Abstracts Physics

Silicon microlithography using metastable argon((3)phosphorus(0,2)) atoms

by Shannon B. Hill

The design and characterization of an intense source of metastable Ar(3P0,2) atoms is described together with its application in the patterning of Si surfaces. Two different approaches to patterning were investigated. In the first, a hydrogen-passivated Si(100) surface was exposed to the Ar(3P0,2) metastable atom beam, in the presence of a small partial pressure of O2, using a 2000 line/inch grid as a mask. The hydrogen-passivation layer is removed in those areas exposed to the beam, allowing formation of an oxide resist. Subsequent immersion in a KOH solution results in selective etching of the hydrogen-passivated regions, producing an image of the grid on the Si surface with ∼20 nm feature depths. In the second approach, an octadecylsiloxane self-assembled monolayer (SAM) grown on the native oxide of a Si(100) surface was exposed to the metastable atom beam through the grid. Ar(3P 0,2) impact damages the SAM permitting pattern transfer through subsequent plasma and chemical etching. Because metastable atom beams can be manipulated and focused using optical fields, these methods could provide the basis for a new maskless, massively-parallel approach to nanoscale fabrication on Si that is not limited in resolution by space charge or diffraction effects as in conventional charged-beam and optical techniques.