Low-Cost, High-Precision Method of Etching Semiconductors
Chip makers and semiconductor researchers need to precisely control the dimensions of their devices because they affect performance, speed, error rate, and time to failure. Semiconductors are commonly shaped by etching with chemicals but etching errors, such as residual layers, can affect the ability to further process and etch as well as hamper device performance. University of Illinois researchers have developed a low-cost method to carve delicate features onto semiconductor wafers using light. The new technique can monitor a semiconductor's surface as it is etched, in real time, with nanometer resolution. It uses a special type of microscope that uses two beams of light to very precisely measure topography. Because the new method is purely optical, there is no contact with the semiconductor surface and the researchers can monitor the whole wafer at once instead of point-by-point.