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Technological control over ultra-trace level contaminants is important for semiconductor development. Despite technological developments, defects remain in the single wafer wet cleaning process. In this paper, the source of the contamination is explained via trace analytical methods. Fluorine resin materials of polytetrafluoroethylene (PTFE) and ethylene tetrafluoroethylene (ETFE) are commonly used in semiconductor equipment. Isopropyl alcohol (IPA) oxidation reactions occur at high temperature below the boiling point due to impurities. IPA changed to different alcohol forms from gas chromatography (GCMS) analysis. The oxygen concentration in the X-ray photoelectron spectroscopy (XPS) results increased and formed new bonds in IPA with fluorine resin. These reactions confirmed that cations were a catalyst from the time-of-flight secondary ion mass spectrometry (TOF-SIMS) results. Representative ions were Fe+, K+, and Na+ with different concentrations for each material.

K3PO4 was found to effectively catalyze the carboxylation of amines by CO2, producing corresponding 1,3-disubstituted ureas in high yields and selectivities. X-ray diffraction and FT-IR spectroscopic analysis of the solid mixture, recovered from the carboxylation of n-butylamine, revealed that K3PO4 was completely transformed into KH2PO4 and KHCO3. Mechanistic and computational studies suggested that the high activity of K3PO4 could be attributed to the synergy effect exerted by the co-presence of KHCO3 and KH2PO4, generated from the interaction of K3PO4 with CO2 and water.

Three different types of nitrile-functionalized amines, including 3-( N , N -diethylamino)propionitrile (DEAPN), 3-( N , N -dibutylamino)propionitrile (DBAPN), and N -methyl -N , N -dipropionitrile amine (MADPN) were synthesized, and their SO 2 absorption performances were evaluated and compared with those of hydroxy-functionalized amines such as N , N -diethyl- N -ethanol amine (DEEA), N , N -dibutyl- N -ethanol amine (DBEA), and N -methyl- N , N -diethanol amine (MDEA). Absorption–desorption cycle experiments clearly demonstrate that the nitrile-functionalized amines are more efficient than the hydroxy-functionalized amines in terms of absorption rate and regenerability. Computational calculations with DBEA and DBAPN revealed that DBEA bearing a hydroxyethyl group chemically interacts with SO 2 through oxygen atom, forming an ionic compound with a covalently bound OSO 2 − group. On the contrary, DBAPN bearing a nitrile group physically interacts with SO 2 through the nitrogen and the hydrogen atoms of the two methylene groups adjacent to the amino and nitrile functionalities.

Despite the academic and industrial importance of the chemical reaction between carbon dioxide (CO(2)) and alkanolamine, the delicate and precise monitoring of the reaction dynamics by conventional one-dimensional (1D) spectroscopy is still challenging, due to the overlapped bands and the restricted static information. Herein, we report two-dimensional infrared correlation spectroscopy (2D IR COS) and principal component analysis (PCA) on the reaction dynamics of a sterically hindered amine, 2-[(1,1-dimethylethyl)amino]ethanol (TBAE) and CO(2). The formation of carbonate rather than carbamate species, which contribute to the unusual high working capacity of ∼1 mole CO(2) per mole of TBAE at 40 °C, occurs through deprotonation of the hydroxyl group, protonation on the nitrogen atom of the amino group, and formation of a carbonate species due to the steric hindrance of the tert-butyl group. In particular, PCA captures the chemical transition into a carbonate species and the main contributions of ν(CO(2)), ν(OH), ν(C - N), and ν(C=O) bands to the carbonation, while 2D IR COS verifies the interrelation of four bands and their changes. Therefore, these results provide a powerful analytic method to understand the complex and abnormal reaction dynamics as well as the rational design strategy for the CO(2) absorbents.