Abstract: Methods for fabricating a heterojunction bipolar transistor having a raised extrinsic base is provided in which the base resistance is reduced by forming a silicide atop the raised extrinsic base that extends to the emitter region in a self-aligned manner. The silicide formation is incorporated into a BiCMOS process flow after the raised extrinsic base has been formed. The present invention also provides a heterojunction bipolar transistor having a raised extrinsic base and a silicide located atop the raised extrinsic base. The silicide atop the raised extrinsic base extends to the emitter in a self-aligned manner. The emitter is separated from the silicide by a spacer.

Abstract: A self-aligned oxide mask is formed utilizing differential oxidation rates of different materials. The self-aligned oxide mask is formed on a CVD grown base NPN base layer which compromises single crystal Si (or Si/SiGe) at active area and polycrystal Si (or Si/SiGe) on the field. The self-aligned mask is fabricated by taking advantage of the fact that poly Si (or Si/SiGe) oxidizes faster than single crystal Si (or Si/SiGe). An oxide film is formed over both the poly Si (or Si/siGe) and the single crystal Si (or Si/siGe) by using an thermal oxidation process to form a thick oxidation layer over the poly Si (or Si/siGe) and a thin oxidation layer over the single crystal Si (or Si/siGe), followed by a controlled oxide etch to remove the thin oxidation layer over the single crystal Si (or Si/siGe) while leaving the self-aligned oxide mask layer over the poly Si (or Si/siGe). A raised extrinsic base is then formed following the self-aligned mask formation.

Abstract: A bipolar vertical transistor is formed in a silicon semiconductor substrate which has an upper surface with STI regions formed therein composed of a dielectric material formed in the substrate having inner ends and top surfaces. A doped collector region is formed in the substrate between a pair of the STI regions. A counterdoped intrinsic base region is formed on the upper surface of the substrate between the pair of the STI regions with a margin between the intrinsic base region and the pair of STI regions, the intrinsic base region having edges. A doped emitter region is formed above the intrinsic base region spaced away from the edges. A shallow isolation extension region composed of a dielectric material is next to the edges of the intrinsic base region formed in the margin between the STI regions and the intrinsic base region.

Abstract: A self-aligned oxide mask is formed utilizing differential oxidation rates of different materials. The self-aligned oxide mask is formed on a CVD grown base NPN base layer which compromises single crystal Si (or Si/SiGe) at active area and polycrystal Si (or Si/SiGe) on the field. The self-aligned mask is fabricated by taking advantage of the fact that poly Si (or Si/SiGe) oxidizes faster than single crystal Si (or Si/SiGe). An oxide film is formed over both the poly Si (or Si/siGe) and the single crystal Si (or Si/siGe) by using an thermal oxidation process to form a thick oxidation layer over the poly Si (or Si/siGe) and a thin oxidation layer over the single crystal Si (or Si/siGe), followed by a controlled oxide etch to remove the thin oxidation layer over the single crystal Si (or Si/siGe) while leaving the self-aligned oxide mask layer over the poly Si (or Si/siGe). A raised extrinsic base is then formed following the self-aligned mask formation.

Abstract: A non-uniform depth base-emitter junction, with deeper junction at the lateral portions of the emitter, preferably coupled with a recessed and raised extrinsic base, bipolar transistor, and a method of making the same. The bipolar transistor includes a substrate, a silicon germanium layer formed on the substrate, a collector layer formed on the substrate, a recessed and raised extrinsic base layer formed on the silicon germanium layer, and a silicon pedestal on which an emitter layer is formed. The emitter has non-uniform depths into the base layer.

Abstract: A bipolar vertical transistor is formed in a silicon semiconductor substrate which has an upper surface with STI regions formed therein composed of a dielectric material formed in the substrate having inner ends and top surfaces. A doped collector region is formed in the substrate between a pair of the STI regions. A counterdoped intrinsic base region is formed on the upper surface of the substrate between the pair of the STI regions with a margin between the intrinsic base region and the pair of STI regions, the intrinsic base region having edges. A doped emitter region is formed above the intrinsic base region spaced away from the edges. A shallow isolation extension region composed of a dielectric material is next to the edges of the intrinsic base region formed in the margin between the STI regions and the intrinsic base region.

Abstract: A self-aligned oxide mask is formed utilizing differential oxidation rates of different materials. The self-aligned oxide mask is formed on a CVD grown base NPN base layer which compromises single crystal Si (or Si/SiGe) at active area and polycrystal Si (or Si/SiGe) on the field. The self-aligned mask is fabricated by taking advantage of the fact that poly Si (or Si/SiGe) oxidizes faster than single crystal Si (or Si/SiGe). An oxide film is formed over both the poly Si (or Si/siGe) and the single crystal Si (or Si/siGe) by using an thermal oxidation process to form a thick oxidation layer over the poly Si (or Si/siGe) and a thin oxidation layer over the single crystal Si (or Si/siGe), followed by a controlled oxide etch to remove the thin oxidation layer over the single crystal Si (or Si/siGe) while leaving the self-aligned oxide mask layer over the poly Si (or Si/siGe). A raised extrinsic base is then formed following the self-aligned mask formation.

Abstract: A non-uniform depth base-emitter junction, with deeper junction at the lateral portions of the emitter, preferably coupled with a recessed and raised extrinsic base, bipolar transistor, and a method of making the same. The bipolar transistor includes a substrate, a silicon germanium layer formed on the substrate, a collector layer formed on the substrate, a recessed and raised extrinsic base layer formed on the silicon germanium layer, and a silicon pedestal on which an emitter layer is formed. The emitter has non-uniform depths into the base layer.