Single Carrier Initiated Low Excess Noise Mid-Wavelength Infrared Avalanche Photodiode using InAs-GaSb Strained Layer Superlattice

ABSTRACTMid-wavelength infrared (MWIR) avalanche photodiodes (APDs) were fabricated using Indium Arsenide- Gallium Antimonide (InAs-GaSb) based strain layer superlattice (SLS) structures. They were engineered specifically to have either electron or hole dominated ionization. The gain characteristics and the excess noise factors were measured for both devices. The electron dominated p+-n−-n APD with a cut-off wavelength of 4.13 μm at 77 K had a maximum multiplication gain of 1800 measured at -20 V while that of the hole dominated n+-p--p structure with a cut-off wavelength of 4.98 μm at 77 K was 21.1 at -5 V at 77 K. Excess noise factors were measured between 1-1.2 up to a gain of 800 and between 1-1.18 up to a gain of 7 for electron and hole dominated APDs respectively.