Abstract: A Geiger mode planar InGaAs/InP avalanche photodiode (APD) with a cascade peripheral junction structure to suppress edge breakdowns is designed by finite-element analysis.The photodiode breakdown voltage is reduced to 54.3V by controlling the central junction depth,while the electric field distribution along the device central axis is controlled by adjusting doping level and thickness of the InP field control layer.Using a cascade junction structure at the periphery of the active area,premature edge breakdowns are effectively suppressed.The simulations show that the quadra-cascade structure is a good trade-off between suppression performance and fabrication complexity,with a reduced peak electric field of 5.2E5kV/cm and a maximum hole ionization integral of 1.201.Work presented in this paper provides an effective way to design high performance photon counting InGaAs/InP avalanche photodiodes.

Key words: Geiger mode APD, edge breakdown, cascade junction, breakdown voltage