Schottky diode and method for fabricating the same

摘要

A Schottky diode includes a deep well formed in a substrate, an isolation layer formed in the substrate, a first conductive type guard ring formed in the deep well along an outer sidewall of the isolation layer and located at a left side of the isolation layer, a second conductive type well formed in the deep well along the outer sidewall of the isolation layer and located at a right side of the isolation layer, an anode electrode formed over the substrate and coupled to the deep well and the guard ring, and a cathode electrode formed over the substrate and coupled to the well. A part of the guard ring overlaps the isolation layer.

主权项

1. A Schottky diode comprising:
a deep well in a substrate; an isolation layer in the substrate; a guard ring of a first conductive type in the deep well comprising a first region and a second region and located at one side of the isolation layer; a well region of a second conductive type in the deep well and located at an opposite side of the isolation layer; a first electrode over the substrate and coupled to the deep well and the guard ring; and a second electrode over the substrate and coupled to the well region, wherein the first region of the guard ring overlaps with the isolation layer and the second region of the guard ring does not overlap with the isolation layer, wherein a width of a top surface of the first region is different from a width of a top surface of the second region, and wherein the well region comprises: a third impurity region having a third doping concentration being in contact with the second electrode; a second impurity region having a second doping concentration below the third impurity region; and a first impurity region having a first doping concentration below the second impurity region, wherein the third doping concentration is greater than the first doping concentration.