Abstract: A single-photon avalanche diode (SPAD) is disclosed. In one aspect, the SPAD comprises an inner doped region, a geometrical structure of a boundary of the inner doped region rotationally symmetric in a horizontal direction of a substrate; at least one outer doped region connected to a second terminal, the at least one outer doped region arranged to at least partially enclose the inner doped region and the outer doped region comprising dopant implantations of a different type than the inner doped region; a lowly doped depletion volume arranged to surround the inner doped region, a depth of the lowly doped depletion volume extending from the top surface of the substrate into the substrate being larger than a depth of the at least one outer doped region, and when a reverse bias is applied to an anode, an electric field peak around the inner doped region being formed to enable impact ionization and multiplication of charges.

Abstract: Example embodiments relate to single-photon avalanche diode detector (SPAD) arrays. One embodiment includes a SPAD array that includes a silicon substrate, a plurality of primary electrodes, and a plurality of secondary electrodes. Each of the primary electrodes includes a semiconductor material of a first doping type, extends in the silicon substrate in a first direction, and has a rotationally symmetric cross-section in a first plane perpendicular to the first direction. The plurality of secondary electrodes includes a semiconductor material of a second doping type and extends parallel to the primary electrodes in the silicon substrate. Further, the silicon substrate includes a doped upper field redistribution layer, a doped lower field redistribution layer, and a doped depletion layer arranged between the upper field redistribution layer and the lower field redistribution layer.

Abstract: A single-photon avalanche diode (SPAD) is disclosed. In one aspect, the SPAD comprises an inner doped region, a geometrical structure of a boundary of the inner doped region rotationally symmetric in a horizontal direction of a substrate; at least one outer doped region connected to a second terminal, the at least one outer doped region arranged to at least partially enclose the inner doped region and the outer doped region comprising dopant implantations of a different type than the inner doped region; a lowly doped depletion volume arranged to surround the inner doped region, a depth of the lowly doped depletion volume extending from the top surface of the substrate into the substrate being larger than a depth of the at least one outer doped region, and when a reverse bias is applied to an anode, an electric field peak around the inner doped region being formed to enable impact ionization and multiplication of charges.

Abstract: Example embodiments relate to single-photon avalanche diode detector (SPAD) arrays. One embodiment includes a SPAD array that includes a silicon substrate, a plurality of primary electrodes, and a plurality of secondary electrodes. Each of the primary electrodes includes a semiconductor material of a first doping type, extends in the silicon substrate in a first direction, and has a rotationally symmetric cross-section in a first plane perpendicular to the first direction. The plurality of secondary electrodes includes a semiconductor material of a second doping type and extends parallel to the primary electrodes in the silicon substrate. Further, the silicon substrate includes a doped upper field redistribution layer, a doped lower field redistribution layer, and a doped depletion layer arranged between the upper field redistribution layer and the lower field redistribution layer.