Miniaturization and Integration of Devices through Lithography
Axel Scherer, Distinguished Visiting Professor, Thayer School of Engineering
Friday, October 14, 2011, 3:30pm
This seminar is part of the Jones Seminars on Science, Technology, and Society series
Over the past decades, lithography and high-resolution pattern transfer have enabled the fabrication of nanostructures with lateral sizes of 10nm and below. These capabilities, together with atomic thickness accuracy offered by modern crystal growth, have resulted in the definition of designed nanostructures. More recently, the challenge has been to integrate such nanostructures into functional devices, and to take advantage of the opportunities of miniaturization. For example, commercially available silicon transistors are now constructed with ~30nm features, lithographically aligned with great precision and integrated in complex chips that are manufactured on 300mm wafers. In this presentation, the possibility of fabricating even smaller transistors with ~3nm lateral dimensions will be described. In such nanostructures, both device and material properties can be controlled through geometry rather than composition.
Another exciting opportunity derived from fabricating devices lithographically arises from the possibility to accurately align devices with different functions to one another. This capability results in integrated systems of nanoscale devices, in which electronics can be combined with optics, fluidics or magnetics on monolithic chips. We will show how integrated microsystems can form the basis of new functionality and reduce the cost or complexity of biomedical, telecommunications and chemical sensing chips. For example, we have developed microfluidic chips in which electronic signals can control picoliter volumes of solutions, and which can be integrated with ion-sensitive transistors, capacitors, inductors, magnets and even fluorescent detectors to measure local chemistry. Such systems can now be made inexpensively with the promise of providing molecular pathology to underserved populations in the world. Another interesting opportunity of miniaturization of system is focused on compact implantable systems, powered and communicating without wires. Wireless probes that measure chemistry changes of voltages may serve as health monitors, identify the onset or progression of diseases, and even hold the promise of understanding complex metabolic functions.
About the Speaker
Dr. Axel Scherer is the Bernard A. Neches Professor of Electrical Engineering, Applied Physics and Physics at Caltech as well as a visiting professor at Dartmouth. He received his PhD in 1985, and after working in the Microstructures Research Group at Bellcore, he joined the Electrical Engineering option at Caltech in 1993. Professor Scherer's group now works on micro- and nanofabrication of optical, magnetic and fluidic devices. He has co-authored over 300 publications and holds over 70 patents in the fields of optoelectronics, microfluidics, and new nanofabrication techniques. Professor Scherer has co-founded three high-technology companies and built a state of the art cleanroom for advanced high-resolution lithography and pattern transfer at Caltech. He has pioneered microcavity lasers such as vertical cavity surface emitting lasers, microdisk lasers and photonic crystal lasers in many materials systems. Presently, his group works on integration of microfluidic chips with electronic, photonic and magnetic sensors. His group has also developed silicon nanophotonics and surface plasmon enhanced light emitting diodes, and has perfected the fabrication and characterization of ultra-small structures with sizes down to 2nm.