KMP E3502 NEGATIVE PHOTORESIST FILMS ON SILICON

Abstract

Films of KMP E3502 negative photoresists with a thickness of 2.6–6.0 μm, deposited onto the surface of silicon wafers by centrifugation, were studied using the indentation method. Stabilizing treatment leads to uniform and homogeneous removal of residual solvent from the film. At the same time, the film becomes denser, which increases its strength and decreases its elastic-plastic properties; no significant change in the film homogeneity is observed. Also, the stabilizing treatment improves the adhesion of the KMP E3502 photoresist to the silicon substrate and leads to an increase in the microhardness values by ~ 1.5 times. After ion etching, a sharp increase in the heterogeneity of the photoresist film and strong structuring of the film surface are observed, with the appearance of a continuous array of irregularities with dimensions of ~ 10 μm. The microhardness values after ion etching increase by 2.2 times compared to the initial film, while an explosive increase (more than 200 times) in the dispersion of the distribution of microhardness values is observed. In ion-etched films, the distribution of microhardness values broadens significantly and deviates radically from Gaussian. This is due to the explosive nature of the evaporation of residual photoresist molecules, leading to "swelling" of the photoresist film.