This Small Business Innovation Phase I Project addresses a novel chemical approach to fabricating copper interconnects for integrated circuits. A silicon/silicon dioxide wafer surface will be patterned by electron beam writing using a charge-writing scanning electron microscope with lines 30 nm in width; these will then be decorated with positively charged l.4 nm gold nanoparticles from solution. These will be the seed layers for autometallographic deposition of metallic copper from a solution containing copper (II) ions in a selectively reducing environment. Before electron beam charge-writing is attempted, the individual steps in the process will be optimized using a modified xerographic or laser printer: instead of charged carbon, the amorphous selenium or cadmium sulfide transfer roller will be used to transfer the charged gold clusters onto membranes, where the patterns will be visualized by copper autometallography. The proposed approach may enable the fabrication of copper interconnects 30 nm (O.03 um) in width, significantly smaller than the 0.18 um which is the smallest current width, resulting in higher chip packing density and further miniaturizing the construction of electronic components. This chemical approach will also simplify IC fabrication by removing the photoresist masking and metal etch steps.
