CO₂‐Based Dual‐Tone Resists for Electron Beam Lithography

Abstract

The increasing global environmental and energy crisis has urgently motivated the advancement of sustainable materials. Significant effort has been focused on developing new materials to replace the fossil‐based resists in the semiconductor industry based on greener sources such as ice, dry ice, small organic molecules, and proteins. Such resist materials, however, have yet to meet the stringent requirements of high sensitivity, high resolution, reliable repeatability, and good compatibility with the current protocols. To this end, CO2‐based polycarbonates (CO2‐PCs) obtained from the copolymerization of CO2 and epoxides are demonstrated as sustainable dual‐tone (positive & negative tone) resists for electron beam lithography. By adjusting the chemical structure, developing agent, and molecular weight, the CO2‐PCs present high sensitivities to electron beam (1.3/120 µC cm−2), narrow critical dimensions (29/58 nm), and moderate line edge roughness (4.6/26.7 nm) for negative and positive resists, respectively. A deep understanding of the exposure mechanism of CO2‐PC resists is provided on the basis of the Fourier transform infrared, Raman, and electron ionization mass spectroscopy. 2D photonic crystal devices are fabricated using the negative and positive CO2‐PC resists, respectively, and both devices show distinct colors derived from their well‐defined nanostructures, indicating the great practical potential of CO2‐derived electron beam resists.

Macrocycle Network-Aided Nanopatterning of Inorganic Resists on Silicon

“…We first studied the sensitivity of the present resist composition (NMeBTA) at different beam energies (Figure S15a). To advance our study on these resist compositions for their utilization in e-beam lithography (EBL), − a film of NMeBTA was spin-coated on a 2 × 2 cm 2 silicon wafer from its PGMEA solution, which was then exposed initially with e-beam (kinetic energy of e-beam was 10 keV). The corresponding dose array indicating the energy on each square has been shown in Figure S15b.…”

Sulfur-containing polymers derived from SO2: synthesis, properties, and applications

“…Due to easy and complete degradation under diverse stimuli, polysulfones can be used as sensitive positive resists for electron beam lithography, which have similar behaviors to CO 2 -based polycarbonates. 117 Bowden and Thompson found that polysulfones derived from different terminal olefins have similar degradation rates, 118 and the sensitivity was of the order of 1–2 × 10 −6 coulomb per cm 2 at 5 kV, determined in solution development. Interestingly, it was reported that polysulfones could also be etched in a vapor development process.…”

“…116 Due to easy and complete degradation under diverse stimuli, polysulfones can be used as sensitive positive resists for electron beam lithography, which have similar behaviors to CO 2 -based polycarbonates. 117 Bowden and Thompson found that polysulfones derived from different terminal olefins have…”

Modular Organoboron Catalysts Enable Transformations with Unprecedented Reactivity

“…We believe that a large pool of catalysts that exhibit diverse built-in reactivity will become accessible as their synthesis involves only the simple joining of amines, halohydrocarbons, and boranes; as a bonus, these components are generally commercially available on a large scale. The development of metal-residue-sensitive applications, such as elastomers, membranes, and lithography, will be promoted, benefiting from the continuous research on highly active metal-free boron catalysts. This Account should stimulate research on areas of other chemical conversions that are based mainly on the application of nucleophiles and electrophiles or Lewis acids and bases.…”