Adhesive characteristics of Fe films deposited by ion beam sputtering with Ar ion bombardment

The adhesive characteristics of Fe films have been investigated in detail by controlling the condition of ion beam sputtering with an Ar bombardment. The voltage for Ar bombardment, V(Ar), was varied in the range between 80 and 2000 V. The internal stress sigma(int) of the Fe films was changed by controlling of V(Ar). The adhesion of the film was evaluated by a scratch test and a pull test. The adhesive force of the pull test increased with an increase of V(Ar). On the other hand, the critical load L(c) of the scratch test was varied in the range of 12-34 N. The Value of L(c) was strongly depended on sigma(int). L(c) took the minimum value at V(Ar) of 200 V, where \sigma(int)\ was the maximum value of 0.14 GPa. The shear stress sigma(s) by the scratch stylus was calculated. when the AE signal was generated, namely, the adhesive failure occurred, the total stress of the sum of sigma(s) and sigma(int) exceeded the limit value of 1.04 GPa. It was found that the results of the scratch test strongly depended on the internal stress. (C) 1999 Elsevier Science S.A. All rights reserved.