Electrostatic discharge protection device in integrated circuit
First Claim
1. An electrostatic discharge protection device of a semiconductor integrated circuit comprising a bipolar transistor, comprising:
- a semiconductor substrate of a first conductivity type;
a first diffusion layer that is a diffusion layer of a second conductivity type provided on the semiconductor substrate and serves as a collector;
a second diffusion layer that is a diffusion layer of the first conductivity type provided in the first diffusion layer and serves as a base;
a third diffusion layer that is a diffusion layer of the second conductivity type provided in the second diffusion layer and serves as an emitter;
a collector contact region provided in the first diffusion layer;
a fourth diffusion layer that is a diffusion layer of the second conductivity type provided in the first diffusion layer in a downward region of the collector contact region in a substrate-thickness direction, wherein the fourth diffusion layer is formed shallower in a depth than that of the first diffusion layer in the substrate-thickness direction, deeper in a depth than that of the second diffusion layer in the substrate-thickness direction and with a higher density than that of the first diffusion layer; and
an insulation film formed on a surface of the first diffusion layer between the second diffusion layer and the collector contact region and serving as a field, whereinthe fourth diffusion layer is extended up until a region below the insulation film.
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Abstract
An electrostatic discharge protection device of a semiconductor integrated circuit, comprising a first diffusion layer that is a diffusion layer of a second conductivity type provided on a semiconductor substrate of a first conductivity type and serves as a collector, a second diffusion layer that is a diffusion layer of the first conductivity type provided in the first diffusion layer and serves as a base, a third diffusion layer that is a diffusion layer of the second conductivity type provided in the second diffusion layer and serves as an emitter, a collector contact region provided in the first diffusion layer, a fourth diffusion layer that is a diffusion layer of the second conductivity type provided in the first diffusion layer in a downward region of the collector contact region in a substrate-thickness direction, wherein the fourth diffusion layer is formed shallower in a depth than that of the first diffusion layer in the substrate-thickness direction, deeper in a depth than that of the second diffusion layer in the substrate-thickness direction and with a high density than that of the first diffusion layer, and an insulation film formed on a surface of the first diffusion layer between the second diffusion layer and the collector contact region and serving as a field, wherein the fourth diffusion layer is extended up until a region below the insulation film.
28 Citations
7 Claims
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1. An electrostatic discharge protection device of a semiconductor integrated circuit comprising a bipolar transistor, comprising:
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a semiconductor substrate of a first conductivity type; a first diffusion layer that is a diffusion layer of a second conductivity type provided on the semiconductor substrate and serves as a collector; a second diffusion layer that is a diffusion layer of the first conductivity type provided in the first diffusion layer and serves as a base; a third diffusion layer that is a diffusion layer of the second conductivity type provided in the second diffusion layer and serves as an emitter; a collector contact region provided in the first diffusion layer; a fourth diffusion layer that is a diffusion layer of the second conductivity type provided in the first diffusion layer in a downward region of the collector contact region in a substrate-thickness direction, wherein the fourth diffusion layer is formed shallower in a depth than that of the first diffusion layer in the substrate-thickness direction, deeper in a depth than that of the second diffusion layer in the substrate-thickness direction and with a higher density than that of the first diffusion layer; and an insulation film formed on a surface of the first diffusion layer between the second diffusion layer and the collector contact region and serving as a field, wherein the fourth diffusion layer is extended up until a region below the insulation film. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification