Abstract: An integrated circuit structure comprises a body of semiconductor material and first and second transistors formed in a surface region of the body. The body of semiconductor material comprises a substrate of silicon doped with a p-type impurity and an epitaxial layer of silicon over predetermined surface regions of the substrate. The epitaxial layer is of substantially uniform thickness. Each transistor comprises a base, an emitter and an active collector formed in the epitaxial layer, and a subcollector formed in the substrate and extending beneath the base and the active collector of the transistor. The second transistor comprises, in addition, a contact collector formed in the epitaxial layer and laterally spaced from the base and the emitter of the second transistor.