Fabrication of Metallic Structures in the 10 nm Region Using an Inorganic Electron Beam Resist

Abstract
In order to make the sub-10 nm region accessible to lithography, an ultrahigh-resolution electron beam resist has been developed. This inorganic and self-developing resist is based on AlF3-doped LiF films. The resolution limit is ≈3 nm lines & spaces. This result is in excellent agreement with a rule which gives a correlation between resolution and threshold energy of a resist. The sensitivity is sufficient for the fabrication of complex mesoscopic devices. The problems concerning pattern transfer are discussed. As a first result, metallic structures with lateral dimensions down to 10 nm have been obtained using a lift-off technique.