A SILICON-BASED INTEGRATED NMOS-P-I-N PHOTORECEIVER

For large-volume optoelectronics applications, the low cost, manufactu rability and reliability of silicon MOSFET technology are advantageous , In addition, silicon photodetectors operate quite efficiently at the 850 nm wavelength of economical AlGaAs light sources, In this paper, we report on a silicon-based monolithic optical receiver, The fabricat ion of the integrated lightwave receiver was carried out on a nominall y undoped p-type Si substrate, The p-i-n photodetector was fabricated directly on the high-resistivity substrate so that the thickness of th e detector depletion layer was approximately equal to the optical abso rption length of 850 mm light in silicon. A more heavily-doped p-well was formed for the NMOSFET fabrication, The silicon photodiodes had a dark current of 20 nA at 5 V, a breakdown voltage greater than 60 V, a nd a zero-bias capacitance of 40 fF, The external quantum efficiency o f the photodiode at 870 mn was approximately 67% at 5 V without an AR coating, and the bandwidth of the device was approximately 1.3 GHz, Fr equency response evaluation of the receiver indicated a circuit-design -limited bandwidth of 30 MHz with open eye diagrams demonstrated at 40 MB/s.