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Abstract Ion bombardment of photoresist materials during plasma etching results in the formation of a surface dense amorphous carbon (DAC) layer that contributes to both etch resistance and the development of surface roughness. Real‐time ellipsometric measurements/analysis reveals that a C4F8‐containing plasma interacts with an Ar‐plasma‐formed DAC layer to produce a modified DAC/fluorocarbon (FC) layer by FC deposition/diffusion of fluorine into the surface. The depletion of the DAC layer via modification and ion bombardment causes the etch rate of the bulk layer to increase. As the modified surface layer is formed, a noticeable decrease in surface roughness decrease is observed. These findings provide an understanding of the mechanisms of atomic layer etching processes in photoresist materials.
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Validation of etching model of polypropylene layers exposed to argon plasmas
Abstract Thin layers of polypropylene (PP) have been treated by argon low‐temperature plasmas in an inductively coupled plasma setup. The etched thickness of PP was monitored in situ by means of single‐wavelength ellipsometry. The ellipsometric model of the polymer surface exposed to plasma consists of a UV‐modified layer, a dense amorphous carbon layer because of ion bombardment, and an effective medium approximation layer, which accounts for moderate surface roughness. The etching behavior has been compared to a model based on argon ion beam irradiation experiments. In this approach, surface processes are described in terms of etching yields and crosslinking probabilities as a function of incident fluxes and energies of Ar ions and UV photons. The ion beam model fits well with the plasma etching results.
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- Award ID(s):
- 1449309
- PAR ID:
- 10089362
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Plasma Processes and Polymers
- Volume:
- 16
- Issue:
- 6
- ISSN:
- 1612-8850
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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