Resonant cavity photodetectors in silicon-on-insulator

Silicon-on-insulator (SOI) substrates are becoming commercially available for high-performance ICs. These substrates have a buried layer of SiO2 that prevents carriers that are generated deep in the crystal from being collected at long time delays and thus improves the speed. Previous work with e-beam written finger-spacings has indeed shown that the slow tail in the pulse response is eliminated by using SOI substrates. However, the devices were optimized for very high speeds and necessarily had low efficiencies. This work examine the trade-off between speed and efficiency and present devices that are suitable for optical data link applications.