ETCHING DEVICE

PURPOSE:To uniformly form the etched surface in a semiconductor substrate as well as to secure the stabilized quality of product by a method wherein an etching process is performed in such a manner that the environments of an etching treatment vessel is decompressed from ordinary atmospheric pressure using a decompression vessel and a vacuum pump. CONSTITUTION:A treatment vessel 20, wherein a treatment liquid of phosphoric acid is filled, is provided on the etching device, and a heater 21 is provided at the bottom part of said treatment vessel 20. The electromotive force generating in the treatment liquid 11 is detected by the electrode 22a provided at a side part in the treatment liquid 11 and the clip type electrode 22b which is fixed at the upper end of the wafer 14 on a carrying container 15 located at the farther most part from the electrode 22a. The treatment vessel 20 is provided in a decompressed vessel 23. When an etching process is performed in a decompressed state, the bubbles generated by the chemical reaction between aluminum and phosphoric acid disappears soon, and the progress of treatment can be grasped by the signal sent from the electrodes 22a and 22b.