Film formation method
A film formation method having an excellent mass productivity, whereby a time required for forming a film having a desired thickness is short. In the film formation method, at least one of a metal complex having two or more different ligands, and a metal complex having same ligands and substituents is used, and the method includes atomizing or dropletizing a liquid containing the metal complex, conveying resulting mist or droplets to a base by a carrier gas, and forming a metal oxide film on the base by thermally reacting the mist or droplets in the vicinity of the base.
1 . A film formation method, the method comprising steps of:
atomizing or dropletizing a liquid containing a metal complex, the metal complex being at least one of:
a metal complex having two or more different ligands, and
a metal complex having same ligands and substituents;
conveying a resulting mist or droplets to a base by a carrier gas; and
forming a metal oxide film on the base by thermally reacting the mist or droplets in the vicinity of the base, wherein
the two or more different ligands include at least one ligand represented by following formula (1) and at least one ligand selected from a group consisting of a ligand derived from acetylacetonato, a ligand having a heterocyclic structure, and the ligand represented by following formula (1), and
in following formula (1), the dotted line represents a coordinate bond, *1 represents a coordinate bond position with a metal, *2 represents a bond position with a metal, and each of R 1 and R 2 independently represents an alkyl group having 1 to 6 carbon atoms,
the metal complex having the same ligands and substituents is represented by following formula (2), and
in following formula (2), the dotted line represents a coordinate bond, each of R 3 and R 4 independently represents hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, a phenyl group, or a tolyl group, R 5 represents a halogen atom, a formyl group, an acetoxy group, a sulfo group, a mesyl group, a nitro group, a nitroso group, a phosphoryl group, or an alkyl group having 1 to 6 carbon atoms, and X represents a central metal
2 . The film formation method according to claim 1 , wherein a central metal coordinated in the metal complex having the two or more different ligands, and the central metal represented by X in the metal complex represented by formula (2) are each, independently, a d-block metal or a Group 13 metal in the periodic table.
3 . The film formation method according to claim 2 , wherein the central metals contain a Group 9 metal in the d-blocker.
4 . The film formation method according to claim 2 , wherein the central metals are iridium.
5 . The film formation method according to claim 4 , wherein the metal complex having iridium as the central metal is represented by the following formula (3) or formula (4),
in formula (3) and (4), the dotted line represents a coordinate bond, and
in formula (4), R 5 represents a halogen atom, a formyl group, an acetoxy group, a sulfo group, a mesyl group, a nitro group, a nitroso group, a phosphoryl group, or an alkyl group having 1 to 6 carbon atoms
6 . The film formation method according to claim 1 , wherein a metal oxide film is formed using the metal complex as a raw material.
7 . The film formation method according to claim 6 , wherein the metal oxide film comprises a crystalline oxide semiconductor.
8 . The film formation method according to claim 1 , wherein the base has a corundum structure.
9 . The film formation method according to claim 8 , wherein at least a part of the base comprises a crystal growth plane containing gallium as a major component.
10 . The film formation method according to claim 1 , wherein
the metal complex is contained in a liquid raw material, and
the raw material further contains gallium.
11 . The film formation method according to claim 1 , wherein
the metal complex is contained in the liquid raw material, and
the raw material further contains a p type dopant.
12 . A film formation method, the method comprising a step of forming a metal oxide film on a base by applying a liquid containing a metal complex on the base, followed by drying, wherein
the metal complex is at least one of:
a metal complex having two or more different ligands, and
a metal complex having same ligands and substituents,
the two or more different ligands include at least one ligand represented by following formula (1) and at least one ligand selected from a group consisting of a ligand derived from acetylacetonato, a ligand having a heterocyclic structure, and the ligand represented by following formula (1), and
in following formula (1), the dotted line represents a coordinate bond, *1 represents a coordinate bond position with a metal, *2 represents a bond position with a metal, and each of R 1 and R 2 independently represents an alkyl group having 1 to 6 carbon atoms,
the metal complex having the same ligands and substituents is represented by following formula (2), and
in following formula (2), the dotted line represents a coordinate bond, each of R 3 and R 4 independently represents hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, a phenyl group, or a tolyl group, R′ represents a halogen atom, a formyl group, an acetoxy group, a sulfo group, a mesyl group, a nitro group, a nitroso group, a phosphoryl group, or an alkyl group having 1 to 6 carbon atoms, and X represents a central metal