Texas Instruments Incorporated
Generating multi-focal defect maps using optical tools

Abstract:

A method comprises obtaining a wafer comprising a plurality of components, wherein each of the plurality of components exposes a first surface of the component present in a first focal plane and a second surface of the component present in a second focal plane. The method comprises generating, by an optical tool, a first image of the first surface and a second image of the second surface of one of the plurality of components. The method comprises comparing, by a processor, the first image with a first reference image to produce a first value and the second image with a second reference image to produce a second value. The method comprises generating, by the processor, a wafer map indicating a quality state of the one of the plurality of components based on the first and second values.