A confocal microscope is a profile measurement tool with the following 3 features:

A confocal microscope detects reflected light from a sample with a photodetector for measurement. Because it is an optical method, it performs non-contact, non-destructive measurement. It can perform measurement on a sample having any type of topography as long as light is reflected by the sample and received by the photodetector. For example, a confocal microscope can perform measurement on deep and narrow trenches or holes, the inside of which the probe of a contact-type profiling tool cannot reach. A confocal microscope can also perform measurement on a soft sample without causing any damage because it is a non-contact method. Unlike a scanning electron microscope, a confocal microscope requires no sample preparation such as deposition and evacuation, and it can be used in an atmospheric environment.

The optics of a confocal microscope (confocal optics) provide high-resolution, high-contrast images free from the interference of scattered light from outside the focal plane. They can create an all-in-focus image showing all points clearly focused throughout the field of view. The confocal optics form a clear picture even if the sample has an uneven surface.

A confocal microscope can capture height information at all points (pixels) in the field of view. Thanks to this capability, it can measure 3D topographic features including height changes, widths, surface roughness, and film thickness.