Improvement of RTS Noise in HgCdTe MWIR Detectors

Random telegraph signal (RTS) noise is present in all bands of the infrared spectrum from λ c = 2.5 μm (short-wavelength infrared) to λ c = 15.75 μm (very long-wavelength infrared) and decreases the performance of infrared photodetectors. The main features of RTS noise such as the jump amplitude and RTS frequency are defined, and their dependence as a function of focal-plane array (FPA) temperature was measured for all bands of the infrared spectrum. Both of these features comply with a Boltzmann activation law \( \left( { \propto {\hbox{e}}^{{\frac{{ - E_{\rm{a}} }}{k_{\rm B} T}}} } \right) \), and their activation energies scale with the bandgap. Comparison of three different HgCdTe mid-wavelength infrared photodetector technologies was also performed, showing that the optimized n-on-p improvement of operability (AOP) and p-on-n high-operating-temperature technologies show a reduced number of pixels exhibiting RTS noise (by about two decades) in comparison with standard n-on-p technology.