Effects of the passivation process on the electrical characteristics of GaInAs planar photodiodes

The electrical properties of GaInAs PIN photodiodes passivated by a silicon nitride film have been compared for different deposition techniques: CVD, PECVD, UVCVD. Passivation induced defects have been observed by admittance spectroscopy and DLTS measurements. The nature, density and profile of these defects are found to be strongly dependent on the deposition process. The latter also largely influences the dark current and its temporal stability.