CONSTRUCTIVE 3-DIMENSIONAL LITHOGRAPHY WITH ELECTRON-BEAM-INDUCED DEPOSITION FOR QUANTUM EFFECT DEVICES

Two- and three-dimensional patterns and structures can be grown by electron-beam induced deposition from organic and metalorganic precursors. Using a very fine electron beam in a dedicated field emission scanning electron microscope produces nanometer size deposits which extend from surfaces to heights in the micrometer range. The material is fed to the sample through a nozzle which presents a small leakage flux to the specimen chamber. Having an image processor attached to the microscope allows two- and three-dimensional deposition of material to be controlled. Selecting special speed rates for the motion of the beam generates inclined deposits even at a 90-degrees beam landing angle. Combining a tilted sample and the two-dimensional way of structuring yield three-dimensional structures. These nanostructures have very special characteristics with respect to resistivity and shape. Selecting dimethyl-gold-trifluoro-acetylacetonate as precursor, a current of 1 nA, and a low electron energy of 10 keV for the deposition process, resistors of 700 OMEGA are obtained with a specific resistivity of 10(-2) OMEGA cm.