MAMA. NSF GOALI Interactions of Plasmas/Energetic Beams with Organic Masking Materials G. Oehrlein, D. Graves and E. Hudson DMR - 0406120. Model Compound Approach:
Model Compound Approach:
Study impact of different polymer backbones/endgroups on etch and morphological stability in plasma/beam environment to identify molecular design factors required for etch and morphological stability
Fig 1: Simplified schematic of problem of fabricating
nanosctructures using organic imaging materials
and plasma etch for pattern transfer.
Fig. 3: Chemical structure of one model compound employed in this work, with special functional groups marked.
Fig. 2: Resists after plasma etch showing
surface/line edge roughness incompatible
with nanoscale manufacturing
Completely Formulated Photoresists
We investigate the interaction of well characterized and controlled plasmas and energetic particle beams with completely specified and flexible model compounds as well as fully developed photoresist systems to establish the key factors that give rise to surface and line edge roughening for nanoscale patterning.
Figs. 4 and 5 show changes of the optical properties and surface roughness of photoresist systems/model compounds upon plasma exposure. All materials show modifications after a few seconds of exposure consisting of densification followed by surface roughening. Introduction of surface roughness depends strongly on the nature of the polymer backbone/ endgroups.
248 nm photoresist
RMS = 4.5 nm
After 60 s exposure
193 nm photoresist
RMS = 11.5 nm
After 60 s exposure
Fig. 4: Refractive index evolution for photoresist systems
during 60 s of plasma exposure and AFM images after 60 s.
Fig. 5: Refractive index and AFM roughness evolution for one model compound.
A first insight from comparison
of different model compounds:
Acrylate content (Fig. 6) improves plasma stability
Fig. 6: Chemical structure of compound YB-27C used for Fig. 5.
not an optimized process
Fig. 7: SEM image of compound YB-27B after ~60s of dielectric etch processing in a commercial reactor.
Fig. 8: Normalized FT-IR spectra of C-H stretch region for compound YB-27C after 1 and 2 min. exposure to dielectric etch processing in a commercial reactor.
NSF GOALI Interactions of Plasmas/Energetic Beams with Organic Masking Materials G. Oehrlein, D. Graves and E. Hudson DMR - 0406120
Photograph on Top: Graduate student Sebastian Engelmann discusses with undergraduate students Brian Smith and Michael Figueroa – all Materials Science and Engineering, University of Maryland, College Park - results that he has obtained in his research. Brian Smith and Michael Figuero began participating in the NSF funded research in 2005, and plan to actively contribute to the research on this topic during the final two years of their undergraduate program.
Photograph at Left: Graduate student Sebastian Engelmann working on an ultra-high vacuum surface analysis system used to characterize organic masking materials after plasma processing, while undergraduate student Brian Smith watches.