Revisiting the structure zone model for sculptured silver thin films deposited at low substrate temperatures

• Published in: Journal of applied physics 2012-11, Vol.112 (10)
• Main Authors: Singh, Dhruv P., Goel, Pratibha, Singh, J. P.
• Format: Article
• Language: English
• Subjects: Deposition; Diffusion; Nanocomposites; Nanomaterials; Nanostructure; Nanowires; Silver; Thin films
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.4767634

In this study, we examined the low substrate temperature (Ts) growth mechanism of Ag thin films in the atomic shadowing regime (Ts ≪ melting point Tm). The Ag thin films were deposited using glancing angle deposition (GLAD) at different substrate temperatures varying from 320 K to 100 K. Interestingly, it is observed that on lowering the substrate temperature instead of showing a monotonic variation, the Ag film morphology changes from the ordered nanocolumns to random and distorted columns, and then to the columnar bunches of nanowires. These growth results suggest that this temperature regime of effective adatom shadowing does not hold a unique growth mechanism for the GLAD within the low temperature range from 320 K to 100 K and depending on the observed temperature dependent variation in morphological and structural properties of the Ag film, it can be sub-divided into three characteristic zones. The observed growth mechanism of the Ag film is explained in terms of the temperature dependent change in terrace diffusion and the interlayer diffusion of Ag adatoms which finally controls the formation of nucleation centers in initial stage and their evolution during the final growth. The understanding of low temperature growth mechanism along with the identification of appropriate temperature range for the growth of nanocolumnar metallic films during GLAD is the novelty in this work.