Relation between the RF discharge parameters and plasma etch rates, selectivity, and anisotropy
| Autor: | C. B. Zarowin |
|---|---|
| Rok vydání: | 1984 |
| Předmět: |
Debye sheath
Plasma etching Chemistry fungi technology industry and agriculture Analytical chemistry macromolecular substances Surfaces and Interfaces Plasma Condensed Matter Physics Plasma oscillation Surfaces Coatings and Films symbols.namesake stomatognathic system Electric field symbols Reactive-ion etching Electric current Atomic physics Excitation |
| Zdroj: | Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films. 2:1537-1549 |
| ISSN: | 1520-8559 0734-2101 |
| DOI: | 10.1116/1.572466 |
| Popis: | By extending earlier ideas and introducing new ones in this paper, we relate observable rf discharge parameters to the plasma etch characteristics of rate, selectivity, and anisotropy. The ion energy transport ‘‘ellipsoid’’ generated by the electric field across the plasma sheath is shown to induce anisotropic etch reactions and, under certain circumstances, to ‘‘enhance’’ the intrinsic chemical etch selectivity. The plasma sheath electric field is shown to be determined by observable rf discharge parameters. The rf discharge is reduced to an equivalent circuit, which relates the time averaged plasma body and sheath electric fields to the rf discharge parameters of plasma geometry, current or power and discharge excitation frequency. We find two regimes of excitation frequency, for otherwise identical conditions, generating much larger sheath electric fields below than above the ion plasma frequency (∼1 MHz). Fixing the plasma geometry and etch gas chemical composition is identified as central to obtaining simply behaved and reproducible etch characteristics. At comparable etch anisotropy, the only practical distinction between the etch characteristics of ‘‘high’’ pressure ‘‘plasma etching’’ and ‘‘low’’ pressure ‘‘reactive ion etching,’’ is that the former is capable of significantly higher etch rates and selectivities than the latter. |
| Databáze: | OpenAIRE |
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