KLA Corporation
Combined Transmitted and Reflected Light Imaging of Internal Cracks in Semiconductor Devices

Abstract:

A first light source is directed at an outer surface of a workpiece in an inspection module. The light from the first light source that is reflected from the outer surface of the workpiece is directed to the camera via a first pathway. The light from the first light source transmitted through the workpiece is directed to the camera via a second pathway. A second light source is directed at the outer surface of the workpiece 180.degree. from that of the first light source. The light from the second light source that is reflected from the outer surface of the workpiece is directed to the camera via the second pathway. The light from the second light source transmitted through the workpiece is directed to the camera via the first pathway.