No.4（2001）13.Improvement of mechanical properties on thin metal films for MEMS applacation

Tomonori SASAKI and Ming YANG

A method of improving mechanical properties of thin films by low energy ion irradiation treatment after the deposition proposed in this study. The low energy Ar ion irradiation treatment was applied to aluminum thin films, which were widely applied to the MEMS and semiconductor device as conductive layers. Experimental results show that mechanical properties of the thin Al film deposited improved after the treatment. The surface of the thin Al films were irradiated with low energy Ar ions using a Kaufman type ion gun for 30 minutes under the conditions: base pressure 1*10-4 Pa, irradiation angle 90 degrees, acceleration voltage 50 V and current density 0.1 mA/cm2. The improvement is interpreted that Al atoms on the surface of the films migrated due to kinetic energy of Ar ion irradiation and as a result: the bond strength in the lengthwise of direction, was reinforced at the surface of the Al films. The proposed treatment method is expected to improve surface mechanical properties of thin metal films deposited by various formation techniques and conditions, using selected irradiation treatment.

Keywords
Low energy Ar ion irradiation, Al thin film, nano-indentation, Mechanical property, Sputtering

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