Integrated schottky diode using buried power buss structure and method for making same
View Patent ↗An integrated Schottky diode and method of manufacture of such a diode is disclosed. In a first aspect, a Schottky diode comprises a semiconductor substrate. The semiconductor substrate includes an epitaxial layer (EPI) on the substrate region. The diode includes a plurality of guard rings in the EPI layer and a plurality of oxidized slots. Finally, the diode includes metal within the plurality of slots to form a Buried Power Buss. A portion of the metal is completely oxide isolated from the other elements of the diode. In a second aspect, a method for manufacturing a Schottky diode comprises providing a substrate region, A buried N+ region providing an epitaxial (EPI) layer. The method also includes providing a plurality of guard rings in the EPI layer and providing a plurality of slots in the semiconductor substrate that is in contact with the EPI layer and the substrate region. The method further includes a plurality of oxidizing the slots and providing metal within the plurality of slots to form a Buried Power Buss structure. A portion of the metal is completely oxide isolated from the other elements of the diode. Accordingly, the system and method in accordance with the present invention a Schottky diode is provided that has low forward drop, low leakage at low and high voltages, and has a high reverse breakdown voltage.
1. A method for providing an integrated Schottky diode comprising:
(a) providing a substrate region;
(b) providing epitaxial (EPI) layer on the substrate region;
(c) providing a plurality of guard rings in the EPI layer;
(d) providing a plurality of slots in a substrate region that is in contact with the EPI layer in the substrate region;
(e) oxidizing the plurality of slots; and
(f) providing a plurality of metals within the plurality of slots to form a buried power buss, wherein a portion of the plurality of metals is completely oxide isolated from the other elements of the diode, wherein the plurality of metals comprises three deposited metals, wherein first and second metal depositions fill the plurality of slots followed by a deposited dielectric, wherein the deposited dielectric has contacts opened above the plurality of slots and a third deposited metal provides an interconnect layer wherein a third metal forms the interconnecting metal to circuit elements and a second deposited metal, and is oxide isolated from a remaining portion of Schottky diode, wherein the integrated Schottky diode has a high reverse voltage, low forward drop, low leakage and of limited capacitance.
2. The method of claim 1 wherein the guard ring is reduced due to the buried power buss.
3. The method of claim 1 wherein a buried layer is provided between the substrate region and the EPI layer.
4. A Schottky diode comprising:
a substrate region;
an epitaxial layer (EPI) on the substrate region;
a plurality of guard rings in the EPI layer;
a plurality of oxidized slots; and
metal within the plurality of oxidized slots to form a buried power buss, wherein a portion of the metal is completely oxide isolated from other elements of the diode, wherein the plurality of metals comprises three deposited metals, wherein first and second metal depositions fill the plurality of slots followed by a deposited dielectric, wherein the dielectric has contacts opened above the plurality of slots, wherein a third deposited metal provides the metal for the Schottky structure, as well as an interconnect layer, wherein the third deposited metal forms the contacts to a circuit and the second deposited metal, and is oxide isolated from a remaining portion of the Schottky diode, wherein the diode has a high reverse voltage, low forward drop, low leakage and of limited capacitance.
5. The Schottky diode of claim 4 wherein the guard ring is reduced due to the buried power buss cutting off a large portion of the guard ring area.
6. The Schottky diode of claim 4 wherein a buried layer is provided between the substrate region and the EPI layer.