Solvent development processing of chemically amplified resists: chemistry, physics, and polymer science considerations

摘要

Solvent development of chemically amplified (CA), negative tone photoresists depends on several factors including molecular weight of the photoresist, the strength of polymer-solvent interactions, and the strength of polymer-polymer interactions in the undeveloped regions. Absent are the ionic interactions present in the aqueous base development of CA resists that greatly aids dissolution and image contrast. In its place, strong hydrogen bonding of the exposed photoresist leads to effective resistance to dissolution in non-polar developers. These effects are discussed in the context of Flory-Huggins theory. As part of a study of low environmental impact developers several, non-polar solvents have been investigated with negative tone, chemically amplified photoresists. These include supercritical CO2, hydrofluoroethers and silicone fluids. Each of these solvents has low surface energy, unique dissolution characteristics and is capable of developing sub-50 run patterns. Performance aspects of these developers will be described.