Investigating the effect of number of metal electrodes on performance parameters of AlGaN MSM photodetectors

In most past studies, MSM (Metal-Semiconductor-Metal) detectors with the varying area have been investigated for varying number of fingers (metal electrodes) of equal width (W) and spacing (S). Therefore, there is a need to investigate fixed area MSM detectors with varying number of fingers as there are few reports on electrical analysis of larger electrode spacing dimensions. In the current work effect of variation in the number of fingers is studied for two types of Al0.5Ga0.5N/AlN/Sapphire based fixed area MSM detectors. Comparative performance analysis between (S = W) and (S = 2W) based detectors is carried out for photocurrent, dark current density and transient response. I-V characteristics, structure diagram plots are generated using the TOAD Silvaco simulator. It has been observed that S = W detectors exhibit higher photocurrent and lower dark current density is shown by S = 2W designs. Therefore, simulation outcomes can be beneficial for selecting suitable MSM detector for reliable, high-speed optical communication and switching applications.