Solid State Technology and Devices Seminar: Hacking CMOS: Electronics, Photonics, Ionics, Fluidics

Seminar: Solid State Technology and Devices: EE: CS | January 31 | 1-2 p.m. | Cory Hall, The Hogan Room, 521

 Rajeev Ram, Professor, Department of Electrical Engineering & Computer Science, MIT

 Electrical Engineering and Computer Sciences (EECS)

Here, we show that CMOS 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. Our recent work has extended this CMOS photonics platform across wavelengths from UV to IR and applications from quantum computing to molecular sensing. The complexity of CMOS lies both within the silicon layer and within the metal wiring that interconnects the billions of transistors together. 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

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