Research & Prototype Foundry and cleanroom
A key activity in the field of nanoscience is the fabrication of new electronic, photonic, and mechanical devices small enough to access the exotic phenomena that arise on the nanoscale, so the Sydney Nanoscience Hub contains the high-precision Research and Prototype Foundry and cleanroom.
What is a cleanroom?
Building nanodevices requires special tools for patterning materials and ‘writing’ new elements – such as tiny wires – onto substrates. Because the size scales are so small, tiny bits of airborne dust can completely destroy a device – the dust can be many thousands of times larger than the wires. As a result we undertake nanofabrication in special cleanrooms where the air is filtered to remove the dust.
Cleanrooms are controlled environments with tightly regulated temperature and humidity, and very low levels of particulates. Cleanrooms are classified by the maximum level and sizes of particulates per unit volume present in the air. The Sydney Nanoscience Hub contains two levels of cleanroom, ISO Class 5 and ISO Class 7, comparable to production-level facilities found in major semiconductor foundries. The cleanrooms are the flagship facility of our core research facility: the Research and Prototype Foundry.
Inside a cleanroom
Working inside a cleanroom requires special protocols to limit contamination. These include full cleanroom suits, including masks and boots, ‘air showers’ and ‘sticky’ doormats which remove dirt from the soles of your shoes, as well as air filtration.
Lighting in cleanrooms is yellow, to prevent incidental exposure of the photoresists that are used in nanofabrication. Nanofabrication often involves building devices by shining light through special ‘masks’ that cast a shadow on the substrate. A light-sensitive chemical placed on the substrate changes in the areas where the light passes through the mask and can then be washed away leaving the desired pattern transferred to the substrate. The chemicals are typically sensitive in ultraviolet light, so we have to prevent background light from changing the chemical before patterning, so yellow lighting is used in the cleanrooms.
Precision air conditioning in the cleanroom continuously supplies 25,000 cubic metres per hour of highly filtered and conditioned air that maintains the particulate level to less than 100 particles (at a size no greater than 0.5 micron) per cubic foot of air. This is 100 times cleaner than air in a medical operating theatre!
The water in the cleanroom is also extremely clean, with a deionised water plant that supplies 5000 litres of 18.2 MegOhm ultrapure water to the cleanroom.
The Research and Prototype Foundry’s cleanroom in the Sydney Nanoscience Hub will contain a wide range of equipment for making nano and microstructures in a variety of materials. These will include deposition methods for photoresists, metals, insulators and other materials; equipment to expose or write nanostructures; highly controlled methods of etching and removing material; and characterisation tools. Some of the first equipment to be installed includes: electron beam and photolithography tools, spin-coating and sputtering systems, etching systems, and electron and optical microscopes.
Who will use the cleanrooms?
The Sydney Nanoscience Hub cleanrooms will provide subsidised access to leading edge facilities, not just to the University of Sydney, but also the wider Australian community. We are partners with the Australian National Fabrication Facility (ANFF), which is a federally funded national organisation. The cleanroom facilities will allow researchers and industry across the country to make nanodevices and prototype new ideas. The nanofabrication we expect to do includes nano-electronics, optical chips, microfluidic devices and micro and nano-electronic mechanical devices (MEMs and NEMS).