Asymmetric transient voltage suppressor device and methods for formation
AssigneeLittelfuse, Inc.
InventorJames Allan Peters
Life of this patent
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Abstract
A transient voltage suppression (TVS) device, may include: a substrate base formed in a substrate, the substrate base comprising a semiconductor of a first conductivity type; and an epitaxial layer, disposed on the substrate base, on a first side of the substrate, and comprising a semiconductor of a second conductivity type. The epitaxial layer may include: a first portion, the first portion having a first layer thickness; and a second portion, the second portion having a second layer thickness, less than the first layer thickness, wherein the first portion and the second portion are disposed on a first side of the substrate, and wherein the first portion is electrically isolated from the second portion.
Claims18
A transient voltage suppression (TVS) device, comprising:
- a substrate base formed in a substrate, the substrate base comprising a semiconductor of a first conductivity type;
- and
- an epitaxial layer, disposed on the substrate base, on a first side of the substrate, and comprising a semiconductor of a second conductivity type, the epitaxial layer further comprising:
- a first portion, the first portion having a first layer thickness;
- and
- a second portion, the second portion having a second layer thickness, less than the first layer thickness, wherein the first portion and the second portion are disposed on a first side of the substrate, and wherein the first portion is electrically isolated from the second portion.
A transient voltage suppression (TVS) device assembly, comprising:
- a TVS device, the TVS device comprising:
- a substrate base formed in a substrate, the substrate base comprising a semiconductor of a first conductivity type;
- an epitaxial layer, disposed on the substrate base, on a first side of the epitaxial layer comprising a semiconductor of a second conductivity type, the epitaxial layer further comprising:
- a first portion, the first portion having a first layer thickness;
- and
- a second portion, the second portion having a second layer thickness, less than the first layer thickness, wherein the second portion comprises a trench shape, wherein a plane defined by a first upper surface of the first portion is above a second upper surface of the second portion;
- and
- a leadframe, the leadframe being coupled to the TVS device, the leadframe comprising:
- a first part, the first part being connected to the first portion of the TVS device;
- and
- a second part, the second part being coupled to the second portion of the TVS device.
A method, comprising:
- providing a substrate having a base layer of a first conductivity type;
- forming an epitaxial layer of a second conductivity type on the base layer, wherein the epitaxial layer is disposed on a first side of the substrate;
- forming a first epitaxial portion and a second epitaxial portion within the epitaxial layer, wherein the first epitaxial portion is electrically isolated from the second epitaxial portion;
- and
- forming a recess within the second epitaxial portion, wherein a first diode and a second diode are formed within the epitaxial layer on the first side of the substrate.
Dependencies are inferred from the claim text.