| 摘要 |
PURPOSE:To enable to maintain the uniform etching quantity irrelevant to the history thereof by a method wherein the etching hours to be performed by the etching liquid is calculated based upon the etching speed, and dipping work into a treatment tank and conveying work up to a washing tank are performed by a conveying mechanism according to the calculated etching hours. CONSTITUTION:A semiconductor b to monitor progress of etching is put in the treatment tank, laser rays are projected on the semiconductor wafer b for monitoring thereof, reflected light thereof is injected to a photodetecting part 14, and after converted into an electric signal, it is inputted into an arithmetic and control part 16, the etching speed of the semiconductor wafer for monitoring is operated at the arithmetic and control part thereof according to the electric signal mentioned above, and moreover the etching hours is operated according to film thickness of oxide films of previously inputted actual semiconductor wafers (a) and to the etching speed of the semiconductor wafer for monitoring mentioned above, and the conveying mechanism 2 is operated according to the operated etching hours thereof. |
