A bidirectional transient voltage suppressor with low dynamic resistance and high surge capability

Abstract

This invention provides a bidirectional transient voltage suppressor with low dynamic resistance and high surge capability, comprising: a heavily doped semiconductor substrate of a first conductivity type; a first epitaxial layer disposed on the substrate; a conduction modulation buried layer disposed on the first epitaxial layer; a second epitaxial layer disposed on the conduction modulation buried layer; a heavily doped first conductivity type region disposed on the second epitaxial layer; a first electrode disposed on the front side of the heavily doped first conductivity type region and a second electrode disposed on the back side of the substrate; the conduction modulation buried layer is disposed inside the double epitaxial body region and is configured to form a high-concentration conductivity modulation region of charge carriers under transient high current impact conditions, forming a body region-dominated conduction path between the first epitaxial layer and the second epitaxial layer, so that the conduction current changes from concentrated conduction in the PN junction region to a laterally extended and planar distributed overall conduction mode within the body region, thereby reducing the dynamic resistance of the device and improving the surge carrying capacity of the device.

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