The defect density of a SiNx/In0.53Ga0.47As interface passivated using (NH4)2Sx.

Passivation of the electronic defect states at a SiNx/InGaAs interface has been achieved using (NH4)2Sx treatments of the InGaAs surface. The X-ray photoelectron spectroscopy technique was used to investigate the mechanism of sulfur passivation. The results indicate that sulfur treatment can effectively erase the native oxides, and S-In, S-Ga and S-As bondings are formed after sulfidation. The fabrication of Au/SiNx/InGaAs metal–insulator–semiconductor diodes has been achieved by depositing a layer of SiNx on (NH4)2Sx-treated n-InGaAs using the plasma enhanced chemical vapor deposition technique. The effect of passivation on the InGaAs surface before and after annealing was evaluated by current–voltage and capacitance–voltage measurements. The results indicate that the SiNx passivation layer exhibits good insulative properties. The annealing contributes to the decrease of the fixed charge density and the minimum surface state density, which are 4.5×1011 cm-2 and 3.92×1011 cm-2 eV-1, respectively. A 256×1 InP/InGaAs/InP heterojunction short-wavelength infrared detector, fabricated with the sulfidation plus a SiNx passivation layer, has shown a good response uniformity of 4.81%. [ABSTRACT FROM AUTHOR]