Fabrication of 64×64 InGaAs/InP avalanche photodiode (APD) focal plane arrays

Abstract

In this study, the fabrication of the 64×64 InGaAs/InP avalanche photodiode （APD）focal plane arrays for single photon detection in the near-infrared region (0.9~1.65 μm) was conducted. The APD is with a separate absorption, grading, charge, and multiplication (SAGCM) structure. The structure and material parameters of the epitaxy layers and the electrodes were described in detail. Backside illumination mesa structure arrays are successfully created. Sample with surface SiNx layer with the thickness of 200 nm is found have higher light response. The electrical properties tested indicate that the quality of the APD arrays is uniform, and the signal to noise ratio (SNR) is in a very low level, which meet the image sensing requirement. Indium bumps, which was used for flip-chip micro-array was found with good shape after the deposition and reflow processes.