PROTON-TRANSFER TO MELAMINE CROSS-LINKERS IN X-RAY CHEMICALLY AMPLIFIED NEGATIVE RESISTS STUDIED BY TIME-RESOLVED AND STEADY-STATE OPTICAL-ABSORPTION MEASUREMENT

Proton transfer to melamine crosslinkers has been analyzed in three X- ray chemically amplified (CA) negative resists. One is an in-house fab ricated resist composed of m-cresol novolac, 2,4,6-tris (trichlorometh yl)-1,3,5-triazine (TCT), and hexamethoxymethylmelamine (HMMM). The ot her two are commercially available resists: SAL-601 (Shipley Co.) and AZ-PN 100 (Hoechst Co.). The behavior of protons induced by X-ray expo sure was analyzed using both conventional steady-state optical absorpt ion spectroscopy and nanosecond time-resolved absorption spectroscopy (pulse radiolysis). The results indicate that the protons are transfer red from the proton adducts (acid precursors) of matrix polymers to th e melamine crosslinker in a very early step. This proton transfer was much faster than that from the proton adducts of matrix polymers to di ssolution inhibitors in CA positive resists.