| AVS 65th International Symposium & Exhibition | |
| Thin Films Division | Wednesday Sessions |
| Session TF+EM+MI-WeA |
| Session: | Thin Film Processes for Electronics and Optics II |
| Presenter: | Hilal Cansizoglu, University of California, Davis |
| Authors: | H. Cansizoglu, University of California, Davis C. Bartolo Perez, University of California, Davis Y. Gao, University of California, Davis E. Ponizovskaya Devine, University of California, Davis S. Ghandiparsi, University of California, Davis K.G. Polat, University of California, Davis H.H. Mamtaz, University of California, Davis M.F. Cansizoglu, University of California, Davis T. Yamada, University of California, Santa Cruz A.F. ElRefaie, W&WSens Devices, Inc. S.Y. Wang, W&WSens Devices, Inc. M.S. Islam, University of California, Davis |
| Correspondent: | Click to Email |
High speed, surface illuminated Ge-on-Si pin photodiodes with improved efficiency are fabricated and characterized. External quantum efficiency (EQE) of the Ge-on-Si pin diode is enhanced to >80% at 1300 nm and 73% at 1550 nm with only 2 µm thick intrinsic Ge layer, which is required to maintain high speed operation. Improved EQE is achieved by guiding incident light into the device structure with the help of microholes arranged in a lattice with a periodicity at the scale of wavelength. Vertically propagating light is coupled to the lateral modes in the material with periodic holes and absorbed efficiently despite a thin layer. More than 350% of EQE is enhanced by hole arrays compared to the case without holes up to 1700 nm wavelength. Such promising results enable Ge-on-Si photodiodes potentially cover both existing C band (1530 nm-1560 nm) and L band (1560 nm-1620 nm) and a new data transmission window (1620 nm-1700 nm), which can be a solution to capacity crunch of conventional standard single mode fiber (SSMF) cables. CMOS/BiCMOS compatible fabrication of photon-trapping Ge-on-Si photodiodes can lead to integrated transceiver circuits with electronics for cost-effective solutions in various near-infrared sensing applications such as metro and long haul dense wavelength division multiplexing (DWDM) systems, laser radar (LIDAR) systems, quantum communications and near-infrared imaging.