Abstract: In accordance with the invention the semiconductor capacitor includes a first capacitor electrode 1, a second capacitor electrode 3 and a capacitor dielectric 5 which is arranged between the two capacitor electrodes and which includes praseodymium oxide. It is distinguished in that the second capacitor electrode 3 includes praseodymium silicide.

Abstract: A silicon-germanium hetero bipolar transistor comprising a silicon collector layer, a boron-doped silicon-germanium base layer, a silicon emitter layer and an emitter contact area. The transistor is fabricated using an epitaxy process on a surface of pure silicon. An electrically inert material is incorporated into the epitaxial layers in order to link the defects in the semiconductor structure and to reduce the outdiffusion of the dopant. Thus, a transistor for high-frequency applications can be fabricated in two ways: to increase the dopant dose of the base region or to reduce the thickness of the base layer. In particular, the concentration profile of germanium in the base layer has a general shape of a triangle or trapezoid.