ABSTRACT
We report design improvements for evanescently coupled Germanium photodetectors grown at low temperature. The resulting photodetectors with 10 µm Ge length manufactured in a commercial CMOS process achieve >0.8 A/W responsivity over the entire C-band, with a device capacitance of <7 fF based on measured data.
Subject(s)
Amplifiers, Electronic , Germanium/chemistry , Light , Optical Devices , Semiconductors , Surface Plasmon Resonance/instrumentation , Computer-Aided Design , Equipment Design , HumansABSTRACT
We propose and demonstrate a novel Ge photodetector on silicon-on-insulator based on a junction field effect transistor structure, where the field-effect transistor gate is replaced by a Ge island with no contact on it. Light incident on the Ge switches on the device by altering the conductance of the Si channel through secondary photoconductivity. The device's sensitivity is also enhanced by a vast reduction in parasitic capacitance. In cw measurements, proof-of-concept detectors exhibit up to a 33% change in Si channel conductance by absorbing only 200 nW of power at 1.55 microm. In addition, pulsed response tests have shown that rise times as low as 40 ps can be achieved.
ABSTRACT
The continued scaling of integrated circuits will require advances in intra-chip interconnect technology to minimize delay, density of energy dissipation and cross-talk. We present the first quantitative comparison between the performance of metal wire interconnects, operated in the traditional manner by electric charge and discharge, versus the performance of metal wires operated as surface plasmon waveguides. Surface plasmon wire waveguides have the potential to reduce signal delay, but the high confinement required for low cross-talk amongst high density plasmon wire interconnects significantly increases energy dissipation per transmitted bit, above and beyond that required for electric charge/discharge interconnects at the same density.
