The cliffs of fluffiness! Lashed by impossibly pointy nano-waves.
The fluffy stuff at the top is actually photoresist, a glassy substance that we use to protect semiconductor from plasma bombardment when we’re doing our etching. Here, the photoresist protected the semiconductor below it from being etched away, making the cliff, but in the process the photoresist took a pummeling from the ions, and ended up in this torn-up, fluffy state. The etching didn’t work cleanly; there should have been an abrupt transition between cliff and sea.
For a sense of scale, this cliff’s 2 micrometer height is about 1/50 the thickness of a sheet of printer paper.
This image was taken by my labmate Qing Gu, who just successfully defended her PhD thesis this week. Congratulations, Qing!