3D-microscopy with large depth of field

We introduce a simple attachment to a common microscope enabling it to measure the microtopography of both rough and smooth samples and thus combining the inherent high lateral resolution of the microscope and depth information. We achieve a depth resolution better than 10 nanometers and a depth of field more than 100 times the Rayleigh depth. Even steep slopes of more than 60 degrees become accessible (dependent on the aperture). The method is derived from 'Phase measuring micro-deflectometry' which is a novel tool to measure the slope of reflective structures on a microscopic scale. With the microscopic lateral resolution and the very large depth of field, as well as a low noise level, the images display 'SEM-like' features.