TVS WITH LOW CAPACITANCE & FORWARD VOLTAGE DROP WITH DEPLETED SCR AS STEERING DIODE

摘要

A transient-voltage suppressing (TVS) device disposed on a semiconductor substrate of a first conductivity type. The TVS includes a buried dopant region of a second conductivity type disposed and encompassed in an epitaxial layer of the first conductivity type wherein the buried dopant region extends laterally and has an extended bottom junction area interfacing with the underlying portion of the epitaxial layer thus constituting a Zener diode for the TVS device. The TVS device further includes a region above the buried dopant region further comprising a top dopant layer of a second conductivity type and a top contact region of a second conductivity type which act in combination with the epitaxial layer and the buried dopant region to form a plurality of interfacing PN junctions constituting a SCR acting as a steering diode to function with the Zener diode for suppressing a transient voltage.

主权项

1. A transient voltage suppressing (TVS) device comprising:
a semiconductor substrate of a first conductivity type; an epitaxial layer of the first conductivity type disposed on top of said semiconductor substrate and a top dopant layer of a second conductivity type disposed at the top of said epitaxial layer; a buried dopant region of the second conductivity type disposed and encompassed in the epitaxial layer wherein said buried dopant region interfacing with underlying portions of said epitaxial layer thus constituting a Zener diode for said TVS device; and a first contact region of the first conductivity type disposed at the top of said top dopant layer over said buried dopant region for constituting a semiconductor controlled rectifier (SCR) functioning as a first steering diode, wherein said SCR comprises vertically of the first contact region, the top dopant layer, the epitaxial layer, and the buried dopant region.