A bipolar semiconductor device and manufacturing method. One embodiment provides a diode structure including a structured emitter coupled to a first metallization is provided. The structured emitter includes a first weakly doped semiconductor region of a first conductivity type which forms a pn-load junction with a weakly doped second semiconductor region of the diode structure. The structured emitter includes at least a highly doped first semiconductor island of the first conductivity type which at least partially surrounds a highly doped second semiconductor island of the second conductivity type.