Wafer inspection system including a laser triangulation sensor

Abstract

One example of an inspection system includes a laser, a magnification changer, and a first camera. The laser projects a line onto a wafer to be inspected. The magnification changer includes a plurality of selectable lenses of different magnification. The first camera images the line projected onto the wafer and outputs three-dimensional line data indicating the height of features of the wafer. Each lens of the magnification changer provides the same nominal focal plane position of the first camera with respect to the wafer.

What is claimed is: 
     
         1 . An inspection system comprising:
 a stage for supporting a wafer to be inspected;   a laser line generator configured and arranged relative to the stage to project a laser line onto the wafer; and   a camera system arranged relative to the stage to image the laser line as reflected from the wafer, wherein the camera system is configured to:
 acquire two-dimensional images of the reflected laser line, 
 convert the two-dimensional images into three-dimensional lines formatted to indicate a height of features of the wafer, and 
 output the three-dimensional lines to indicate the height of features of the wafer.