A SEMICONDUCTOR DEVICE

According to a first example of the disclosure, a semiconductor device is proposed, which comprises a first layer doped with a first type of charge carriers; a second layer doped with a second type of charge carriers different from the first type of charge carriers; a third layer doped with the first type of charge carriers; a fourth layer doped with the second type of charge carriers; and an input terminal electrically connected with the first layer and an output terminal electrically connected with the fourth layer.The first, second and third layer form a first bipolar junction transistor, BJT, and the second, third and fourth layer form a second bipolar junction transistor, BJT. Additionally, a junction element is provided which electrically connects the second layer with the third layer. Furthermore, the third layer comprises a high dopant region adjoining the second layer.The electrical junction element functions as a short between the two base contacts of each BJT. It reduces the trigger voltage to the equivalent of two forward biased diodes. When the device gets triggered, both emitter base junctions, between the first-second layer and fourth-third layer, are forward biased at the same time. Injection of minority carriers starts from both sides and the turn-on effect is fast. At least one of the emitter base junctions has a low capacitance, therefore, the semiconductor controlled rectifier has a low capacitance, too.