Etching behavior of an epoxy film in O2/CF4 plasmas
| Autor: | Frank D. Egitto, Luis J. Matienzo, F. Emmi |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
chemistry.chemical_classification
Diglycidyl ether Materials science Surfaces and Interfaces Polymer Epoxy Polyethylene Condensed Matter Physics Surfaces Coatings and Films chemistry.chemical_compound chemistry Chemical engineering Etching (microfabrication) visual_art Polymer chemistry visual_art.visual_art_medium Surface modification Reactive-ion etching Polyimide |
| Zdroj: | Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films. 9:786-789 |
| ISSN: | 1520-8559 0734-2101 |
| DOI: | 10.1116/1.577362 |
| Popis: | Epoxy polymers are commonly used in microelectronic packaging for printed circuit board fabrication. Exposure to plasma environments occurs during processing for purposes such as drill smear removal, surface modification, and decapsulation. In this investigation, epoxy films made from a brominated diglycidyl ether of bisphenol‐A, containing aliphatic and aromatic segments, were etched in a radio‐frequency plasma using a planar diode configuration. Etching rates were measured at various compositions of O2 and CF4 in the gas feed. Surface composition of etched and nonetched films were compared using x‐ray photoelectron spectroscopy. Comparison of etching behavior and fluorine surface coverage is made with polymers, which are either aliphatic or aromatic. Maxima in etching rates for polyimide, epoxy, and polyethylene films occurred at 22.5%, 35%, and 37.5% CF4 in O2, respectively. Fluorine atom surface coverage was 10%, 20%, and 2%, respectively, under these conditions. It is proposed that the low affinity for fluorine atoms of the aliphatic moieties in the epoxy drives the O2/CF4 gas feed mixture, which yields maximum etching rates toward higher CF4 concentrations, similar to observations made for fully saturated polymers like polyethylene. As a consequence, the aromatic epoxy segments become more heavily fluorinated as occurs for highly aromatic polymers, like polyimide, in fluorine‐rich plasmas. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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