Synthesis of End-Cap Enabled Self-Immolative Photoresists For Extreme Ultraviolet Lithography

Abstract

Manipulation. All reactions were carried out using a standard glovebox or Schlenk techniques under nitrogen or argon gas.All polymerization reactions were performed using Schlenk techniques with reaction temperature controlled by dry ice/acetone bath. All silicon wafers were cleaned by hot Piranha solution before coating.

Atomistic Modeling Approach for Predicting Association of Photoacid Generators in Extreme Ultraviolet Polymeric Photoresists

“…Unless stated otherwise, all simulations with homopolymers and copolymers consist of 70 molecules of 12-mer polymer chains. The chosen length of the polymer was similar to the average length used in experiments ,, and simulations. ,, Figure S2 shows the simulated polymer chain structures in this work. In all the bulk homopolymer and copolymer simulations, the end-to-end distance between the terminal backbone carbon atoms of the chains is within 20–23 Å which is less than half the simulation box length that ranges between 58 and 60 Å.…”

“…Unless stated otherwise, all simulations with homopolymers and copolymers consist of 70 molecules of 12-mer polymer chains. The chosen length of the polymer was similar to the average length used in experiments 26,40,41 and simulations. 15,18,42 Figure S2 shows the simulated polymer chain structures in this work.…”

“…The PAG candidates chosen for this study are ionic PAGs containing triphenyl sulfonium (TPS) cation with trifluoromethanesulfonate (TFMeS), nonafluorobutanesulfonate (NFBuS), perfluorophenyl sulfonate (PFPS), and adamantyltetrafluoroethyl sulfonate (ATFEtS) anions and nonionic naphthalimide sulfonate PAG (see Figure c). The selected polymer and PAG chemistries are representative of commercially available chemically amplified resists and of recent studies focused on the complex reactions occurring in photoresists exposed to EUV radiation. ,,− By choosing the PAG chemistries mentioned above, with their varying steric and ionic interactions, we are able to assess their effect on the interplay between PAG–PAG and polymer–PAG interactions.…”

Modular Synthesis of Phthalaldehyde Derivatives Enabling Access to Photoacid Generator-Bound Self-Immolative Polymer Resists with Next-Generation Photolithographic Properties

“…Our attempt to further improve this resist system by eliminating PAGs and relying only on the scission of a radiation responsive end-cap to initiate depolymerization was moderately successful as the photospeed of the material reached 90 mJ/cm 2 . 51 Rather than further pursue a PAG-free strategy, we reasoned that functionalizing a PPA monomer with different non-ionic PAGs would enable us to take advantage of the roughness reduction witnessed in many polymer-bound PAG resists (Figure 1). This reduction could also enable high sensitivity and contrast due to a dual amplification mechanism through use of non-ionic PAGs.…”

“…Recently, we reported the synthesis of a thermally stable brominated PPA resist with extremely low levels of outgassing. − This polymer was blended with novel PAGs and achieved sensitivities as low as 12 mJ/cm 2 under EUV radiation. Our attempt to further improve this resist system by eliminating PAGs and relying only on the scission of a radiation responsive end-cap to initiate depolymerization was moderately successful as the photospeed of the material reached 90 mJ/cm 2 . Rather than further pursue a PAG-free strategy, we reasoned that functionalizing a PPA monomer with different non-ionic PAGs would enable us to take advantage of the roughness reduction witnessed in many polymer-bound PAG resists (Figure ).…”