Lateral avalanche photodiode device and method of production

A lateral avalanche device comprises a semiconductor substrate (1) having a trench (4) with side walls (5) extending from a main surface (2) to a rear surface (3). A first doped region (11) is present at the side walls of the trench, and a second doped region (12) is arranged at a distance from the first doped region. A third doped region (13) is located adjacent to the first doped region, extends through the substrate from the main surface to the rear surface, and is arranged between the first doped region and the second doped region. The third doped region (13) is the avalanche multiplication region of the photodiode structure. The second doped region and the third doped region have a first type of conductivity, and the first doped region has a second type of conductivity which is opposite to the first type of conductivity. The region of the substrate that is between the first doped region and the second doped region is of the first type of conductivity.