivating agent

A method of forming an area-selective thin film, the method comprising:

• preparing a substrate in a chamber, the substrate including a growth region and a non-growth region, wherein the growth region is a titanium nitride film or a niobium nitride film, and the non-growth region is a silicon nitride film;
• supplying a selectivity material into the chamber in which the substrate is placed, wherein the selectivity material is trimethyl orthoformate and configured to be adsorbed to the non-growth region of the substrate;
• purging the interior of the chamber;
• supplying a niobium precursor into the chamber, wherein the niobium precursor is configured to be adsorbed to the growth region of the substrate;
• purging the interior of the chamber;
• and
• supplying a reaction material into the chamber to form the area-selective thin film, wherein the area-selective thin film is a niobium oxide film, and the niobium oxide film formed on the growth region of the substrate has a thickness that is greater than a thickness of the niobium oxide film formed on the non-growth region of the substrate, thereby improving a selectivity between the growth region and the non-growth region.