Inorganic Self-Assembly Routes to Three-Dimensional Memories and Logical Mesostructures.

摘要

This work sought to develop chemical components and self-assembly techniques for molecular electronic circuits. Specific objectives were to use membrane replication methods to make segmented metal and semiconductor rod colloids, and to develop techniques for assembling them into cross-point arrays for functional circuits. The major accomplishments were demonstration of nanowire synthesis down to diameters of 12 nm with aspect ratios exceeding 100, development of an electrofluidic technique for aligning and measuring the electronic conductivity of individual wires, and development of chemical control over the assembly of nanowires. The latter involved orthogonal self- assembly of molecules onto electrochemically defined V stripes' along the wire length. Using DNA base pairing, suitably striped wires could be assembled into cross- and T- junctions, and onto lithographically defined patterns on surfaces. Methods were developed for layer-by-layer growth of concentric shells of insulators and conducting polymers on the nanowire walls. This allows the crossing of insulated wires without shorts and crossing of functionalized wires for memory or logic function. Fluidic techniques were developed for making 2-D arrays of nanowires assemble into ordered rafts in microwells. Together these advances provide potentially useful materials and techniques for the realization of very dense (more than 10 billion devices per square centimeter) self-assembled electronic circuits.