D. Hill, J. Zhu, W. Chan, S. Griggs, N. Park
Keywords: LIDAR, GmAPD, Geiger mode, avalanche photodiode, direct detection, coherent detection, laser communication, photon counting, InP
Summary:Advancements in electronic chip functionality require architectures that go beyond singular layers of Si-based electronics. Infrared imaging, in particular, requires a fusion between conventional silicon electronics and other materials, such as InP, to expand detection wavelengths beyond the bandgap of silicon. We will describe advancements in the production of InP-based Geiger-mode avalanche photodiode (APD) arrays for lidar and single-photon-sensitive imaging applications, design constraints and considerations, and the future of APD technology. The high sensitivity, low dark count rate, and fine pixel pitch of these detectors enables photon counting performance without cryogenic cooling. Control of and data extraction from each of these pixels, however, requires direct integration with Si read-out electronics. We will discuss the current hybridization approaches, limitations of the state of the art, and the benefits and challenges of applying new 3D heterogenous integration techniques to these systems to improve operation and integrate new functionality into the chip stack.