Photoresist stripping using novel sulfuric/ozone process

Sulfuric acid (H₂SO₄) and ozone (O₃ ) mixture process (SOM) with in-situ concentration monitor for O ₃ and peroxyso-di-sulfuric acid (H₂S₂O ₈) was developed Ultraviolet spectrometers with 190-200 nm and 254 nm of wavelength were used to detect H₂S₂O ₈ and O₃ dissolved in SOM, respectively. In order to mix H₂SO₄ and O₃ effectively, the O ₃ gas ejectors were jointed to a quartz bath directly. Using SOM process with UV oxidant monitors and O₃ gas ejectors, heavily dosed resist and dry etched resist could be removed perfectly without dry ashing process