Aluminum precursor, method of forming a thin layer using the same, method of manufacturing the same, and method of manufacturing memory device

A method for manufacturing an aluminum precursor formed by mixing 1 to 3 moles of a compound represented by the following Chemical Formula 1 or following Chemical Formula 2 and 1 to 3 moles of a compound represented by the following Chemical Formula 3,

• wherein X is O or S, and R1 or R2 is each independently selected from an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms,
• wherein X is O or S, n is 1 to 5, and R1 to R4 are each independently selected from a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms,
• wherein R1, R2 and R3 are different from each other, and each independently selected from a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a dialkylamine having 1 to 6 carbon atoms, a cycloamine group having 1 to 6 carbon atoms, or a halogen atom,
• wherein the aluminum precursor is formed by mixing ethyl methyl sulfide and trimethylaluminum, or by mixing ethyl propyl ether and trimethylaluminum.