A bipolar junction semiconductor device and associated method of manufacturing, the bipolar junction semiconductor device has a P type substrate, a N type buried layer formed in the substrate, a P type first epitaxial layer formed on the buried layer, a P type second epitaxial layer formed on the first epitaxial layer, a PNP BJT unit formed in the first and second epitaxial layers at a first active area, a NPN BJT unit formed in the first and second epitaxial layers at a second active area and a first isolation structure of N type formed in the first and second epitaxial layers at an isolation area. The isolation area is located between the first active area and the second active area, the first isolation structure connected with the buried layer forms an isolation barrier.

Semiconductor power devices can be formed on substrate structure having a lightly doped semiconductor substrate of a first conductivity type or a second conductivity type opposite to the first conductivity type. A semiconductive first buffer layer of the first conductivity type formed above the substrate. A doping concentration of the first buffer layer is greater than a doping concentration of the substrate. A second buffer layer of the second conductivity type formed above the first buffer layer. An epitaxial layer of the second conductivity type formed above the second buffer layer. One or more heavily doped regions of the second conductivity type are formed through portions of the first buffer layer from the second buffer layer and into corresponding portions of the substrate. This abstract is provided with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

A method of manufacturing a silicon carbide (SiC) bipolar junction transistor (BJT) and a SiC BJT (100) are provided. The SiC BJT comprises an emitter region (150), a base region (140) and a collector region (120). The collector region is arranged on a substrate (110) having an off-axis orientation of about 8 degrees or lower. A defect termination layer (DTL, 130) for terminating dislocations originating from the substrate is arranged between the substrate and the collector region. The collector region includes a zone (125) in which the life time of the minority charge carriers is shorter than in the base region. The present invention is advantageous in terms of improved stability of the SiC BJTs.