Fluorine-functionalized Porous Organic Polymers for Durable F-gas Capture from Semiconductor Etching Exhaust

Efficiently capturing and recycling perfluorinated electron specialty gases (F-gases) with severe greenhouse effects (e.g., long atmospheric lifetime and high global warming potential) from etching exhaust is of great significance to the semiconductor industry. The adsorption separation technique based on a porous adsorbent is considered as an economical and effective method to remove the F-gases in the semiconductor exhaust, benefiting from its low energy consumption and high operational feasibility. Herein, two fluorinated microporous polymers (termed POPTrB-4F and POPTrB-8F) have been synthesized via direct C-H arylation polycondensation. Motivated by their fluorinated pore structure and sturdy covalent bond linkage mode, the separation performances of POPTrB-4F/8F for F-gases under both equilibrium and kinetic conditions were systematically studied. Both experimental results and theoretical calculations show that these two fluorinated polymers can selectively capture F-gases from the simulated etching exhaust. Impressively, the ideal adsorbed solution theory selectivity of POPTrB-4F and POPTrB-8F to SF₆ reached 62.88 and 51.55, respectively, at 298.15 K and 1 bar. Moreover, the mechanisms of gas adsorption and separation in porous organic polymers have also been profoundly revealed through simulation calculations based on the density functional theory. These results suggest the possibility of exploiting these fluorinated microporous polymers for the separation of F-gases in an eco-friendly way.