US 2006/0220166 A1Published application

Semiconductor device

AssigneeSanyo Electric Co., Ltd.

InventorsShuichi Kikuchi, Shigeaki Okawa, Kiyofumi Nakaya, Toshiyuki Takahashi

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Abstract

In a semiconductor device of the present invention, a protection diode for protecting a device is formed on an epitaxial layer formed on a substrate. A Schottky barrier metal layer is formed on a surface of the epitaxial layer and a P-type diffusion layer is formed at a lower portion of an end portion of the Schottky barrier metal layer. Then, a P-type diffusion layer is formed to be connected to a P-type diffusion layer and is extended to a cathode region. A metal layer to which an anode electrode is applied is formed above the P-type diffusion layer, thereby making it possible to obtain a field plate effect. This structure reduces a large change in a curvature of a depletion layer, thereby improving a withstand voltage characteristic of the protection diode.

Claims8

Dependent claims

A semiconductor device comprising:

first and second anode diffusion layers of opposite conductivity types formed on a semiconductor layer of one conductivity type to be isolated therefrom;
a cathode diffusion layer of one conductivity type formed on the semiconductor layer;
a third anode diffusion layer of an opposite conductivity type formed on the semiconductor layer to be connected to the second anode diffusion layer, and extended to the cathode diffusion layer:
an insulation layer formed on a top surface of the semiconductor layer;
and
an anode electrode connected to the first and second anode diffusion layers through a contact hole formed on the insulation layer, and forms a Schottky junction with the semiconductor layer between the first anode diffusion layer and the second anode diffusion layer,
wherein at least one of the anode electrode and a metal layer connected to the anode electrode is formed on a top surface of the insulation layer placed at an upper portion of the third anode diffusion layer.

4 more elements

Dependencies are inferred from the claim text.