AVS 50th International Symposium
    Thin Films Wednesday Sessions
       Session TF-WeP

Paper TF-WeP31
Improvement of Corrosion Resistance of Transparent Conductive Multi-layer Coatings Consisting of Silver Layers and Transparent Metal Oxide Layers

Wednesday, November 5, 2003, 11:00 am, Room Hall A-C

Session: Poster Session
Presenter: K. Koike, Mitsui Chemicals, Inc., Japan
Authors: K. Koike, Mitsui Chemicals, Inc., Japan
F. Yamazaki, Mitsui Chemicals, Inc., Japan
T. Okamura, Mitsui Chemicals, Inc., Japan
S. Fukuda, Mitsui Chemicals, Inc., Japan
Correspondent: Click to Email
We have investigated transparent conductive multi-layer sputter coatings consisting of silver (Ag) layers and transparent metal oxide layers. We could expect versatile applications for the multi-layer sputter coatings, such as a transparent electrode and a transparent electromagnetic waves shield. The multi-layer sputter coatings including the silver layer is very sensitive to surrounding atmosphere. For example we would find discolored points on the multi-layer sputter coatings, possibly caused by a silver atom migration in silver layers, after an exposure test. In our investigation, we modified a top surface of the multi-layer sputter coatings with transition metals to improve a corrosion resistance of the multi-layer coatings. Specifically we deposited the transition metals with 0.5 to 2nm thickness on the top surface of the multi-layer coatings by sputtering. We chose indium tin oxide (ITO) as the transparent metal oxide. We applied the multi-layer sputter coatings of 7 layers formed on a polyethylene terephthalate (PET) film substrate. A cross-sectional structure of the film with the multi-layer coatings is PET film / ITO / Ag /ITO / Ag / ITO / Ag / ITO. We evaluated the corrosion resistance by a salt water immerse test. In the test we immerse the film with multi-layer coatings into salt water, and then evaluate an appearance, a transmittance and an electrical resistance of the multi-layer coatings. We investigated several transition metals as the modifying material, and we found that titanium and tantalum drastically improved a resistance of the multi-layer coatings against the salt water without a significant decline of a transmittance. We also investigated a relation between an elapsed time after the depositing the modifying materials and the resistance against the salt water. Further we investigated effects of a heat treatment and an oxide plasma treatment on the resistance against the salt water.