Apparatus for etching wafer

摘要

According to the invention, a plurality of wafers are disposed in a steady-state rotating flow of a mixed acid in a main chemical processing zone in an etching trough, the rotating flow being formed to be substantially concentric circle with the wafers, thus permitting uniform dispersion of air bubbles for bubbling in the mixed acid and stable flow thereof to obtain reliable reproduction of satisfactory flatness and luster. A flow of mixed acid in the etching trough is formed as a superficial horizontal laminar flow in the neighborhood of the liquid level and a rotating flow induced in the neighborhood of the semiconductor wafer. Mixed acid in the etching trough is caused to overflow from the mixed acid supply side to the opposite side and is thus discharged.