Abstract: A high-frequency bipolar transistor structure includes a base region of a first conductivity type formed in a silicon layer of a second conductivity type, the base region comprising an intrinsic base region surrounded by an extrinsic base region, an emitter region of the second conductivity type formed inside the intrinsic base region, the extrinsic base region and the emitter region being contacted by a first polysilicon layer and a second polysilicon layer respectively. The first and the second polysilicon layers are respectively contacted by a base metal electrode and an emitter metal electrode. Between the extrinsic base region and the first polysilicon layer, a silicide layer is provided to reduce the extrinsic base resistance of the bipolar transistor.

Abstract: A high-frequency bipolar transistor structure includes a base region of a first conductivity type formed in a silicon layer of a second conductivity type, the base region comprising an intrinsic base region surrounded by an extrinsic base region, an emitter region of the second conductivity type formed inside the intrinsic base region, the extrinsic base region and the emitter region being contacted by a first polysilicon layer and a second polysilicon layer respectively. The first and the second polysilicon layers are respectively contacted by a base metal electrode and an emitter metal electrode. Between the extrinsic base region and the first polysilicon layer, a silicide layer is provided to reduce the extrinsic base resistance of the bipolar transistor.

Abstract: A high-frequency lateral PNP transistor includes a base region laterally delimited by P type emitter and collector regions, and at the top by a surface portion of the N type semiconductor body housing the active area of the transistor. The surface portion delimiting the base region presents no formations of insulating material grown across the surface, so that the width (W.sub.B) of the base region is reduced and ensures optimum dynamic characteristics of the transistor. The base contact may be located directly over the surface portion facing the base region, to reduce the extrinsic base resistance and overall size of the device, or it may be located remotely and connected to the base region by a buried layer and sinker region to further reduce the base width.