Chemical Factors in the Degradation and Selective Dissolution of Methacrylate-Based Electron Beam Resist Polymers: A Nuclear Magnetic Resonance and Electron Spin Resonance Study.
Abstract
The dissolution of selected electron-beam resist polymers was studied by wide-line-NMR/Dynamic Nuclear Polarization signal enhancement techniques under experimentally restrictive conditions. It was demonstrated that d(6) -acetone is suitable for NMR-based dissolution studies, and that the amount of polymer required for a dissolution experiment can be reduced by a factor of ten (to 0.2 g) by selection of novel radical spin polarization materials. Studies of scarce experimental or irradiated polymers are now more feasible. The beneficial effects of carboxylate- and halocarbon substituents on the dissolution properties of methacrylate resists were demonstrated. An attempt was made to investigate the effect of various parameters on dissolution properties in acetone slurry (irradiation, molecular weight, molecular weight distribution, polymer surface characteristics or morphology), but in the unstirred environment of the experimental set-up, dissolution properties consistently ran counter to those expected from dissolution theory for well-mixed systems. The existence of a gel barrier to dissolution was not only inferred from the dissolution experiments, but also could be confirmed visually in selected samples. The gel barrier phenomenon may affect dissolution behavior inside the freshly-cut channels of the resist, where convection would be least effective. In other dissolution experiments, it was demonstrated that the sensitivity of the instrumentation is not sufficient to make 19-F NMR an acceptable alternative to 1-HNMR in dissolution studies of fluoropolymers. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1981
- Accession Number
- ADA098457
Entities
People
- Burkhard E. Wagner
Organizations
- United States Army Communications-Electronics Command