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

Abstract

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.

Mechanical Strain Induced Tunable Anisotropic Wetting on Buckled PDMS Silver Nanorods Arrays

“…The PDMS film was mounted on a custom-designed strain stage to stretch uniaxially to different ratios (ε, defined as the ratio of increase in the film length (Δ l ) over its original length ( l )). Silver films were grown over prestretched PDMS substrates by thermal evaporation of silver powder (99.9%) using oblique angle deposition (OAD) method. − For silver nanorods formation, the stretched PDMS were inclined in such a way that the substrate normal made a very high angle (α = 85°) with the direction of incident vapor flux. During the initial growth of the films, the impinging atoms form isolated nucleation centers which cast shadow for the arriving vapor flux.…”

Quick and Selective Dual Mode Detection of H2S Gas by Mobile App Employing Silver Nanorods Array

“…The nucleated islands act as shadowing centers; therefore, the larger nucleation centers will receive more impinging atoms as compared with the smaller ones, and only the larger islands will grow. The competition between limited adatom surface mobility and shadowing effect results in the evolution of the columnar structure with the growth of AgNRs in the direction of the incident vapor flux. − …”

The Effect of Glancing Angle Deposition Conditions on the Morphology of a Silver Nanohelix Array

“…The average arm width of the silver nanohelices that were deposited at 10 °C was thicker than that of the nanohelices that were deposited at −140 °C. According to the zone model [16], the overlap between adjacent nanohelices was improved by increasing the substrate temperature. The substrate cooling with liquid nitrogen would cause the slanted deposited rods to become densely distributed.…”

“…Recently, a structure zone model for sculptured silver thin films that were deposited at low substrate temperatures was investigated. A T s /T m ratio of less than 0.1 or in the range 0.2 < T s /T m < 0.3 yields a columnar structure [16]. However, the growth of metal helices depends on particular values of the coating parameters, including the substrate temperature, the spin rate, the deposition rate, the deposition angle, and the material species [2].…”