InGaN-Based MSM Visible Light Photodiodes With Recessed Anode

In
_0.17
Ga
_0.83
N-based metal-semiconductor-metal photo-diodes (MSM-PDs) with recessed anode electrodes were fabricated and characterized. The photodiodes exhibited low dark current of 8 × 10
^-12
A at 5 V, which was one order lower than that of the conventional planar MSM-PDs. Peak responsivity up to 0.22 A/W was obtained at 430 nm and 1.5 V, corresponding to an external quantum efficiency of 63%. The 440 nm/490 nm rejection ratios of the recessed and planar MSM-PDs were ~10
³
and 10
²
, respectively. The improvements were attributed to the suppression of lateral surface leakage current and the enhancement of the internal electric field by the recessed anode electrodes.