High-Responsivity Si Photodiodes at 1060 nm in Standard CMOS Technology

Abstract

Photodetection with high responsivity at the wavelength of 1060 nm is highly desirable for light detection and ranging (LiDAR) as well as the recent emergence of swept-source optical coherent tomography (SS-OCT) applications. However, the absorption coefficient $\alpha $ of Si material at 1060 nm under the bias of 0 V is very low due to its approach to the absorption bandgap edge of Si material. In this letter, the carrier-collection-enhanced structure is proposed, which functions as multiple carrier collection paths, which enhances the external quantum efficiency of photodiodes. An efficient Si photodiode with responsivity of 0.49 A/W at 1060 nm at 0 V is demonstrated, which is 2.5 times of that of commercial products. The cost-effective fabrication of Si photodiodes greatly enhances the system performance of LiDAR and OCT.