METHOD OF CONTROLLING METALLIC LAYER ETCHING PROCESS AND REGENERATING ETCHANT FOR METALLIC LAYER ETCHING PROCESS BASED ON NEAR INFRARED SPECTROMETER

摘要

In a method of controlling a metallic layer etching process for fabricating a semiconductor device or a liquid crystal display device, the composition of the etchant used in etching the metallic layer is first analyzed with the NIR spectrometer. The state of the etchant is then determined by comparing the analyzed composition with the reference composition. In case the life span of the etchant comes to an end, the etchant is replaced with a new etchant. By contrast, in case the life span of the etchant is left over, the etchant is delivered to the next metallic layer etching process. This analysis technique may be applied to the etchant regenerating process in a similar way.