Supercritical-Carbon-Dioxide Solubility Characteristics of Polyphenols and Polyphenol Derivatives

Acid-Labile, Chain-Scission Polymer Systems Used as Positive-Tone Photoresists Developable in Supercritical CO2

“…Small molecules with up to two hydroxyl functionalities also possess some solubility in scCO 2 , suggesting that monomers based on bisphenol platforms can be soluble in scCO 2 . This has also been confirmed by other researchers . It has been shown that bisphenol monomers can be polymerized simply using acid-labile acetal linkers .…”

Supercritical Fluids for the Fabrication of Semiconductor Devices: Emerging or Missed Opportunities?

“…Shiraishi and co-workers reported the solubility of several protected and deprotected polyphenols in CO 2 to demonstrate the development concept. 103 Ober demonstrated high resolution patterning using CO 2 -developable MG resists including calix [4]resorcinarene derivatives. 104,105 The structure of sev- line edge roughness was observed.…”

“…In the case of a supercritical CO 2 -based medium, the protected MG is soluble in the fluid, whereas the deprotected MG is much less soluble. Shiraishi and co-workers reported the solubility of several protected and deprotected polyphenols in CO 2 to demonstrate the development concept . Ober demonstrated high resolution patterning using CO 2 -developable MG resists including calix[4]resorcinarene derivatives. , The structure of several resists and images of the films following e-beam patterning and CO 2 development are shown in Figure .…”

Dissolution phenomena of phenolic molecular glass photoresist films in supercritical CO2

“…Due to excessive plasticization of these particular molecular glass resist films under scCO2, using them to form stable, high-fidelity patterns remains a challenge. As a result of their uncross-linked nature, flow and pattern distortion happens 19 From the molecular glasses reported in this paper, hxph-mp-tboc has been reliably patterned and developed without the assistance of cross-linking. The resulting pattern is shown in Fig.…”

“…17,18 However, most experimental studies have explored bulk solubility, which does not take into account any kinetic effects of film dissolution. 19 Studies that have explored film solubility have been mostly qualitative, which still leaves open questions about structure-property relationships of molecular glass architecture and their effect on dissolution kinetics. This study will make use of an interferometry-based dissolution-rate monitor, built in-house and reported previously.…”