Back-illuminated separate absorption and multiplication GaN avalanche photodiodes

The performance of back-illuminated avalanche photodiodes with separate absorption and multiplication regions is presented. Devices with an active area of 225μm2 show a maximum multiplication gain of 41 200. The calculation of the noise equivalent power yields a minimum value of 3.3×10−14WHz−1∕2 at a gain of 3000, increasing to 2.0×10−13WHz−1∕2 at a gain of 41 200. The broadening of the response edge has been analyzed as a function of bias.