Improvement of surface leakage current of 2.6 µm InGaAs photodetectors by using inductive coupled plasma chemical vapor deposition technology

Abstract

Low surface leakage current is one of the prerequistites to reach the low leakage and high efficiencies of mesa type photodiodes. In this paper, we have studied the surface leakage of 2.6 µm mesa InGaAs p-i-n photodetectors by using two different passivation technologies: inductive coupled plasma chemical vapor deposition (ICPCVD) and plasma enhanced chemical vapor deposition (PECVD). It is found that the total leakage current of the detector with ICPCVD technology is significantly reduced compared to that with PECVD technology due to the decrease of the device's surface leakage current. A TCAD-based dark current model further reveals that the reduction of the surface leakage current at the low reverse voltage is about two orders of magnitude. As a result, ICPCVD is the promising deposition technology for SiN x passivation layer on mesa InGaAs photodetectors.

Impact of residual doping on surface current of InGaAs/InP photodiode passivated with regrown InP

“…The best-performing InGaAs photodiodes have been fabricated in a planar geometry, however, mesa-defined devices are interesting and enable more complex structures such as multiwavelength stacked photodetectors. Nonetheless, while many techniques have been tried for passivating lateral mesas of lattice-matched InGaAs photodiodes, to date, none have succeeded in making the surface leakage negligible when a very low bulk leakage is achieved [10][11][12]. These attempts include sulphur and dielectric passivation.…”

Improved performance of high indium InGaAs photodetectors with InAlAs barrier

“…Many efforts have been devoted to improving the material quality and fabrication processing, such as using different buffer schemes and growth conditions, [2][3][4][5] and adopting superior passivation technologies. 6,7) Another pathway is to utilize energy band engineering to tailor the carrier transport, such as using the so-called nBn or XBn device architecture, where the flow of electrons is blocked by the barrier, but not that of holes. 8,9) For the In 0.83 Ga 0.17 As PD with a cut-off wavelength of around 2.6 µm, taking the lattice match and band offset into consideration, a strain-compensated In 0.66 Ga 0.34 As=InAs superlattice (SL), AlAs 0.28 Sb 0.72 , and In 0.83 Al 0.17 As (hereafter InAlAs) could be potential barrier material candidates.…”