PURPOSE: A method for manufacturing an aluminum nitride thin film having an improved surface and combination characteristic is provided to improve a surface planarization at a low process temperature and a chemical and electrical characteristic of the thin film, by processing the aluminum nitride thin film deposited by a low temperature process while using microwave plasma. CONSTITUTION: An aluminum nitride thin film is deposited. A microwave plasma process as a subsequent process of the aluminum nitride thin film is carried out. One of nitrogen gas, hydrogen gas and ammonia gas is selected as chemical reaction gas used in the plasma process.