Measurement of hydroxyl radicals in wafer cleaning solutions irradiated with megasonic waves

Effect of sound frequency and initial concentration on the sonochemical degradation of perfluorooctane sulfonate (PFOS)

“…The formation of • OH is directly dependent on the number of cavitation events [26]. As expected from the PFOS degradation experiments, the • OH concentration increased with increasing sound frequency (Fig.…”

“…Samples were collected in regular time intervals and analyzed for • OH using fluorescence spectroscopy. The technique is based on capture of • OH by terephthalic acid to form 2-hydroxyterephthalic acid [26,27]. When excited under a wavelength of 318 nm, 2-hydroxyterephthalic acid undergoes emission at 425 nm.…”

Analysis of Sonoluminescence Signal from Megasonic Irradiated Gas-Containing Aqueous Solutions Using Replaceable Single-Band Filters

“…An area of interest to researchers involved in sonic cleaning techniques is a correlation between SL signal and hydroxyl radical concentration in ammonia solutions that are used for surface cleaning in semiconductor industries. 30 Very recently, using a fluorescence technique that works on the capture of hydroxyl radicals (OH • ) by terephthalic acid, Keswani et al 31 reported the generation rate of these radicals (∼ 0 to 0.2 μM/min) in ammonium hydroxide solutions irradiated with megasonic waves. The generation rate of OH • decreased from ∼ 0.16 μM/min to ∼ 0.005 μM/min as ammonia concentra-tion increased from 0.001% to 1% (in volume).…”

Use of a Simple Cavitation Cell Set-Up with Replaceable Single Band Filters for Analysis of Sonoluminescence Signal from Megasonic Irradiated Gasified Aqueous Solutions

“…Very recently, using a fluorescence technique that works on the capture of hydroxyl radicals (OH  ) by terephthalic acid, Keswani et al (21) reported the generation rate of these radicals (~ 0 to 0.2 M/min) in ammonium hydroxide solutions irradiated with megasonic waves. The generation rate of OH  decreased from ~ 0.16 µM/min to ~ 0.005 µM/min as ammonia concentration increased from 0.001% to 1% (in volume).…”

“…An area of interest to researchers involved in sonic cleaning techniques is correlation between SL signal and hydroxyl radical concentration in ammoniacal solutions that are used for cleaning. Very recently, using a fluorescence technique that works on the capture of hydroxyl radicals (OH  ) by terephthalic acid, Keswani et al (21) generation rate of these radicals (~ 0 to 0.2 M/min) in ammonium hydroxide solutions irradiated with megasonic waves. The generation rate of OH  decreased from ~ 0.16 µM/min to ~ 0.005 µM/min as ammonia concentration increased from 0.001% to 1% (in volume).…”