A novel spectroscopic approach to investigate transport processes in polymers: the case of water–epoxy system

Fourier transform infrared spectroscopy studies of water-polymer interactions in chemically amplified photoresists

“…3,5,11,[14][15][16][17]19 This peak at 2953 cm -1 is due to water molecules H-bonded onto specific polar sites along the polymer network. In the tBOC photoresist system, the OH group formed during the deprotection would be a good candidate for a strong H-bonding site.…”

“…The molar absorptivity significantly increases with the degree of hydrogen bonding, so the cross section would be different for each sub-band. 5,11,14 Therefore, we look only at the change in each fraction with humidity to see how the interaction inside the polymer network is affected when more water is present. The fraction of each type of water present depends on various chemical and physical…”

“…Among the physical changes that water can induce are plasticization, hygrothermal degradation, swelling, alteration of tensile strength and hardness, and change in net dielectric constant of a film. [2][3][4][5][6] Water can also affect chemical processes in polymers such as the deprotection reaction in photoresists used in the fabrication of electronic circuits. 2,7,8 Poly(t-butoxycarbonylstyrene) (tBOC) 9 and ketal-protected Poly(hydroxystyrene) (KRS-XE) 10 are two important chemically amplified photoresist systems.…”

“…3,5,[11][12][13][14][15][16] The vibrational spectrum can be measured in situ at a variety of humidities and provides details about the water-polymer interactions and hydrogen bonding. In this investigation, the molecular information obtained contributes to the understanding of transport through the polymer, which ultimately helps explain the deprotection reaction kinetics.…”

Infrared Spectroscopy - Materials Science, Engineering and Technology

“…Water deteriorates thermomechanical properties (Tg, modulus, yield strength, toughness...), and adhesion, it induces chemical degradation of the network and also generates stresses because of swelling (Nogueira et al, 2001;Cotugno et al, 2001;Blanco et al, 2006;Ji et al, 2006;Xiao & Shanahan, 2008). Significant efforts have been done to elucidate the interactions of water with epoxy/amine networks and the diffusion mechanisms operating during water uptake, and many different techniques have been used: from the fast and easy gravimetry to more complex techniques such as NMR spectroscopy (Zhou & Lucas 1999) or fluorescence (Mikes et al, 2003).…”