Semiconductor switching element with integrated Schottky diode and process for producing the switching element and diode

• US 6,686,614 B2
• Filed: 05/30/2001
• Issued: 02/03/2004
• Est. Priority Date: 05/30/2000
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Tihanyi, Jenoe
• Primary Examiner(s): Flynn, Nathan J.
• Assistant Examiner(s): Mondt, Johannes P
• Application Number:
  US09/867,503
• Publication Number:
  US 20020000566A1
• Time in Patent Office: 979 Days
• Field of Search: 257/155, 257/156, 257/328-9, 257/335, 257/355
• US Class Current: 257/155
• CPC Class Codes: H01L 27/0629 in combination with diodes, or resistors, or capacitors
• CPC Class Codes: H01L 29/0653 adjoining the input or output region of a field-effect device, e.g. the source or drain region
• CPC Class Codes: H01L 29/0696 of cellular field-effect devices, e.g. multicellular DMOS transistors or IGBTs
• CPC Class Codes: H01L 29/41766 with at least part of the source or drain electrode having contact below the semiconductor surface, e.g. the source or drain electrode formed at least partially in a groove or with inclusions of conductor inside the semiconductor H01L29/41733 - H01L29/41758 take precedence
• CPC Class Codes: H01L 29/7806 the other device being a Schottky barrier diode
• CPC Class Codes: H01L 29/7839 with Schottky drain or source contact
• CPC Class Codes: H01L 29/872 Schottky diodes

Abstract

The invention relates to an integrated semiconductor switching element, that includes a semiconductor body having a first connection zone of a first conduction type and a second connection zone of the first conduction type. A body zone of a second conduction type is located in the semiconductor body. The body zone is located between the first connection zone and the second connection zone. A control electrode is located alongside the body zone and is insulated from the semiconductor body. A Schottky barrier is located on the second connection zone. A first connection electrode is electrically conductively connected to the first connection zone and to the Schottky barrier. The invention also relates to a process for producing a semiconductor switching element.

Claims

1. An integrated semiconductor switching element, comprising:

a semiconductor body having a first connection zone of a first conduction type, a second connection zone of the first conduction type, and a body zone of a second conduction type located between said first connection zone and said second connection zone, said body zone being formed in a well-like manner in said second connection zone, said first connection zone being formed in a well-like manner in said body zone, said semiconductor body being formed with a contact hole, said contact hole passing through said first connection zone and said body zone, said contact hole having a bottom and side walls;

a control electrode located alongside said body zone and insulated from said semiconductor body;

a Schottky barrier located on said second connection zone, said Schottky barrier being located in said contact hole and being formed on said bottom of said contact hole;

a first connection electrode electrically conductively connected to said first connection zone and to said Schottky barrier; and

an insulation layer located on said side walls of said contact hole.

2. The semiconductor switching element according to claim 1, wherein:

said semiconductor body has a front side;

said first connection electrode at least partially covers said side walls and said bottom of said contact hole; and

said first connection electrode at least partially covers said front side of said semiconductor body for electrically bonding said first connection zone.

3. The semiconductor switching element according to claim 1, wherein said Schottky barrier has platinum silicide.

4. A process for producing a semiconductor switching element which comprises:

providing a semiconductor body having a front side and having a first connection zone of a first conduction type and a second connection zone of the first conduction type, and configuring the first connection zone and the second connection zone one on top of the other;

providing the semiconductor body with a body zone of a second conduction type located between the first connection zone and the second connection zone;

producing at least one control electrode insulated from the semiconductor body and located alongside the body zone on the front side of the semiconductor body;

producing the control electrode causing the first connection zone being at least partially exposed and defining exposed regions of the first connection zone on the front side of the semiconductor body;

producing a contact hole with a bottom and side walls in the semiconductor body, the contact hole passing from the front side of the semiconductor body through the first connection zone and through the body zone and reaching into the second connection zone;

producing a Schottky barrier in the second connection zone in the contact hole;

applying an insulation layer on the side walls of the contact hole; and

producing a first connection electrode electrically bonding Schottky barrier and the exposed regions of the first connection zone.

5. The process according to claim 4, wherein the step of producing the control electrode includes:

applying an insulation layer to the front side of the semiconductor body;

applying an electrode layer to the insulation layer;

producing a second contact hole in the electrode layer and in the insulation layer such that the first connection zone is at least partially exposed on the front side of the semiconductor body; and

applying a further insulation layer to exposed regions of the control electrode.

6. The process according to claim 5, wherein the first contact hole has a smaller diameter than the second contact hole.

7. The process according to claim 4, which comprises:

producing the Schottky barrier by doping platinum silicide into the second connection zone.