Single photon avalanche diode

The utility model provides a single photon avalanche diode. The single photon avalanche diode comprises an N-type semiconductor well layer, a P-type semiconductor well layer and a P-type side doping layer. The P-type semiconductor well layer is disposed on the N-type semiconductor well layer. The P-type side doped layer is disposed between the N-type semiconductor well layer and the P-type semiconductor well layer. The depth of the P-type side doping layer is smaller than that of the P-type semiconductor well layer. The P-type doping concentration of the P-type side doping layer is greater than the P-type doping concentration of the P-type semiconductor well layer. 本实用新型提供一种单光子雪崩二极管，包括N型半导体井层、P型半导体井层以及P型侧掺杂层。P型半导体井层配置于N型半导体井层上。P型侧掺杂层配置于N型半导体井层与P型半导体井层之间。P型侧掺杂层的深度小于P型半导体井层的深度。P型侧掺杂层的P型掺杂浓度大于P型半导体井层的P型掺杂浓度。