| 摘要 |
A method and apparatus (110) for determining the endpoint (e.g., TC1) of an etching step in a plasma etching process (101) for use in semiconductor wafer manufacturing. In one embodiment, an optical bandpass filter (e.g., 1542) is used for detecting a wavelength of electromagnetic emissions from elements of a chlorine-argon plasma employed to etch a titanium nitride layer from a semiconductor wafer so as to achieve a more precise determination of the endpoint of the process step. In another embodiment, a plurality of wavelengths (e.g., 1541-1544) in the electromagnetic emissions from elements in the plasma are combined for even more precise determination of the endpoint of a process step. The emissions of interest may be from the same or different elements in the plasma which may be produced by the etching materials or by materials from the wafer being etched. |
