Nanoscale Foundries: Electronics, Photonics, Ionics, Fluidics
Friday 04/05/2019, 4:00pm, room 3-270
Modern silicon fabs routinely produce functional electrical components for a few dollars at part counts exceeding billions per year and a complexity rivaling the human genome. The productivity of these fabs is ensured by design rules that govern the structures that constitute these systems. These design rules govern the range of sizes and separations between various materials - from silicon to metals and dielectrics. However, the essential design rules do not dictate function. For example, MEMs structures have been realized in silicon without modification of the design rules (so called zero-change). Here, we show that the manufacturing infrastructure and design rules support a host of functions and applications beyond electronics - to include nanoscale photonics, ionics, and fluidics.
For example, the thin silicon layers that comprise the body of a silicon transistor can be repurposed to realize a full suite of infrared waveguides, optical resonators, high-speed optical modulators and detectors. By adhering to the structural design rules dictated by the silicon fab, these nanophotonic elements can be embedded with intelligence and scaled to VLSI complexity for consumer applications and cost. These photonic components enable 'native' optical I/O with bandwidth densities and powers unrealized with electrical interconnection. The complexity of CMOS lies both within the silicon layer and within the metal wiring that interconnects the billions of transistors together. A modern fab produces a dozen or so layers of intricately routed copper interconnects - the finest of which is fabricated on the sub-100nm scale. We have recently demonstrated that these metal layers and the high-quality dielectrics between them can support electric fields that trap and manipulate single charged atoms (ions). We have demonstrated long-term trapping of single ions as well as arrays of ions in a vacuum above the chip surface. The isolation of the ions from solid surfaces preserves their quantum coherence. Further integration of these ionic devices with photonics enables a class of high-fidelity quantum logic and precise atomic clocks that can be integrated at the chip scale. Finally, the dielectric structures that surround and isolate individual transistors can be utilized to realize nanometer size templates for self-assembly at gigascales. We have recently demonstrated nanofluidic components that utilize the transistor dielectrics as fluid channels with femtoliter volumes fabricated alongside sensitive electronics and photonics. Such a platform may one day enable manipulation and measurement at the scale of single molecules with parallelism reaching billions of simultaneous measurements.
The most important aspect of the technology and examples above is that these nanoscale structures in silicon, copper, and glass are available to the public. We utilize open foundries (such as MOSIS) that support many users sharing the cost of fabrication. Our nanoscale photonics, ionics, and fluidics are realized next to the electronic circuits designed by small and large companies, students from around the world, and people who just like to tinker. They are the machine shops of the nano-era.
Refreshments will be served before the Seminar.
Host: Mathias Kolle (mkolle@mit.edu)
Co-organizers: Mathias Kolle (mkolle@mit.edu) and Cullen Buie(crb@mit.edu)
Coordinator: Tony Pulsone (x3-2294, pulsone@mit.edu)