Schottky diode

Patent metadata

Field	Value
Publication number	US-2016284872-A1
Application number	US-201615080338-A
Country	US
Kind code	A1
Filing date	Mar 24, 2016
Priority date	Mar 26, 2015
Publication date	Sep 29, 2016
Grant date	—

Abstract

Provided is a Schottky diode including a substrate, a drift layer on the substrate, the drift layer comprising an active region and a periphery positioned at an edge of the active region, a junction termination layer on a boundary between the active region and the periphery, a first metal layer configured to cover a part of the active region and a part of the junction termination layer, and a second metal layer configured to cover the first metal layer and the active region, wherein the first metal layer and the second metal layer contact the drift layer to provide a Schottky junction, and the first metal layer has a higher Schottky barrier height than the second metal layer.

First claim

What is claimed is:

1 . A Schottky diode comprising:
a substrate; a drift layer on the substrate, the drift layer comprising an active region and a periphery positioned at an edge of the active region; a junction termination layer on a boundary between the active region and the periphery; a first metal layer configured to cover a part of the active region and a part of the junction termination layer; and a second metal layer configured to cover the first metal layer and the active region, wherein the first metal layer and the second metal layer contact the drift layer to provide a Schottky junction, and the first metal layer has a higher Schottky barrier height than the second metal layer.

2 . The Schottky diode of claim 1 , wherein the substrate, the drift layer and the junction termination layer comprise silicon carbide SiC.

3 . The Schottky diode of claim 1 , further comprising:
a plurality of conductive layers spaced apart from each other on the active region, wherein the second metal layer covers the first metal layer, the active region, and the conductive layers.

4 . The Schottky diode of claim 3 , wherein the conductive layers have a conductive type different from that of the drift layer.

5 . The Schottky diode of claim 3 , wherein the conductive layers comprise a first part and a second part on the first part, and
the second part has a higher dopant concentration than the first part.

6 . The Schottky diode of claim 3 , further comprising:
a third metal layer configured to cover the conductive layers and a part of the active region, wherein the second metal layer covers the first metal layer, the active region, and the third metal layer.

7 . The Schottky diode of claim 6 , wherein the third metal layer comprises a same material as that of the first metal layer.

8 . The Schottky diode of claim 1 , wherein the junction termination layer has a conductive type different from that of the drift layer.

9 . The Schottky diode of claim 8 , wherein the junction termination layer comprises a first junction termination layer and a second junction termination layer on the first junction termination layer, and
the second junction termination layer has a higher dopant concentration than the first junction termination layer.

10 . A Schottky diode comprising:
a substrate; a drift layer on the substrate, the drift layer comprising an active region comprising trenches extending in a substrate direction and a periphery positioned at an edge of the active region; a junction termination layer on a boundary between the active region and the periphery; a first metal layer configured to cover a part of the active region and a part of the junction termination layer; and a plurality of second metal layers disposed separately from each other and configured to contact a top surface of the drift layer and the first metal layer, wherein the first metal layer and the second metal layer contact the drift layer to provide a Schottky junction, and the first metal layer has a higher Schottky barrier height than the second metal layer.

11 . The Schottky diode of claim 10 , wherein the first metal layer is coated along surface morphologies of the junction termination layer, the active region, and the second metal layer.

12 . The Schottky diode of claim 10 , further comprising:
conductive layers configured to contact a top surface of the drift layer and the first metal layer, wherein the conductive layers are disposed between the second metal layers.

13 . The Schottky diode of claim 10 , wherein side walls of the trenches has slopes of about 50 to about 90 degrees with respect to bottom surfaces of the trenches.

14 . The Schottky diode of claim 13 , wherein the conductive layers have a conductive type different from that of the drift layer.

15 . The Schottky diode of claim 14 , wherein the conductive layers comprise a first part and a second part on the first part, and
the second part has a higher dopant concentration than the first part.

Assignees

• Electronics & Telecommunications Res Inst

Inventors

• Park Kun Sik
• Won Jong Ii
• Cho Doo Hyung

Classifications

• H10D64/111

  Field plates · CPC title

• H10D64/23

  Electrodes carrying the current to be rectified, amplified, oscillated or switched, e.g. sources, drains, anodes or cathodes · CPC title

• H10D62/8325

  Silicon carbide · CPC title

• H10D62/106

  having supplementary regions doped oppositely to or in rectifying contact with regions of the semiconductor bodies, e.g. guard rings with PN or Schottky junctions · CPC title

• H10D8/051

  of Schottky diodes · CPC title