Reliability of Silicon Avalanche Photodetector in Geiger Mode

APDs are high-gain semiconductor diodes that produce an avalanche effect at reverse bias voltage, also known as impact ionization. When APDs work in the Geiger mode, due to the theoretically infinite magnification factor, APD can detect single-photon signal. However, compared with the design progress of APDs, life and reliability tests are rarely reported. In this paper, a method for assessing the reliability of silicon APDs is proposed, including the rapid estimation of APD fault activation energy (Ea), the analysis of APD failure mechanisms and assessment of lifetime. The operating life of the APDs is expected to be tens of thousands of hours. For such long-life devices, accelerated life testing is suitable for APDs. In a temperature stress test, in order to maintain the unity of the failure mechanism, temperature limit should be determined by monitoring dark current through a progressive stress test at first. Then another set of samples of the same structure was selected for step stress experiments.The test time and temperature interval were optimized using Arrhenius formula according to the stress limit and failure activation energy. Compared to 15,000h, the expected lifetime of our samples, the test time is greatly shortened, proving the high efficiency of our method. Fail occurs when extending the test time. The main cause of fail is the increase of surface leakage current, which will be verified in subsequent tests. Failure rate increases with time in wear out phase, and strongly depends on the structure of the device. Therefore, in addition to the assessment of lifetime, it is of great significance to improve the device design.