PLANAR INP/INGAAS AVALANCHE PHOTODETECTORS WITH PARTIAL CHARGE SHEET IN DEVICE PERIPHERY

A novel planar separate absorption, charge sheet, grading and multiplication avalanche photodiode (APD) structure incorporating a partial charge sheet in the device periphery is described, which allows for straightforward fabrication of APD devices without the use of guard rings. Metalorganic chemical vapor deposition grown, Zn-diffused InP/InGaAs APD devices have been fabricated. High dc gains well in excess of 100 and a low primary dark current of 0.1 nA at 0.99 of the breakdown voltage VB have been measured for a 40-μm-diam device. The receiver sensitivity for a bit error rate of 10-9 at a bit rate of 400 Mbit/s was -41 dBm. The -3 dB electrical bandwidth was 2.5 GHz, and the gain-bandwidth product was 30 GHz.