Silicon cracks could make a lab-on-a-chip

[Nipuna]

SOMETIMES you need to break things to fix them. South Korean researchers have developed a way of controlling patterns of cracks in silicon chips to create atomic-scale features such as nano-channels.

Koo Hyun Nam of Ewha Womans University in Seoul and colleagues etched a pattern of notches into a silicon wafer and deposited a layer of silicon nitride on top. The notches set up stresses within the nitride layer that cause it to crack in line with the underlying wafer's crystal structure, which acts as a guide (Nature, DOI: 10.1038/nature11002).

Nam says the nano-cracks could serve as channels for lab-on-a-chip type applications such as single-molecule sensing. Electron beams are currently used to etch atomic-scale patterns, but this is time-consuming and expensive. By contrast, cracks form instantaneously, says Nam.