An exemplary biosensor sensor for detecting the presence of a biological material includes an SOI substrate, a BJT formed on at least a portion of the substrate, and a sensing structure formed on at least a portion of an upper surface of the BJT. The BJT includes an emitter region, a collector region and a self-aligned epitaxially grown intrinsic base region laterally adjacent to the emitter and collector regions. The sensing structure includes an opening, centered above and exposing the intrinsic base region, and at least one dielectric layer formed in the opening and contacting at least a portion of the intrinsic base region. The dielectric layer is configured to respond to charges in biological molecules.

An exemplary biosensor sensor for detecting the presence of a biological material includes an SOI substrate, a BJT formed on at least a portion of the substrate, and a sensing structure formed on at least a portion of an upper surface of the BJT. The BJT includes an emitter region, a collector region and a self-aligned epitaxially grown intrinsic base region laterally adjacent to the emitter and collector regions. The sensing structure includes an opening, centered above and exposing the intrinsic base region, and at least one dielectric layer formed in the opening and contacting at least a portion of the intrinsic base region. The dielectric layer is configured to respond to charges in biological molecules.

Transistor structures and methods of fabricating transistor structures are provided. The methods include: fabricating a transistor structure at least partially within a substrate, the fabricating including: providing a cavity within the substrate; and forming a first portion and a second portion of the transistor structure at least partially within the cavity, the first portion being disposed at least partially between the substrate and the second portion, where the first portion inhibits diffusion of material from the second portion into the substrate. In one embodiment, the transistor structure is a field-effect transistor structure, and the first portion and the second portion include one of a source region or a drain region of the field-effect transistor structure. In another embodiment, the transistor structure is a bipolar junction transistor structure.

A lateral bipolar transistor includes trench emitter and trench collector regions to form ultra-narrow emitter regions, thereby improving emitter efficiency. The same trench process is used to form the emitter/collector trenches as well as the trench isolation structures so that no additional processing steps are needed to form the trench emitter and collector. In embodiments of the present invention, the trench emitter and trench collector regions may be formed using ion implantation into trenches formed in a semiconductor layer. In other embodiments, the trench emitter and trench collector regions may be formed by out-diffusion of dopants from heavily doped polysilicon filled trenches.

A manufacturing method of a semiconductor structure provides a substrate. A well having a first conductive type and a well having a second conductive type are formed in the substrate, respectively. A body region is formed in the well having the second conductive type. A first doped region and a second doped region are formed in the well having the first conductive type and the body region respectively. The first and second doped regions have same polarities, and a dopant concentration of the second doped region is higher than that of the first doped region. A third doped region is formed in the well having the second conductive type and between the first and second doped regions. The third and first doped regions have reverse polarities. A first field plate is formed on a surface region between the second and third doped regions.

A method of forming a semiconductor structure includes providing an emitter and a collector on a surface of an insulator layer. The emitter and the collector are spaced apart and have a doping of a first conductivity type. An intrinsic base is formed between the emitter and the collector and on the insulator layer by epitaxially growing the intrinsic base from at least a vertical surface of the emitter and a vertical surface of the collector. The intrinsic base has a doping of a second conductivity type opposite to the first conductivity type, and a first heterojunction exists between the emitter and the intrinsic base and a second heterojunction exists between the collector and the intrinsic base.

A bipolar junction transistor includes an intrinsic base formed on a substrate. The intrinsic base includes a superlattice stack including a plurality of alternating layers of semiconductor material. A collector and emitter are formed adjacent to the intrinsic base on opposite sides of the base. An extrinsic base structure is formed on the intrinsic base.

A semiconductor device includes a P-type semiconductor substrate, a plurality of N-type buried diffusion layers that are arranged in the semiconductor substrate, an N-type first semiconductor layer that is arranged in a first region on a first buried diffusion layer, an N-type second semiconductor layer that is arranged in a second region on a second buried diffusion layer, an N-type first impurity diffusion region that surrounds the first region in plan view, a P-type second impurity diffusion region that is arranged in the second semiconductor layer, an N-type third impurity diffusion region that is arranged in the second semiconductor layer, an N-type fourth impurity diffusion region that is arranged in the first semiconductor layer. The second region is a region in which an N-type impurity diffusion region that has a higher impurity concentration than the second semiconductor layer cannot be arranged.

We disclose a bi-directional bipolar junction transistor (BJT) structure, comprising: a base region of a first conductivity type, wherein said base region constitutes a drift region of said structure; first and second collector/emitter (CE) regions, each of a second conductivity type adjacent opposite ends of said base region; wherein said base region is lightly doped relative to said collector/emitter regions; the structure further comprising: a base connection to said base region, wherein said base connection is within or adjacent to said first collector/emitter region.

A semiconductor device includes a first conductivity type semiconductor substrate, a second conductivity type first and second buried diffusion layers that are arranged in the semiconductor substrate, a semiconductor layer arranged on the semiconductor substrate, a second conductivity type first impurity diffusion region that is arranged in the semiconductor layer, a second conductivity type second impurity diffusion region that is arranged, in the semiconductor layer, on the second buried diffusion layer, a second conductivity type first well that is arranged in a first region of the semiconductor layer, a first conductivity type second well that is arranged, in the semiconductor layer, in a second region, a first conductivity type third and fourth impurity diffusion regions that are arranged in the first well, and a first conductivity type fifth impurity diffusion region that is arranged in the second well.