Influence of sticking coefficients on the behavior of sputtered atoms in an argon glow discharge: Modeling and comparison with experiment

Abstract

Two-dimensional sputtered lithium atom density profiles have been calculated with a model for an argon glow discharge. Since the value of the sticking coefficient of sputtered atoms at the cell walls, which is needed as the boundary condition for calculating the behavior of the sputtered atoms, is not available from the literature, the calculations were performed for a range of sticking coefficient values. It is found that this parameter has a significant effect on the calculation results, and accurate knowledge of its value would therefore be required for an exact description of the behavior of sputtered atoms in a glow discharge. The density profiles calculated have also been compared with experimental results, obtained with concentration-modulated absorption spectrometry at the same discharge conditions and in the same cell geometry, in order to try to make reasonable estimates for the sticking coefficients.

Thin-film growth dynamics with shadowing and re-emission effects

“…10,11 The prevailing effects of shadowing and re-emission rely on their "nonlocal" character: The growth of a given surface point depends on the heights of near and far-away surface locations due to shadowing and existence of re-emitted particles that can travel over long distances. Figure 4 summarizes some of the experimentally measured sticking coefficient values reported in the literature during evaporation, 33 sputtering, [34][35][36][37][38][39][40][41] and CVD [42][43][44][45][46][47][48] growth of various thin-film materials. Names of incident atoms/molecules on the growing film are also labeled.…”

Transition rates and transition rate diagrams in atomic emission spectroscopy: A review

“…(24), it should be noted that [X 0 ] and [Y 0 ] are not necessarily proportional to the (total) number densities n X , n Y of the elements X, Y in the plasma, because populations of their ions and/or prospective metastables may not be negligible relative to the population of the ground state atoms of X, Y. Also, the ratio n Y /n X will be equal to the ratio of the concentrations c X , c Y of these elements in the alloy measured only if the transport in the plasma of the sputtered atoms X, Y follows the diffusion equation [55][56][57][58] with the same boundary conditions for both elements X, Y on the anode. This condition requires the sticking coefficient [57] for both elements on the anode surface to be the same.…”

“…in a setup similar to that reported in Ref. [57]. It remains to discuss the ratio of the rates γ Ar-X /γ Ar-Y for the Ar + -ACT reactions being compared: It is relatively straightforward to determine the sum of de-excitation rates of all levels e.g.…”

“…Also, the ratio n Y /n X will be equal to the ratio of the concentrations c X , c Y of these elements in the alloy measured only if the transport in the plasma of the sputtered atoms X, Y follows the diffusion equation [55][56][57][58] with the same boundary conditions for both elements X, Y on the anode. This condition requires the sticking coefficient [57] for both elements on the anode surface to be the same. The sticking coefficients are unknown, hence, the ratio [Y 0 ]/[X 0 ] that is needed in Eq.…”

Ionized physical vapor deposition of Cu on 300 mm wafers: A modeling study

“…Early references to the use of ions assisting in conventional deposition processes include Nakai et al 1 and Bland et al 2 The phenomenology associated with this kind of configuration has been quantitatively characterized by Bogaerts and co-workers. 3,4 Earlier work was followed by methods for enhancing or controlling the ionization degree or the fate of the ions. For example, triode and more complex configurations were developed by Kloos et al 5 or supplemental discharges were added.…”