Home – Home – Jornals – Avtometriya 2024 number 2

The methods of passivation of photodetector mesastructures based on InSb/In_1-xAl_xSb nBn heterostructures grown by molecular beam epitaxy have been investigated. The mesastructures are formed by photolithography and liquid etching methods. For passivation of the mesastructure surface, two different dielectrics Al₂O₃ and Si₃N₄ are used. It is shown that the Si₃N₄ dielectric completely passivates the surface of mesastructures and the bulk current is prevailing, while the surface leakage current dominates in mesastructures passivated by Al₂O₃. At small reverse biases, the correlation between the current value and the contact area is violated due to the influence of defects. Modelling of the mesastructure current-voltage characteristics at 77 K shows that the main contribution to the dark current is made by the tunneling current of electrons through the In_1-xAl_xSb barrier.