Revolutionary Photoreceivers Based on Combining Si-MOS Process with Ge Technology

We propose to design and to fabricate high-speed infrared receivers using germanium-based detectors integrated monolithically with silicon circuits. Earlier work by us has demonstrated germanium photodiodes integrated on silicon substrates with low dark current and high speed, suitable for 10Gb/s operation. We propose to further optimize the photodiode design for 40Gb/s applications, and to monolithically integrate a high speed, low-noise transimpedance amplifier to form an infrared receiver fabricated on top of a standard silicon foundry process. During phase I, we will measure the speed and sensitivity of a variety of photodiode geometries to determine the effect of device geometry and contact layout. Using this information, coupled with simulations and calculations, we will determine the device design changes necessary for higher speed operation. During Phase II, we will design the receiver circuit and fabricate prototypes in partnership with our silicon foundry producer. Extensive characterization and performance measurements will be made and prototypes delivered to the Air Force.