Study of Au doping processing for high quality extrinsic doped n on p HgCdTe detector

Au, the most pivotal dopant in n-on-p HgCdTe technology, exhibits intricate interactions with Hg vacancy. Understanding this interaction is essential for the fabrication of Au-doped HgCdTe infrared detectors. In this study, we examined the diffusion properties of Au atoms in vacancy-doped HgCdTe utilizing secondary ion mass spectrometry and variable-temperature Hall measurements. The results indicate that Au atoms in interstitial sites rapidly diffuse into HgCdTe, continuing until they occupy vacancy sites and act as acceptors. Infrared detectors doped with Au via this approach exhibited an order of decrease in the dark current density compared to vacancy-doped counterparts, suggesting that Au atoms almost occupy Hg vacancies, achieving effective incorporation.