Nanostructure patterning

Research at the US Naval Research Laboratory (NRL) in the lithography, patterning, and fabrication of structures of nanometer scale dimensions is reviewed. Electron-beam (e-beam) lithography at high (50 keV) and low (5 eV) energies on resist systems developed at NRL is described. The low energy lithography takes advantage of the spatially confined e-beam available in a scanning tunneling microscope type probe. This instrument allows an in situ exposure and characterization of an e-beam sensitive material. A novel approach for implementing dose correction for proximity effects in e-beam lithography is presented using an error measure based on the physical realities of lithography. The compositional disordering of GaAs-Ga_xAl_1-xAs heterostructures as a technique for pattern replication is described. Introducing silicon into the heterostructure (by implantation or diffusion) enhances the aluminum and gallium interdiffusion which can be used for patterning. A complete bibliography of recently published results is included