Three versions of LEM interferometric cameras have been released by Horiba Jobin Yvon Ltd. The LEM, for use by OEMs, offers simple analog output. The LEM CT, for use by OEMs and for process monitoring in industrial R&D environments, includes full computer control powered by a recipe editor. The LEM PR, for volume production environments, offers automatic spot positioning via Cognex pattern recognition and advanced communication abilities. Each system includes a 670- or a 905-nm laser that, when mounted on a dry-etch process chamber with a direct top view of the wafer, generates a small laser spot on the sample surface.