The importance of non-local shadowing for the topography evolution of a-C:H films grown by toluene based plasma enhanced chemical vapor deposition

Abstract

The topography evolution of hydrogenated diamondlike carbon coatings deposited through toluene based capacitively coupled plasma enhanced chemical vapor deposition has been studied experimentally and with continuum growth models. The experimentally observed mound formation and surprisingly large growth exponents β ≈ 0.9 ± 0.1 cannot be reproduced by familiar local stochastic differential equations that are successfully used for other thin film deposition techniques. Here we introduce a novel numerical approach to simulate a continuum growth model that takes into account non-local shadowing effects. We show that the major characteristics of the experimentally observed topography evolution can be accurately represented by this model.

Dynamical renormalization group study for a class of non-local interface equations

“…A growth exponent value β = 0.74 was measured, which suggests that an underlying morphological instability is responsible for the cauliflower-like morphology observed at the late stages of the growth process, that looks quite similar to that found in [42]. Further, in [72] a large growth exponent (β = 0.9 ± 0.1) is reported for hydrogenated diamond-like carbon (a-C:H) coatings deposited through plasma enhanced CVD. In general, it would be interesting to search for experimental parameters/techniques that allow to tune the value of µ characterizing a putative continuum description through equation (4), in order to probe the corresponding continuum line of fixed points.…”

Ion beam nanopatterning of III-V semiconductors: consistency of experimental and simulation trends within a chemistry-driven theory

“…These have included a linear “damped” version 42 an “extended” version with an extra nonlinear term 43 . Even more recently, the effect of long-range redeposition of sputtered atoms has been considered, which produces a nonlocal effect 44 45 46 that is also nonlinear 47 . For normal incidence irradiation, these results may be summarized in the single equation…”

“… 43 to describe arrested coarsening. Finally, the term describes the (nonlocal) effect of long-range atomic redeposition considered in refs 44 , 45 , 46 .…”

Redox Route from Inorganic Precursor Li2C2 to Nanopatterned Carbon

“…It is argued that amorphous carbon forms such finite clusters in order to relieve strain . Beyond pure amorphous carbon, there exist a variety of hydrogenated amorphous carbons, ranging from polymeric to tetrahedral diamond-like depending on hydrogen content. , …”

“…35 Beyond pure amorphous carbon, there exist a variety of hydrogenated amorphous carbons, ranging from polymeric to tetrahedral diamond-like depending on hydrogen content. 36,37 Our approach for fabricating nanopatterned amorphous carbon is based on lithium carbide (Li 2 C 2 ) as educt. The synthesis of Li 2 C 2 was described first by Juza et al 38 The crystal structure of the low-temperature modification was determined as orthorhombic (space group Immm), whereas the hightemperature phase was found to be cubic (space group Fm3̅ m).…”