The first method for making such V-shaped slits is very simple and inexpensive. It uses only low-resolution photolithography and wet etching so avoiding the use of more labor intensive fabrication techniques. These slits can be used as transmission electron microscope (TEM) substrates and are particularly useful for combining TEM imaging and electrical transport measurements as demonstrated with a multi-walled carbon nanotube (MWNT).
In the second method of slit making, the final wet-etching step is replaced by focused ion beam (FIB) milling. While more labor intensive than the first method, the resulting higher stability allows the combined TEM imaging and cryogenic measurement of more fragile samples, such as superconducting nanowires.
Nanostencil deposition
The team has demonstrated how these slits can be used to form nanowires. Called nanostencil deposition, the slit is pressed against a substrate covering the entire substrate except for the area of the slit. When metal is deposited, only the open area of the substrate receives metal, thereby forming a nanowire. The unique design of the slit allows one-step fabrication of a nanowire seamlessly connected to contact leads by this process. Other future applications for these types of slits might be nano-nozzles or in near-field optics.
The researchers presented their work in Nanotechnology.