Semiconductor etch without the sketch

To craft some of the most complex semiconductors, manufacturers etch pre-defined patterns into wafers, carving out structures layer by layer. The processes can be time-consuming and are executed blindly, leaving few opportunities to monitor the etching or make any necessary adjustments.

Now, researchers at the University of Illinois at Urbana-Champaign have developed a technique to watch and control the etching of semiconductors as it is happening, with a height resolution at the scale of nanometres - billionths of a metre.

The researchers describe the technique in the 28 September 2012, issue of Light: Science & Applications, an open-access, peer-reviewed publication from the Nature Publishing Group.

In that paper, the researchers explain how they combined real-time observations from epi-illumination diffraction phase microscopy (epi-DPM) with photochemical etching techniques to manufacture gallium arsenide micro-lenses as a proof-of-concept for the techniques. Read the article.