The present invention discloses a technique of removing a substance from a
substrate surface, such as stripping photoresist from a wafer, or forming
a substance on a substrate surface. Substrates to be treated are parallel
arranged at an equal interval and are immersed in a liquid with only a
lower portion thereof being below the liquid surface. Gas such as ozone
is introduced into the liquid and is continuously bubbling below the
substrates. The bubbles will ascend between two adjacent substrates and
climb on the surfaces of the substrates before they burst. The liquid
boundary layers on the substrate surfaces are compressed and refreshed in
the course of a dragging ascent of the bubbles, enhancing mass transfer
between gas/liquid/solid substances across the liquid boundary layer,
thereby resulting in a fast reaction and a fast treatment of the surface
of the substrates.