Ryan Going graduated from North Carolina State University in 2009 with BS degrees in Electrical Engineering and Applied Mathematics. In 2010 he completed his MPhil in Micro- and Nanotechnology Enterprise at the University of Cambridge as a Gates Cambridge scholar. He is currently working on his PhD under Prof. Ming Wu, focusing on silicon photonics and photodetectors.
Ultra-Sensitive Photodetectors on Silicon Photonics [BPN609]
As CMOS devices shrink in physical size, electrical interconnects between the devices will consume an ever-greater proportion of total chip power. A promising solution is to use silicon photonics for intra- and inter-chip communications. To be cost effective, both the optical transmitter and receiver should be made small, highly efficient, and CMOS compatible. Shrinking the photodiode will increase sensitivity and energy efficiency, but as it gets very small, the capacitance of the wire to the first amplifying stage in the receiver becomes significant. We present a solution which integrates the photodiode and first stage transistor in the form of an integrated germanium phototransistor. The rapid melt growth technique is used to integrate high quality single crystal germanium onto a silicon waveguide integrated device in a CMOS process. Bipolar gain combined with extremely compact device dimensions produces high-speeed, high-sensitivity receivers which operate at 1550 nm on a silicon photonics platform.