Monitoring etching of semiconductor substrate, for use in semiconductor devices, by measuring time-dependent concentration pattern for representative etching chemical

摘要

A method for monitoring the etching of a semiconductor substrate (1), before a coating stage, involves measuring the time-dependent concentration pattern for representative etching chemical(s) (9) in the etching solution (2), then evaluating the actual state of the etching process from the measured signal. An independent claim is included for apparatus for carrying out the process, comprising (a) an infrared spectrometer (5) for analyzing the time-dependent concentration pattern in the washing products from the etching solution (2) and (b) an evaluation unit (6) for generating an etching process control signal (8) on the basis of the measurement results.