| 摘要 |
An inventive method for optically detecting a trench depth in a wafer is disclosed. The method includes detecting a first maxima in the intensity of a multi-wavelength light source, a portion of the light being reflected from the top trench surface of a wafer. A second maxima is then detected in the intensity of the multi-wavelength light source, a portion of which being reflected from the bottom trench surface of a wafer. The method further includes determining a maxima peak difference between the first maxima and the second maxima, wherein the trench depth corresponds to the maxima peak separation. The invention provides a robust, cost effective method for trench depth detection.
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