In this work, we design and produce 1280x1024 format InGaAs based planar type detectors with 15μm pixel pitch. We have obtained diffusion current limited low dark current (~10fA) and high responsivity (1.08A/W at 1.55μm) values at room temperature conditions. Moreover, dark current modeling is performed using diffusion, generation and recombination (GR) and trap assisted tunneling (TAT) current mechanisms. Ideality factor is extracted from forward bias characteristics. Excellent match between modeling and experimental data is reached. Also, temperature dependency of dark current is studied in 10°C – 60°C ranges. The area and perimeter related dark current components are differentiated using test detectors with changing diameters that are placed next to the detector array structure. Experimental data shows good agreement with theoretical expectations.
We design lattice matched InP/In0.53Ga0.47As mesa structured heterojunction p-n photodiodes with a novel passivation methodology based on a fully depleted thin p-InP layer. Mesa-structured detectors are targeted due to their competitive advantages for applications such as multicolor/hyperspectral imaging. Test detector pixels with different perimeter/area ratios are fabricated with and without etching thin InP passivation layer between pixels in order to comparatively examine passivating behavior. I-V characteristics of the test detectors are measured at room temperature. Based on the results from different sized pixel groups, bulk and surface dark current components are separated. Results show that thin InP layer decreases dark current by a factor of 3 while increasing photo current due to a higher carrier collection efficiency.