Patent Number: 6,167,148

Title: Method and system for inspecting the surface of a wafer

Abstract: An improved wafer surface inspection system is disclosed. In one embodiment, the object surface inspection system includes a translation stage that generates relative motion between an object viewing device such as an objective lens and the surface of the object being inspected. A translation stage controller controls the relative movement of the object surface and the object viewing device. The translation stage controller determines current coordinates for the object surface and the object viewing device, compares the current coordinates to target coordinates generated by a processor, and generates a trigger signal in response to a match between the current coordinates to the target coordinates. A camera receives an image through the object viewing device and captures the image in response to the trigger signal while the translation stage generates relative motion between the object surface and the object viewing device. In accordance with the present invention, a white light image of an entire wafer surface may be obtained quickly and efficiently. Image processing software may then be used to identify solder bumps on the wafer surface and calculate parameters of the solder bumps. Quality control criteria may be automatically applied to the solder bump parameters to determine the suitability of the wafer for further processing, and to identify problems in wafer processing.

Inventors: Calitz; Louis D. (Los Gatos, CA), Du; Kexing Cecilia (Mountain View, CA), Norton; M. Kent (Los Gatos, CA), Worster; Bruce W. (Saratoga, CA)

Assignee: Ultrapointe Corporation

International Classification: G01N 21/95 (20060101); G01N 21/956 (20060101); G01N 21/88 (20060101); G06K 009/00 ()

Expiration Date: 12/26/2017