Stmicroelectronics S.a.

Emmanuel Collard

Patrick Poveda

Jean-Luc Morand

André Lhorte

Andr&eacute; Lhorte

A vertical rectifying and protection power diode, formed in a lightly-doped semiconductor layer of a first conductivity type, resting on a heavily-doped substrate of the first conductivity type, having a first ring-shaped region, of the first conductivity type more heavily-doped than the layer and more lightly doped than the substrate, surrounding an area of the layer and extending to the substrate; and a second ring-shaped region, doped of the second conductivity type, extending at the surface of the first region and on either side thereof; a first electrode having a thin layer of a material capable of forming a Schottky diode with the layer, resting on the area of the layer and on at least a portion of the second ring-shaped region with which it forms an ohmic contact.

Rectifying and protection diode

A vertical diode of low capacitance formed in a front surface of a semiconductor substrate, including a first area protruding from the substrate surface including at least one doped semiconductor layer of a conductivity type opposite to that of the substrate, the upper surface of the semiconductor layer supporting a first welding ball. The diode includes a second area including on the substrate a thick conductive track supporting at least two second welding balls, said first and second welding balls defining a plane parallel to the substrate plane.

Low-capacity vertical diode

The invention concerns a low-capacity vertical diode designed to be mounted by a front surface made in a semiconductor substrate (), comprising a first zone projecting relative to the surface of the substrate including at least a semiconductor layer () doped with a type of conductivity opposite to that of the substrate, the upper surface of the semiconductor layer bearing a first solder bump (). The diode comprises a second zone including on the substrate a thick strip conductor () bearing at least second solder bumps (), said first and second solder bumps defining a plane parallel to the substrate plane.

The invention concerns a method for making a vertical Schottky diode on a highly doped N-type silicon carbide substrate (), comprising steps which consist in forming an N-type lightly doped epitaxial layer (); etching out a peripheral trench at the active zone of the diode; forming a type P doped epitaxial layer; carrying out a planarization process so that a ring () of the P type epitaxial layer remains in the trench; forming an insulating layer () on the outer periphery of the component, said insulating layer partly covering said ring; and depositing a metal () capable of forming a Schottky barrier with the N type epitaxial layer.

Method for producing a schottky diode in silicon carbide

A vertical Schottky diode including an N-type silicon carbide layer of low doping level formed by epitaxy on a silicon carbide substrate of high doping level. The periphery of the active area of the diode is coated with a P-type epitaxial silicon carbide layer. A trench crosses the P-type epitaxial layer and penetrates into at least a portion of the height of the N-type epitaxial layer beyond the periphery of the active area. The doping level of the P-type epitaxial layer is chosen so that, for the maximum voltage that the diode is likely to be subjected to, the equipotential surfaces corresponding to approximately &frac14; to &frac34; of the maximum voltage extend up to the trench.

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Tours, France

Emmanuel Collard