Real-Time Etching Topography (image) University of Illinois at Urbana-Champaign Caption This is a three-dimensional image of the University of Illinois logo etched into a gallium-arsenide semiconductor, taken during etching with a new microscopy technique that monitors the etching process on the nanometer scale. The height difference between the orange and purple regions is approximately 250 nanometers. Credit Chris Edwards, Amir Arbabi, Gabriel Popescu, and Lynford Goddard Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.