The crystallization of amorphous metal oxide thin films was achieved by RF plasma treatment. Although various amorphous films are crystallized after 2 min or so, the sample temperature is lower than 150 degrees C without compulsory cooling even when the films are treated for I It. The oxygen gas pressure on the plasma treatment was found to be the key parameter on the crystallization. This treatment works on amorphous films of various materials, independently of the film preparation method and substrate materials. (c) 2005 Elsevier B.V. All rights reserved.