Process for etching a wafer using an aqueous solution of sulfuric acid and hydrogen peroxide comprises removing a sample from a wafer processing tank, and comparing the concentration of hydrogen fluoride in the solution in the sample

摘要

Process for etching a wafer (8) using an aqueous solution of H2SO4 and H2O2 comprises removing a sample from a wafer processing tank (2) at regular intervals; comparing the concentration of HF in the solution in the sample using a comparing unit (9) with a reference value; and acquiring a concentration signal in a dosing pump (4) for the introduction of HF from an HF supply container (3) into the solution or a signal for exposing the wafer to cleaning. An Independent claim is also included for a device for etching a wafer. Preferred Features: Etching of the wafer is carried out in an immersion bath using an HF concentration of 5-50 ppm. The bath has a temperature of 20-60 deg C.