Embedded silicon carbide “replicas” patterned by rapid thermal processing of DNA origami on silicon

When deoxyribose nucleic acid (DNA) origami on silicon substrates are heated above 900 °C, the carbon atoms from the DNA diffuse several nanometers into the silicon to form embedded silicon carbide (SiC) nanostructures. Atomic force microscopy and scanning electron microscopy images show that the SiC structures retain the shape and lateral dimensions of the original DNA origami structures, and the SiC material resists etching by hydrofluoric acid. X-ray photoelectron spectroscopy depth profiling shows a SiC peak present at depths of up to ∼15 nm. This process is a mask-free technique for patterning SiC on silicon for possible nanoelectronic applications.