Bipolar transistor having high emitter efficiency
First Claim
1. A bipolar transistor with high emitter efficiency in an integrated circuit semiconductor device, the transistor comprising;
- a substrate;
a collector region of a first conductivity type supported by the substrate;
a base region of a second conductivity type supported above the substrate in a PN-junction-forming relationship with the collector region; and
an emitter supported above the substrate in a PN-junction-forming relationship with the base region on a face of the base region opposite from the collector region;
wherein the emitter includes a monocrystalline semiconductor region of the first conductivity type at the base-emitter PN-junction, a polycrystalline semiconductor layer of the first conductivity type spaced from the monocrystalline emitter region, and a tunneling barrier layer interposed between and in contact with the monocrystalline region and polycrystalline layer, the tunneling barrier layer having a thickness of about 100 to 200 angstroms and an energy band gap in the range of about 1.8 to 3.5 eV.
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Accused Products
Abstract
A vertical conduction NPN bipolar transistor with a tunneling barrier of silicon carbide in the emitter providing a high emitter injection efficiency and high, stable current gain. The emitter structure comprises a heavily doped polysilicon layer atop a silicon carbide layer that contacts a shallow, heavily doped emitter region at the surface of an epitaxial silicon layer, which is disposed on a monocrystallinie silicon substrate. The silicon carbide layer is about 100 to 200 angstroms thick and has a composition selected to provide an energy band gap in the 1.8 to 3.5 eV range. The thickness and composition of the silicon carbide can be varied within the preferred ranges to tune the transistor'"'"'s electrical characteristics and simplify the fabrication process.
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Citations
20 Claims
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1. A bipolar transistor with high emitter efficiency in an integrated circuit semiconductor device, the transistor comprising;
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a substrate; a collector region of a first conductivity type supported by the substrate; a base region of a second conductivity type supported above the substrate in a PN-junction-forming relationship with the collector region; and an emitter supported above the substrate in a PN-junction-forming relationship with the base region on a face of the base region opposite from the collector region; wherein the emitter includes a monocrystalline semiconductor region of the first conductivity type at the base-emitter PN-junction, a polycrystalline semiconductor layer of the first conductivity type spaced from the monocrystalline emitter region, and a tunneling barrier layer interposed between and in contact with the monocrystalline region and polycrystalline layer, the tunneling barrier layer having a thickness of about 100 to 200 angstroms and an energy band gap in the range of about 1.8 to 3.5 eV. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A bipolar transistor with high emitter efficiency in an integrated circuit semiconductor device, the transistor comprising;
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a substrate; a collector region of a first conductivity type supported by the substrate; a base region of a second conductivity type supported above the substrate in a PN-junction-forming relationship with the collector region; and an emitter supported above the substrate in a PN-junction-forming relationship with the base region on a face of the base region opposite from the collector region; wherein the emitter includes a monocrystalline semiconductor region of the first conductivity type at the base-emitter PN-junction, a polycrystalline semiconductor layer of the first conductivity type spaced from the monocrystalline emitter region, and a tunneling barrier layer interposed between and in contact with the monocrystalline region and polycrystalline layer, the tunneling barrier layer consisting essentially of silicon carbide and having a thickness of about 100 to 200 angstroms. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A bipolar transistor with high emitter efficiency in an integrated circuit semiconductor device, the transistor comprising;
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a substrate; a collector region of a first conductivity type supported by the substrate; a base region of a second conductivity type supported above the substrate in a PN-junction-forming relationship with the collector region; and an emitter supported above the substrate in a PN-junction-forming relationship with the base region on a face of the base region opposite from the collector region; wherein the emitter includes a monocrystalline semiconductor region of the first conductivity type at the base-emitter PN junction, a polycrystalline semiconductor layer of the first conductivity type spaced from the monocrystalline emitter region, and a tunneling barrier layer interposed between and in contact with the monocrystalline region and polycrystalline layer, the tunneling barrier layer consisting essentially of silicon carbide and having a composition selected to provide an energy band gap in the range of about 1.8 to 3.5 eV. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
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Specification