Influence of the non-uniformity of surface dielectric film thickness on cathode sputtering in a glow discharge
Special features of sputtering of the cathode with a thin dielectric film of variable thickness in a glow discharge are studied. It is shown that the flux density of atoms sputtered from the cathode is maximal on its sections with minimal film thickness due to focusing of ion flux caused by the violation of the electric field uniformity near the cathode surface. As a result, the non-uniformity of the film thickness increases with time, thereby leading to the formation of pores in the film.
A one-dimensional model kinetic equation for the energy distribution function of heavy ions in the cathode sheath of gas mixture glow dischargees is siggested.
A mathematical model of ion and sputtered atom transport in the vicinity of the target with a periodical surface relief in glow discharge in pure gas is developed. Under the assumption that the relief amplitude is small, analytical expressions for their flows are found by the perturbation method and an equation describing the relief amplitude time evolution is derived. It is shown that intensity of sputtering exceeds intensity of sputtered material redeposition at the relief tops, and relief smoothing always takes place in the process of homogeneous target treatment in glow discharge in pure gas.
An approximate analytical expression for the ion current density near the cathode in glow discharge is obtained in the presence of a periodic relief of small amplitude and an insulating oxide film of varying thickness on its surface. It is found that ion focusing at the cathode sections with the minimum film thickness, located on any parts of the surface relief, takes place, resulting in an increase of the film thickness non-uniformity with time. Therefore, under the existence of an oxide film on the cathode, its sputtering in glow discharge is determined mainly by the film thickness non-uniformity and not by the surface relief.
It has been shown that the increase of charge stability of MDS-systems can be achieved by optimal choosing the thickness of dielectric films of silicon dioxide and phosphorous soda-lime glass.
This volume presents new results in the study and optimization of information transmission models in telecommunication networks using different approaches, mainly based on theiries of queueing systems and queueing networks .
The paper provides a number of proposed draft operational guidelines for technology measurement and includes a number of tentative technology definitions to be used for statistical purposes, principles for identification and classification of potentially growing technology areas, suggestions on the survey strategies and indicators. These are the key components of an internationally harmonized framework for collecting and interpreting technology data that would need to be further developed through a broader consultation process. A summary of definitions of technology already available in OECD manuals and the stocktaking results are provided in the Annex section.