248nm PR

1. 248nm PR 193nm PR NSF GOALI: Interactions of Plasmas/Energetic Beams with Organic Masking Materials G. Oehrlein, D. Graves and E. Hudson DMR  - 0406120 Fig. 2: Photoresists suitable for short-wavelength PL (193 nm) require different polymer structures – e.g. no aromatic rings - than more traditional PL (248 nm), but show unacceptable surface/line edge roughness as a result of PE. Key Problem: What are the molecular design factors of photolithographic materials that are consistent with the transparency requirements of 193 nm PL and provide optimal etch and morphological stability during PE? Approach: We utilize specially synthesized/fully characterized model compounds based on different polymer backbones/functional groups to investigate etch and morphological stability in plasma/beam environment. Industrial Collaboration: Essential project feature: Interaction with key plasma etch (LRC) and photoresist (R&H EM) suppliers Fig 1: Fabrication of nanostructures using photolithography (PL)/plasma etch (PE) requires molecular level control/understanding of plasma-polymer interactions. HAMA Vs. HADA Fig. 3: Examples of model polymers synthesized at Rohm and Haas for this project and employed in plasma/beam studies at UMD/UCB.

2. NSF GOALI Interactions of Plasmas/Energetic Beams with Organic Masking Materials G. Oehrlein, D. Graves and E. HudsonDMR  - 0406120 Key Results/Insights • Processing of selected model polymers using realistic fluorocarbon plasma process suitable for nanoscale pattern transfer has for the first time established key differences in the degree and temporal dependence of nanoscale surface roughness formation as a function of polymer design. Examples are shown in Figs. 4 and 5. • Fig. 4 highlights the influence of H or CH3 termination of otherwise identical polymer structures on nanoscale surface roughness formation and can be related to fundamental polymer cross-linking/scissioning. • Fig. 5: Surface roughness formation has been correlated with surface chemistry evolution (expressed in terms of the fluorine/carbon ratio F/C) for the first time. Plasma-formed species can chemically transform the polymer surface and impede cross-linking reactions. • Comparisons of consequences of polymer processing in plasma environments (UMD) to well characterized ion/radical beam processing (UCB) are helping to clarify respective roles of ions, energy and reactive neutrals in surface and line edge roughness formation. • The composite of these results clarifies polymer design parameters that are prerequisite of controlling nanoscale roughness phenomena in plasma/polymer interactions during industrial processing Fig. 4: Temporal evolution of RMS surface roughness for the two model compounds along with AFM images Fig. 5: Correlation of surface roughness to surface chemical transformations (fluorination)

3. NSF GOALI Interactions of Plasmas/Energetic Beams with Organic Masking Materials G. Oehrlein, D. Graves and E. HudsonDMR  - 0406120 Education and Outreach: • This NSF GOALI project has enabled a unique multidisciplinary and strongly interactive/interdependent research environment for graduate and undergraduate students at both UMD and UCB • Monthly phone conferences/data sharing of university/industrial participants enable effective communication, deeper understanding of research results, planning of future research and providing a sense of “jointly we can change the world” • Lam Research graduate student summer internships for (hosted by Dr. Hudson) • Lab visits have been used to expand/improve collaboration of project participants – faculty have presented research results at both Lam Research Corp. (Aug. 2006) and Rohm & Haas Electronic Materials (Nov. 2005) • Communication of research results to worldwide community through local, regional and international meeting participation along with journal publication is ongoing Fig. 6: Undergradudate student Brian Smith performing ellipsometric measurement of PR at UMD. Fig. 7: Undergraduate student Anton Bashkirtsev demonstrates beam apparatus interface to graduate student Dustin Nest (UCB)