| AVS 54th International Symposium | |
| Advanced Surface Engineering | Tuesday Sessions |
| Session SE-TuM |
| Session: | Glancing Angle Deposition |
| Presenter: | G.D. Dice, University of Alberta, Canada |
| Authors: | G.D. Dice, University of Alberta, Canada M.J. Brett, University of Alberta, Canada D. Wang, University of Alberta, Canada J.M. Buriak, University of Alberta, Canada |
| Correspondent: | Click to Email |
We report the fabrication and characterization of an electrically variable Fabry-Perot interferometer constructed from a nanospring array placed between partially reflective mirrors. Electrostatic compression of the nanosprings provides peak transmission wavelength control. Previous work studied the compression of SiO2 nanosprings,1 and individual Si nanospring actuation through electric current applied via a contact mode atomic force microscope (AFM).2 High quality nanostructures have recently been created using the organic material tris (8-hydroxyquinoline) aluminum (Alq3), which has a significantly smaller Young's modulus than inorganic films.3 Glancing Angle Deposition (GLAD) is a single step physical vapour deposition (PVD) technique utilizing an oblique deposition angle to create porous thin film helical structures.1 Our device is constructed from three films deposited on a conductive indium tin oxide electrode. A 25 nm thick aluminum film forms both a partially reflective mirror and one parallel capacitor plate. A two turn helical Alq3 nanospring film (300 nm pitch)is then deposited via GLAD PVD. A patterned 25 nm thick layer of aluminum forms the final mirror layer and top capacitor plate. Spring compression as a function of applied voltage was measured through a conducting contact mode AFM. The measured compression varies from 0 nm at 0 V, to ~ 1.2 nm at 6 V. We calculate the Young's modulus of the deposited Alq3 to be ~ 0.93 GPa. A shift in the peak transmission wavelength from 582.4 nm to 580.8 nm was measured utilizing a fiber-coupled white light source and spectrometer as the applied voltage was raised from 0 V to 10 V. This 1.6 nm wavelength shift corresponds to a physical spring compression of 1.73 nm for the nanospring structure which has an effective refractive index of 1.42.
1 M. W. Seto, K. Robbie, D. Vick, and M. J. Brett, "Mechanical response of thin films with helical microstructure," J. Vac. Sci. Techol. B, vol. 17, pp. 2172-2177, Sep. 1999.
2 J. P. Singh, D. L. Liu. D. X. Ye, R. C. Picu, T. M. Lu, and G. C. Wang, "Metal-coated Si springs: Nanoelectromechanical actuators," Appl. Phys. Lett, vol. 84, pp. 3657-3659, Apr. 2004.
3 P. C. P. Hrudey, K. L. Westra, and M. J. Brett, "Highly ordered organic Alq3 chiral luminescent thin films fabricated by glancing-angle deposition,"Adv. Mater., vol. 18, pp. 224-228, Jan. 2006.