Modelling vacuum ultraviolet photon penetration depth and C=O bond depletion in 193nm photoresist

摘要

Vacuum ultraviolet (VUV) photons are known to modify the bulk chemical composition of 193 nm photoresist, typically penetrating -100 nm and depleting carbon–oxygen bonds.Fourier transform infrared transmission measurements as a function of VUV photon fluence demonstrate that VUV-induced bond breaking occurs over a period of time. We present a model based on the idea that VUV photons initially deplete near-surface O-containing bonds,leading to deeper, subsequent penetration and more bond losses, until the remaining near-surface C–C bonds are able to absorb the incident radiation. Fitted model photoabsorption cross-sections compare well with the literature values.