Surface texture and engineering of silver (Ag) thin films fabricated by sputtering technique are very attractive for several advanced technologies especially on surface enhanced Raman scattering (SERS) substrate. It has been known that crucial factors of highly-sensitive SERS substrate based on Ag thin films are depended on texture orientation and morphology of thin films. Although several research groups have demonstrated the controllability in the texture and surface morphology of sputtered Ag thin films, the external energy sources such as substrate bias voltage, heating the substrate during growth or post annealing and ionized magnetron sputter deposition (IMSD) are necessary to include. Such external additional techniques make a complex and high cost operation and are not available to fabricate sputtered Ag film at room temperature. Here we demonstrate a special technique to control a texture orientation of Ag thin films via using gas-timing (GT) RF magnetron sputtering. By utilizing GT technique, a dense structure and a high ratio of (111)/(200) of Ag films could be obtained without any applying additional energy sources. We found that the GT technique not only provides the ability to adjust the number of sputter species from the target, but also generates the self-energy assisted deposition which related to the atomic peening effect. Furthermore, we found that high (111)/(200) ratio of Ag films strongly affects on the SERS activity of Ag films due to hot spot effect. Our results highlight that the texture engineering of metal thin films could be accomplished by using GT technique.

Highly sensitive surface-enhanced Raman scattering substrate of Ag thin film fabricated by gas-timing RF magnetron sputtering

253rd National Meeting (2017)

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