Trench Schottky barrier diode and manufacturing method thereof

摘要

The present invention discloses a trench Schottky barrier diode (SBD) and a manufacturing method thereof. The trench SBD includes: an epitaxial layer, formed on a substrate; multiple mesas, defined by multiple trenches; a field plate, formed on the epitaxial layer and filled in the multiple trenches, wherein a Schottky contact is formed between the field plate and top surfaces of the mesas; a termination region, formed outside the multiple mesas and electrically connected to the field plate; a field isolation layer, formed on the upper surface and located outside the termination region; and at least one mitigation electrode, formed below the upper surface outside the termination region, and is electrically connected to the field plate through the field isolation layer, wherein the mitigation electrode and the termination region are separated by part of a dielectric layer and part of the epitaxial layer.

主权项

1. A trench Schottky barrier diode (SBD) formed on a first conductive type substrate, comprising:
a first conductive type substrate; a second conductive type epitaxial layer, which is formed on the substrate; a plurality of mesas, which are formed by etching the epitaxial layer from an upper surface of the epitaxial layer downward, wherein the etching of the epitaxial layer forms plural trenches; a dielectric layer, which is formed on side walls and bottoms of the plural trenches; a field plate, which is formed on the epitaxial layer and filled in the plural trenches, wherein the dielectric layer separates the field plate from the side walls and bottoms of the plural trenches, and a Schottky contact is formed between the field plate and top surfaces of the plural mesas; a termination region, which is formed outside an edge of the plural mesas and below the upper surface of the epitaxial layer, and is electrically connected to the field plate, wherein the dielectric layer separates the termination region from the epitaxial layer and the edge; a field isolation layer, which is formed on the upper surface of the epitaxial layer, and is located outside the termination region; and at least one mitigation electrode, which is formed below the upper surface of the epitaxial layer and outside the termination region, wherein the field plate is electrically connected to the at least one mitigation electrode through the field isolation layer, and wherein the mitigation electrode and the termination region are separated by part of the dielectric layer and part of the epitaxial layer.