Crystallization of sputtered Cu60Zr40 studied by thermal desorption

• Published in: Vacuum 1990, Vol.40 (3), p.257-262
• Main Authors: van der Kolk, GJ, Minemura, T, van Veen, A, Bijkerk, KR
• Format: Article
• Language: English
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/0042-207X(90)90040-6

A novel method is used for studying the crystallization of amorphous Cu-Zr film. When film are grown by sputter deposition they usually contain a friction of the sputter gas. In this investigation a Cu60Zr40 target was sputtered in an Ar plasma and an amorphous Cu-Zr film was grown containing 0.13 at. % of Ar. The as-deposited film was heated in situ linearly with time resulting in the release of trapped Ar atoms. The Ar desorption rate is at maximum at the crystallization temperature (740 K at a heating rate of 2 K s−1. A very narrow (20K) desorption peak is observed, which is comparable in width with the crystallization peak observed in differential scanning calorimetry experiments. By varying the film thickness it was found that only those Ar atoms located closer than about 15 nm to the film surface were released at the crystallization temperature. Ar atoms located at greater depths could only desorb when the film temperature was close to the melting temperature of the film material. By variation of the heating rate during the desorption step an effective activation energy was derived of 1.7 ± 0.2 eV. The large discrepancy between the value found and those reported in the literature is discussed. The substrate temperature during deposition was varied and at temperature higher than 450 the trapped fraction of Ar was drastically reduced.