Abstract: Some spin tunnel transistors with a larger current transmittance and a higher MR ratio are described. One of the spin tunnel transistor comprises a collector; an emitter; abase formed between the collector and the emitter, including a first ferromagnetic metal layer variable in its magnetization under an external magnetic field; a barrier layer formed between the first ferromagnetic metal layer and one of the collector and the emitter, the other of the collector and the emitter including a semiconductor crystal layer; and a transition metal silicide crystal layer between the semiconductor crystal layer and the base. The transition metal silicide crystal layer may be replaced with a palladium layer, a transition metal nitride layer, or a transition metal carbide layer.

Abstract: A material made by arranging layers of gallium-arsenide-antimonide (GaAsxSb1-x, 0.0?x?1.0) and/or indium-gallium-arsenic-nitride (InyGa1-yAszN1-z, 0.0?y, z?1.0) in a specific order is used to form the transistor base of a heterojunction bipolar transistor. By controlling the compositions of the materials indium-gallium-arsenic-nitride and gallium-arsenide-antimonide, and by changing the thickness and order of the layers, the new material would possess a specific energy gap, which in turn determines the base-emitter turn-on voltage of the heterojunction bipolar transistor.

Abstract: A method and system for providing a bipolar transistor is described. The method and system include providing a compound base region, providing an emitter region coupled with the compound base region, and providing a collector region coupled with the compound base region. The bipolar transistor may also include at least one other predetermined portion. The method and system also include providing at least one predetermined amount of oxygen to at least one of the compound base region, the emitter region, the collector region, and the predetermined portion of the bipolar transistor.

Abstract: A SiGe heterojunction bipolar transistor including at least an emitter formed on a SiGe base region wherein the sidewalls of the emitter are protected by a conformal passivation layer. The conformal passivation layer is formed on the exposed sidewalls of said emitter prior to siliciding the structure. The presence of the passivation layer in the structure prevents silicide shorts from occurring by eliminating bridging between adjacent silicide regions; therefore improved SiGe bipolar yield is obtained. A method for forming such a structure is also provided.

Abstract: Apparatus comprising: a first compound semiconductor composition layer doped to have a first charge carrier polarity; a second compound semiconductor composition layer doped to have a second charge carrier polarity and located on the first layer; a third compound semiconductor composition layer doped to have the first charge carrier polarity and located on the second layer; a base electrode on the second layer; and a spacer ring interposed between and defining a charge carrier access path distance between the base electrode and the third layer, the path distance being within a range of between about 200 ? and about 1000 ?. Techniques for making apparatus. Apparatus is useful as a heterobipolar transistor, particularly for high frequency applications.

Abstract: A bipolar transistor includes a Si single crystalline layer serving as a collector, a single crystalline Si/SiGeC layer and a polycrystalline Si/SiGeC layer which are formed on the Si single crystalline layer, an oxide film having an emitter opening portion, an emitter electrode, and an emitter layer. An intrinsic base layer is formed on the single crystalline Si/SiGeC layer, part of the single crystalline Si/SiGeC layer, the polycrystalline Si/SiGeC layer and the Co silicide layer together form an external base layer. The thickness of the emitter electrode is set so that boron ions implanted into the emitter electrode and diffused therein do not reach an emitter-base junction portion.

Abstract: A semiconductor structure having a self-aligned base contact and an emitter, where the base contact is electrically isolated from the emitter by a dielectric layer. The separation between the base contact and the emitter is determined by the thickness of the dielectric layer and the width of the emitter is determined by the minimum resolution provided by the fabrication techniques and tools used to define features within the dielectric layer.