Effects of In-Situ Temperature Control on the Nanostructure of Glancing Angle Deposition Thin Films

Graham A Hunt
2013
Glancing angle deposition (GLAD) produces sculptured thin films by utilizing substrate motion to control ballistic shadowing, thereby facilitating columnar growth. GLAD relies on control over the statistical distribution of deposited atoms, which changes as a function of temperature. For this reason, it is important that we gain the ability to control substrate temperature and understand its role in film growth. By doing so we may further refine and expand the capabilities of the GLAD
more » ... This thesis begins by summarizing my experience designing a GLAD-compatible system for heating and cooling substrates. An automated heating system using (radiative) lamps was implemented and found to be capable of maintaining substrate temperatures as high as 300 °C. Liquid nitrogen was used to cool rotating substrates to temperatures as low as −50 °C, with heat transfer from a copper cooling block to the substrate holder facilitated by Graphalloy ® bushings and MoS 2 solid lubricant. Implementation of the heating system allowed the exploration of the effect of elevated substrate temperature on the column inclination angle of various materials. Results vary with material, exposing the complexity of growth mechanisms. Finally, heated substrates were leveraged to produce in situ Sn seed layers to modify the spacing of subsequently deposited GLAD posts. A linear correlation was shown to exist between the separation distances of the Sn seeds and those of GLAD posts deposited on top of the seeds, indicating an inheritance of seed position by the GLAD structures, and demonstrating this method capable of influencing GLAD post nucleation.
doi:10.7939/r3hx1622j fatcat:2kuvhrkatnfrnnwxvzuisjsdae