| AVS 58th Annual International Symposium and Exhibition | |
| Advanced Surface Engineering Division | Tuesday Sessions |
| Session SE+TF-TuA |
| Session: | Glancing Angle Deposition (GLAD) II |
| Presenter: | Joshua Siewert, University of Alberta, Canada |
| Authors: | J.M. Siewert, University of Alberta, Canada J.M. LaForge, University of Alberta, Canada M.T. Taschuk, University of Alberta, Canada M.J. Brett, University of Alberta, Canada |
| Correspondent: | Click to Email |
With growing application of glancing-angle deposition (GLAD) thin films, there is increasing need to understand and engineer GLAD growth mechanics. Devices that make use of GLAD films, such as RH sensors, optical filters, and solar cells require precise knowledge and control of GLAD nanostructure. Typically, GLAD vertical post diameters are described by a power law, d = w0hp , where d is column diameter, h is height, and w0 and p are material dependent constants which describe column diameter and broadening, respectively [1, 2]. Based on theoretical growth models, p is expected to range from 5/16 to 1/2. While many GLAD materials have been characterized for p, reliable trends have not yet been obtained [2,3,4,5].
Most groups measure p from cross-sectional SEM images, recording diameters of clearly distinct posts as a function of height. This technique is labour-intensive and large scatter in the data has been observed [4]. One alternative, focused ion-beam cross sections of GLAD films [5], produces very precise measurements but is impractical for characterizing the ensemble properties of a GLAD film. In both cases, the limited number of measurements restricts what can be learned about GLAD films.
To eliminate this limitation, we have been developing an automated characterization method for GLAD posts that enables effective measurement of thousands of posts. Using this technique, we have measured p and w0 as a function of pitch for 1500 nm TiO2, 81° deposition angle, vertical post films. We examine post growth for “extinct” and full height posts, discovering markedly different growth scaling behaviors. Characterization of phi-sweep slanted post structures is underway. We will present the optimized technique, current experimental results, and comparisons of automated measurements with existing measurement methodologies.
[1] T. Karabacak, J. Singh, Y.-P. Zhao, G.-C. Wang, and T.-M. Lu, Phys. Rev. B, vol. 68, Sep. 2003.
[2] C.M. Zhou and D. Gall, J. Appl. Phys., vol. 103, Jan. 2008, p. 014307.
[3] C. Buzea, G. Beydaghyan, C. Elliott, and K. Robbie, Nanotechnology, vol. 16, Oct. 2005, pp. 1986-92.
[4] M.T. Taschuk, K.M. Krause, J.J. Steele, M.A. Summers, and M.J. Brett, J. Vac. Sci. Technol. B. vol. 27, 2009, p. 2106.
[5] K.M. Krause, D.W. Vick, M. Malac, and M.J. Brett, Langmuir, vol. 26, Nov. 2010, pp. 17558-67.