Nanofabrication using liquid helium films

We propose here a technique for precision deposition of single atoms or ordered arrays of atoms onto a substrate by first suspending the atoms as ions within a superfluid ⁴He film adhering to the substrate via van der Waals forces. The ions are held within the film by a combination of image forces and an externally applied electric field. Turning off the electric field causes the ions to fall toward the substrate and bond to the substrate surface. If the applied electric field comes from a scanned probe above the film, individual atoms can be deposited with atomic precision. A uniform applied electric field can be used to deposit a crystal of ions onto the substrate.