Wafer inspection is an integral part of wafer manufacturing that ensures that the wafer is functional throughout its manufacturing. The task of inspecting wafers becomes more and more challenging as the designs continue to decrease in size. The smaller features can require a 50x objective lens magnification as well as ultra high-resolution accuracy and repeatability.

Patterns are exposed onto a wafer due to exposure tools lick scanners and require inspection after each exposure to ensure that the required design accuracy is achieved. There are many different devices that can be used in order to find defects depending on the overall wafer.

Wafer inspection is important in finding defects and problems with the wafer before manufacturing the final product. Patterned product wafers – wafers with an imprinted circuit pattern – require defects to be found in the deep sub-micron range of their imprints. Patterned wafer inspection technology is just one of the possibilities for wafer inspection.

Patterned wafer inspection uses white light as well as lasers to brighten the surface of the wafer. The images reflected in from the wafer’s surface features are collected and fed through a powerful image processing system. This machine then identifies the defects so that they can be eliminated.

Auto macro inspection technology is another type of inspection procedure intended for bigger scale particles. It does not require high magnification optics as it not meant for individual pattern inspection. It works similarly to patterned wafer inspection as it captures the details of defects using light illumination but differs in the fact that it captures all of the critical defects throughout the wafer with a single image.