Abstract: In a semiconductor device having a plurality of semiconductor layers of different composition, such as a hot electron transistor, in which respective layers are contacted to form a majority carrier injection electrode, a control electrode and a majority carrier extraction electrode, the layers forming the electrodes are separated from one another by separating layers or layer systems of different composition. These separating layers form potential barriers for the majority carriers. A problem with such known devices is that the layer forming the control electrode has to have a low resistance which has previously required a high doping concentration in this layer. This doping concentration however increases losses due to plasmon/phonon coupling and scattering and reduces the switching speed of the device.