Submitted by Daniel Witte,
Stanford University
A silicon wafer is etched in KOH, with the assistance of a laser.
The beam locally heats the silicon, increasing the etch rate greatly.
The “fireworks” are small pieces of silicon breaking free and
dissolving in the KOH solution. Dark-field illumination brings out
the edge features.
Winner of the 2007 EIPBN Micrograph Contest Grand Prize.