Unstable kinetic roughening during the island coalescence stage of sputtered tantalum films

Abstract

Kinetic roughening of tantalum films during the initial growth stages has been studied by atomic force microscopy, scanning electron microscopy, and dynamic scaling theory. Different from the time-independent scaling behavior for continuous film growth, an intriguing unstable kinetic roughening occurs during island coalescence. In such case, roughness exponent α increases with growth time, accompanied by lower growth exponent β and higher coarsening exponent η. Detailed analysis of film surface morphology and simple phenomenological models suggests that this unstable behavior is related to the pronounced lateral growth of surface islands, which arises from the combined effect of the formation of grain boundary and the covering of heterogeneous substrate surface.

Co-catalytic Absorption Layers for Controlled Laser-Induced Chemical Vapor Deposition of Carbon Nanotubes

“…This relates to the morphology of the thin Ta layers on these substrates: sputter deposition initially leads to island formation, before forming continuous layers for increasing deposition time. 47 Hence lateral heat conduction is negligible in the initial island formation stage and heat losses equate to q̇r gs . To reconstruct the phase boundary, we fit the acquired data using tabulated material properties of Ta 48 (α = 4.42 × 10 5 cm −1 , R = 0.37, from Fresnel equations).…”

Surface Dynamics Transition of Vacuum Vapor Deposited CH3NH3PbI3 Perovskite Thin Films

“…At the second stage ( ≥ 200 s), values are almost invariant and the average value is about 0.83. This indicates the stable kinetic roughening corresponding to continuous film growth at this stage [13].…”

Suppression of surface roughening kinetics of homogenously multilayered W films

“…Based on these AFM measurements, we used a height-height correlation function G(r) to calculate the scaling exponents of W sublayer. G(r) is defined as 25 GðrÞ ¼ h½hðx; yÞ À hðx 0 ; y 0 Þ 2 i;…”