Supercritical fluid technology is proposed as a solventless technique for photoresist developing, a crucial step in semiconductor manufacturing. The concept exploits the pressure dependent solubility characteristics of dense gases, specifically carbon dioxide, for selectively dissolving the soluble portions of the exposed resist. Preliminary testing was conducted to demonstrate proof-of-concept; the results were remarkably successful and are described in this proposal. It is the objective of this effort to develop a dry process for use with at least one specific photoresist and to demonstrate that the process is applicable to both positive and negative bilayer and single layer resist systems. IBM Almaden Research Center will under subcontract provide the analytical, technical, and business expertise relating to photoresist chemistry and, generally, to integrated circuit manufacturing operations. In addition, through their relationship with MIT Lincoln Laboratory, IBM will have access to state of the art etching equipment. The advantages of utilizing supercritical carbon dioxide instead of solvents will have important ramifications on environmental issues, especially in minimizing waste generation and disposal. Furthermore, the technology offers the potential for processing several high performance resist systems that have been abandoned due to problems associated with conventional liquid organic solvent developers. Anticipated
Benefits: Aside from the environmental advantages over solvent processes, supercritical carbon dioxide developing of photoresists will significantly broaden the range of usefulness of existing resist systems and promises the potential for bringing to the market a host of chemically modified high performance resists systems which are not currently available. It is anticipated that as restrictions on solvent use become more stringent, this technology will proliferate into diverse areas of industry.
