Etching apparatus and etching method thereof

An etching apparatus, comprising:

• an etching device, performing an etching process on a material to be processed to form a feature structure, and the material to be processed comprises a material layer and at least one mask layer formed on the material layer, wherein the etching device comprises:
• an end point detector, detecting a light intensity at a specific wavelength for light generated when the etching process is performed on the mask layer to be processed and generating an end point detection signal;
• and
• a control device, coupled to the etching device and determining an etching completion time of the mask layer to be etched according to the end point detection signal, calculating a thickness of the mask layer to be etched according to the etching completion time, and adjusting an etching time of the material layer according to the thickness of the mask layer to be etched, wherein the etching process is performed on the material layer after adjusting the etching time of the material layer.