US Patent 7494597 Method and apparatus for etching disk-like member

Disclosed are a method and apparatus for etching disk-shaped members, especially a method and apparatus for etching semiconductor wafers. In a method wherein wafers (30) are rotated and etched in an etching chamber (12) which is filled with an etching solution, a non-rotating cell plate (26) is disposed between two rotating wafers (30). In an etching apparatus wherein multiple wafers (30) are supported and rotated by a rod (16), the cell plate (26) is disposed between each two wafers (30). The cell plate (26) has a surface area roughly equivalent to that of the wafer (30).