Transformation of the Spectra of a Attenuated Total Reflection when Drying a Diazoquinone-Novolach Photoresist

Abstract

The Fourier transform infrared spectroscopy of the attenuated total reflection (ATR), solutions and films of a positive diazoquinone-novolac (DN) FP9120 photoresist (PR) are investigated. The bands at 966, 1110, 1240, and 1735 cm^–1, caused by the absorption of the solvent 1-methoxy-2-propyl acetate (MPA), are dominant in the ATR spectra of the PR solution. The solvent is completely removed from the 1.0–5.0- μm-thick PR films during drying at temperatures of ~90°C for 1 hour. It is preferable to detect the residual solvent in solid PR films using the 966 cm^–1 band. The intensity of the vibrations related to aromatic rings (bands in the range 1510–1610 cm^–1) increases after drying. The band at 1452 cm^–1 is due to the valent vibrations related to the CH2 bridge between the aromatic rings of phenol-formaldehyde resin and after drying it splits into 2 bands.