Fall 2012 IAB & Research Review
September 19 to 21
Chemical Sensor using Optical Antenna
Optical antennas are widely used for chemical sensing such as surface-enhanced Raman scattering (SERS) because of their ability to focus light in sub-diffraction-limited area, resulting in strong field enhancement. The field enhancement depends critically on the gap spacing of optical antennas, however, current nanofabrication techniques are limited by poor uniformity and reproducibility as the dimension decreases below 10 nm.
In this talk, we report on the design and demonstration of new optical antennas with reproducible uniform sub-5nm gap spacing using deep-UV spacer lithography. Strong surface-enhanced Raman scattering (SERS) signals with an enhancement factor of 10^8 have been measured, which is two orders of magnitude improved than standard dipole antennas fabricated by typical e-beam lithography. Since the proposed new antennas can be made by deep-UV lithography, uniform SERS substrates with sub-5nm gap optical antennas can be mass produced in existing Si CMOS foundries.