Desorption of argon from amorphous Cu 60Zr 40 films during crystallization

Abstract

When films are grown by sputter deposition, usually a fraction of the sputter gas is built into the films. In this study Cu 60Zr 40 was deposited by argon sputtering. As-deposited Cu 60Zr 40 films are amorphous. The amorphous films are heated in situ, resulting in the thermally activated release of argon atoms. The argon desorption rate is monitored during heating. For films with a thickness of less than 20 nm the argon desorption rate is at a maximum at the crystallization temperature. For thicker films a second desorption peak is observed at the melting temperature. The results indicate that argon atoms located closer than 20 nm to the surface can escape at the crystallization temperature. Argon atoms buried at larger depths can only desorb at temperatures very close to the melting temperature. The observed crystallization temperature was 740 K for a heating rate of 2 K s −1.