Integrated diffusion–recombination model for describing the logarithmic time dependence of plasma damage in porous low- k materials

• Published in: Microelectronic engineering Vol. 88; no. 5; pp. 631 - 634
• Main Authors: Kunnen, E., Barkema, G.T., Maes, C., Shamiryan, D., Urbanowicz, A., Struyf, H., Baklanov, M.R.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.2011; Elsevier
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Damage; Diffusion; Diffusion in nanoscale solids; Diffusion in solids; Exact sciences and technology; Fractures; Low- k; Materials science; Mathematical analysis; Mathematical models; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Oxygen atoms; Oxygen plasma; Physics; Plasma damage; Porous; Porous materials; Porous materials; granular materials; Radicals; Recombination; Specific materials; Time dependence; Transport properties of condensed matter (nonelectronic); Plasma damage; Recombination; Diffusion; Low- k; Porous; Oxygen; Random walk; Porous material; Time dependence; Low-k; Random walk model; Depth profile; Vacuum ultraviolet radiation; Low k dielectric; Damaging
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2010.07.014

This work proposes an extended model that describes the propagation of damage in porous low- k material exposed to a plasma. Recent work has indicated that recombination and diffusion play a more dominant role than VUV light [1–5] in oxygen plasma induced damage. Especially at low depths, the radical concentration is determined by the number of radicals that disappear back into the plasma while the final depth of damage is defined by recombination of oxygen atoms. A logarithmic equation has been proposed to describe the behavior as a function of time. In this work this equation is extended to take diffusion into account, next to recombination. The results are in agreement with experimental data and one-dimensional random walk theory calculations.