Sub-wavelength patterning with interference lithography (Blaikie, Alkaisi)

Sub-wavelength patterning will be achieved using optical interference lithography (IL), to complement existing electron-beam, nano-imprint and near-field optical nanolithography techniques.  This will bring advantages of simplicity and the ability to pattern over large areas (~cm2), and we will use this technique to provide patterned substrates for other Institute research. Objective 1.  Sub-wavelength patterning with interference lithography (Blaikie, Alkaisi). A new 325nm HeCd laser system has now been established, and conventional Lloyd’s mirror interference has been demonstrated with resolution down to below 200 nm. Patterns at this scale are already being used for surface texturing solar cells in a FRST-funded program, and we will now look to refine the process and improve the resolution for other applications. This will be achieved by implementing a novel solid-immersion version of the Lloyd’s mirror that will offer resolution below 50 nm (using a special Yttrium Aluminium Garnet solid-immersion prism currently on order); the capabilities of this system for reliably patterning nanostructure arrays at this resolution will be tested in the coming year. Such nanostructure arrays will then be offered as test samples for other Institute programmes investigating: silicon nanowhisker growth (Theme 1) carbon nanotube growth (Theme 3) and hybrid substrates for catalysis (Theme 5).