Microelectronic systems have many highly interconnected components. Future manufacturing methods for nano-devices on the molecular scale will need to deliver at least the same level of interconnection using a compatible process. Ribo-nucleic acid (RNA) folds to form simple tertiary structures. Since the folded structure of a given sequence of RNA can be predicted, sequences that fold into desirable branched nanoelectronic structures will be made. Families of structures that can link up to form tessellated ensembles and multiply connected structures will be investigated. These structures will be used to position electronic materials for devices, and electrical characterisation will be done. We will study pattern transfer to conventional electronic substrate to demonstrate arbitrary sub-10nm lithography via direct metalisation of the RNA, or by indirect pattern transfer.
Novel oligo-RNA designs to form tecto-RNA (tesselated) multimers to define structured nano-scale features. Methods of immobilising large tecto-RNA structures to substrates (as opposed to single oligomers). Methods of transferring the aforementioned nano-scale RNA templates to pattern and interconnect electronic materials and/or metals. Functionally activate RNA multimers using the intercalation or chelating of nano-particles. A self assembled route to spatially programmed surface modification. Multi-probe measurements on molecular nano-devices and transport data on these new structures and devices.
DESCRIPTION OF WORK
We will further the science and technology of fabricating novel nano-devices and interconnection between nano-devices. A self-assembly technique based on the secondary Watson-Crick base-pairing and folded tertiary structure of natural and synthetic RNA will be used to build templates. The templates will be built hierarchically, using the behaviour of RNA, to mimic the structured approach to design that is used in VLSI. The nature of RNA folding will enable us to deposit large 2D structures on to planar electronic, substrates. The templates will be used to provide lithographic masks for the fabrication of electronic interconnection by one of two metalisation processes: direct metalisation of the RNA using oligo-functionalisation and electrochemical means, and deposition of the RNA on to a substrate for use as a masking material for electro-forming. These technological developments will rely upon the creation of new methodologies for immobilising raft-like RNA multimers on to Si/SiO2 or Au treated substrates. The second purpose of the RNA technology is to act as a host to nano-particles that will be functionalised to bond to key positions on the RNA. This creates the possibility for having spatially programmable attachment of materials to surfaces, hence a means of assembling circuit elements on a connected grid, or a means of building memory that can be accessed by a scanned read head. These structures will contain sub-10 nm features over a large area (> 100 nm), and two methods of electrical characterisation will be employed: scanned probe microscopy (Scanning tunnelling spectroscopy (STS) and scanning tunneling microscopy (STM)) to access individual nano-particles, and direct electrical measurement of ensemble transport properties using prepatterned electrodes on test substrates. In either case, the large overall dimension of the nano-structure will enable a diversity of electrodes to be placed in close proximity to the RNA using electron beam lithography.
Funding SchemeCSC - Cost-sharing contracts
L69 3BX Liverpool