Performance of InGaAs/InP planar infrared detector with different passivation films

摘要

In order to study the effect of different passivation films on the detector performance, the front-illuminated planar-type 256×1 element InGaAs/InP detectors were fabricated with SiN_x film and SiO_2 film. The SiN_x film was deposited by plasma enhanced chemical vapor deposition (PECVD) and SiO_2 film was deposited by magnetron sputtering technology. The electrical properties and photoresponse characteristics were investigated after the detector mounted on dewar. The photoresponse maps from laser beam induced current (LBIC) method show that the isolation of adjacent elements of the detector with SiN_x film is better than the detector with SiO_2 film. Furthermore, at room temperature the average density of dark current and the average peak detectivity of the two kinds of detector is 26.8 nA/cm2 and 41.2 nA/cm~2 at 100 mV reverse bias, 1.21×10~(12) cm·Hz~(1/2)/W and 1.08×10~(12) cm·Hz~(1/2)/W respectively. Therefore, the detector with SiN_x film deposited by PECVD could availably passivate the surface in comparison with the detector with SiO_2 film by magnetron sputtering technology.