Nanotechnology and Nanoelectronics

Anti-reflective biomimetic "moth-eye" structure can enhance the output power of a solar cell by up to 10%

As silicon technology enters the nanoelectronics era, remarkable opportunities exist to combine nanomaterials, quantum phenomena and microelectronics technology in creative ways to produce new types of silicon-compatible device for a wide range of applications. The world-class electron beam lithography capability in the NSI Group allows us to research new nanomaterials that have interesting electrical, optical and magnetic properties, and also to apply these nanomaterials to improve the performance of silicon devices. One example of our research is the use biomimetic and plasmonic nanostructures on the surface of a silicon solar cell to improve its efficiency.

Bundle of four single-wall carbon nanotubes grown from germanium nanoparticles

Bottom-up, self-assembly techniques are also important for the fabrication of nanomaterials, particularly when the critical dimension is below 5nm. Here the key research issues are silicon compatibility and the guiding of the self-assembly to allow nanomaterials to be accurately and reproducibly placed in precise locations on a silicon wafer (directed self-assembly). The NSI Group has state-of-the-art PECVD and LPCVD deposition systems for the growth of silicon, germanium and oxide nanowires, carbon nanotubes and germanium quantum dots. These materials have interesting electrical, optical and mechanical properties that make them very attractive for new types of device. One example of our research is the development of a new carbon nanotube growth method that uses germanium nanoparticles as seeds for nanotube growth. This metal-free growth method is attractive for silicon technology, as it eliminates the metal contaminants that are present in the standard carbon nanotube growth method.

Approaches are being researched for the directed self-assembly of magnetic nanodots using self-assembled latex spheres and colloidal solutions. Lithographic patterning of the silicon wafer forces the self-assembly of spheres into a regular structure, which would allow magnetic storage to reach much higher density. For example, a self-assembled array of 20x20 10nm dots with 10nm spacing would provide Tbit/inch2 storage at a lithographical resolution of only 0.4um instead of 10nm. Main issues are the ordering of the self-assembled spheres, the adhesion of the magnetic material to silicon and the shape and anisotropy of the magnetic dots.

SEM cross-section through a vertical MOSFET incorporating a technology (FILOX) for reducing overlap capacitance

Approaches are being researched for the directed self-assembly of magnetic nanodots using self-assembled latex spheres and colloidal solutions. Lithographic patterning of the silicon wafer forces the self-assembly of spheres into a regular structure, which would allow magnetic storage to reach much higher density. For example, a self-assembled array of 20x20 10nm dots with 10nm spacing would provide Tbit/inch2 storage at a lithographical resolution of only 0.4um instead of 10nm. Main issues are the ordering of the self-assembled spheres, the adhesion of the magnetic material to silicon and the shape and anisotropy of the magnetic dots.

Current Research Activities

Current research activities include:

People in Nanotechnology