Effects of exposure wavelength and surface preparation conditions on the generation of blister defects in organic insulator layer

Abstract

We report a new factor for blister formation on organic photoresist (PR) and an improvement of this process. We have studied blister formation from more different standpoints, such as processes and instrumentation, than did previous reports. Unexpectedly, we observed radical blister formation in an experiment that involved exposure without any ultraviolet (UV) filters. After a series of experiments, the data showed that the organic PR blister problem was most likely caused by the specific wavelength of the UV light field on exposure. Surface preparations using wet and dry treatments prior to coating a thin film of organic PR on silicon nitride (SiNx) glass wafer were studied. By comparing exposure to different spectra, both with and without a UV filter, we confirmed the key point of blister formation in case of the organic PR. Additionally, various treatments of SiNx prior to the coating of organic PR were primarily performed to improve organic PR adhesion to SiNx glass substrate.