Effect of photoacid generator concentration and developer strength on the patterning capabilities of a model EUV photoresis

摘要

Current extreme ultraviolet (EUV) photoresist materials do not yet meet requirements on exposure-dose sensitivity, line-width roughness (LWR), and resolution. Fundamental studies are required to quantify the trade-offs in materials properties and processing steps for EUV photoresist-specific problems such as high photoacid generator (PAG) loadings and the use of very thin films. Furthermore, new processing strategies such as changes in the developer strength and composition may enable increased resolution. In this work, model photoresists are used to investigate the influence of PAG loading and developer strength on EUV lithographically printed images. Measurements of LWR and developed line-space patterns were performed to highlight a combined PAG loading and developer strength dependence that reduce LWR in a non-optimized photoresist.