Low Dark Current InGaAs(P)/InP p–i–n Photodiodes

Abstract

Planar InGaAs(P)/InP p-in photodiodes have been successfully fabricated by low-pressure metalorganic chemical vapor deposition (LP-MOCVD). High-quality and uniform epitaxial layers are obtained. It is noted that the InGaAs layer background concentration is as low as 4:5 Â 10 13 cm À3. The dark current is significantly reduced by using a wider-band-gap material of quaternary In x Ga 1Àx As y P 1Ày as a cap layer to reduce the device surface leakage current. In addition, the device becomes highly photosensitive due to the reduction of the absorption of the radiation in the narrow-band-gap In x Ga 1Àx As y P 1Ày cap layer. The p-in photodiode with a wide-band-gap InP cap layer exhibits a dark current as low as 60 pA at À10 V bias, corresponding to a dark current density of 4:2 Â 10 À7 A/cm 2 .

Effect of AlGaAs cladding layer on GaInNAs/GaAs MQW p‐i‐n photodetector

“…There have been a few results reported showing the contribution of the cladding layer to the photodetectors [5,6]. From these results, one can surmise that the cladding layer with a higher band discontinuity provides a barrier height to hinder the carriers surmounting it and reduces the leakage current.…”

“…To reduce the dark current of the p-i-n photodetectors, usually not only the crystal quality of the epitaxial layers improvement but also the surface passivation process is fabricated. For band structure design, either one or both of the p-and/or n-regions are applied with materials having an energy band gap higher than that of the absorption layer, thus forming single or double heterojunctions to depress the tunneling current [5,6]. This design of a cladding layer has been employed on laser diodes to improve device performance.…”

Optical and Structural Properties of MOCVD Grown InxGa1-xAs Epilayers

“…For instance, it is commonly used in tandem solar cell structures [3], laser diodes [4], and p-i-n photodiodes [5]. In x Ga 1-x As is mostly grown with MOCVD and MBE (Molecular Beam Epitaxy) on single crystal substrates [3][4][5]. MOCVD has advantageous for example, it is possible to obtain high crystal quality layer at very high growth rate with multiple growths at once.…”

Novel 3D modeling of In 0.53 Ga 0.47 As lateral PIN photodiode

“…On the other hand LPPs have low dark currents, permits a large detection area along with a low device capacitance, and can be monolithically integrated with other devices. LPPs can also be easily fabricated using standard CMOS technology such as diffusion or ion implantation 4-5 . In optical transmission systems operating at wavelengths of 1.0 to 1.65 µm, PDs are usually made of In 0.53 Ga 0.47 As (subsequently InGaAs), which has a bandgap of 0.75 eV and is lattice matched to InP (Eg = 1.35 eV) [6][7] . InGaAs is chosen as the absorption material since there is substantial technology developed for the fabrication of lasers, LEDs and diodes [8][9] .…”