Physics (Internal)
Quench Condensed Atomic Calligraphy
This event is part of the Biophysics/Condensed Matter Seminar Series.
Abstract: The Fab on a Chip approach is a novel fabrication technique that leverages the control and stability of MEMS machines to fabricate structures on the nano-scale. This contrasts to standard deep-UV and e-beam lithography methods typically used today. We are developing a method of nano-fabrication that can be operated in a cryostat to enable novel physics experiments. To this end, we built MEMS-based machines that mimic typical macroscopic tools found in a modern nano-fabrication facility. The central component of the micro-fab is the writer. This dynamic stencil is controlled by orthogonal electrostatic comb drives. A central mask and aperture are positioned with nanometer accuracy, allowing for the precise placement of the desired material (lithographic mask). The intensity of the incoming atom flux is measured with a MEMS-based mass sensor (film thickness monitor). Whereas a large atom flux is achieved through a conventional source, a micro heater can supply a small number of atoms to customize a device (source). Between the aperture and source, a MEMS shutter controls the precise timing of the incoming atoms. Thermal sensors and heaters provide further information of the state of the fab and give critical feedback control. The low power and small footprint enable the setup to function in a cryogenic environment. We demonstrate basic functionality of the elements at liquid-helium temperatures. The advantage of resist-free lithography and of the deposition being the final fabrication step is the ability to pattern materials incompatible with standard techniques. Furthermore, the ultra-clean environment is suited for high-purity fabrication of structures made of exotic materials such as lithium, with the intent to enable novel electron-transport experiments. The current status of this fabrication method will be presented, with focus on the dynamics of the aperture-shutter ensemble and on patterned structures made at cryogenic temperatures.