Semiconductor arrangement with a MOS-transistor and a parallel Schottky-diode

• US 6,998,678 B2
• Filed: 05/16/2002
• Issued: 02/14/2006
• Est. Priority Date: 05/17/2001
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Hirler, Franz, Werner, Wolfgang, Rieger, Walter, Krumrey, Joachim
• Primary Examiner(s): Owens, Douglas W.
• Application Number:
  US10/147,546
• Publication Number:
  US 20030020134A1
• Time in Patent Office: 1,370 Days
• Field of Search: 257/334, 257/471, 257/369, 257/368, 257/331, 257/155, 438/268, 438/237, 438/570, 438/571
• US Class Current: 257/334
• CPC Class Codes: H01L 27/0705 comprising components of the field effect type
• CPC Class Codes: H01L 29/0626 with a localised breakdown region, e.g. built-in avalanching region in self-protected thyristors H01L29/7424
• CPC Class Codes: H01L 29/1095 Body region, i.e. base region, of DMOS transistors or IGBTs cell layout H01L29/0696
• 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 29/42368 the thickness being non-uniform
• CPC Class Codes: H01L 29/7806 the other device being a Schottky barrier diode
• CPC Class Codes: H01L 29/7809 having both source and drain contacts on the same surface, i.e. Up-Drain VDMOS transistors
• CPC Class Codes: H01L 29/7811 with an edge termination structure guard regions per se H01L29/0619; field plates per se H01L29/402
• CPC Class Codes: H01L 29/7813 with trench gate electrode, e.g. UMOS transistors trench gate electrodes per se H01L29/4236

Abstract

The present invention relates to a semiconductor arrangement with a MOS transistor which has a gate electrode (40), arranged in a trench running in the vertical direction of a semiconductor body (100), and a Schottky diode which is connected in parallel with a drain-source path (D-S) and is formed by a Schottky contact between a source electrode and the semiconductor body.

Claims

1. A semiconductor configuration, comprising:

a semiconductor body including a first terminal zone of a first conductivity type, a second terminal zone of said first conductivity type, and a body zone of a second conductivity type formed between said first terminal zone and said second terminal zone, said semiconductor body defining a vertical direction, said first terminal zone, said body zone, and said second terminal zone configured one above another at least in sections in said vertical direction of said semiconductor body, said semiconductor body formed with a first trench extending in said vertical direction of said semiconductor body from said second terminal zone through said body zone right into said first terminal zone, said semiconductor body formed with a second trench extending in said vertical direction of said semiconductor body and said second trench defining sidewalls;

a control electrode formed in said first trench and insulated from said semiconductor body;

a terminal electrode insulated from said control electrode and contact-connecting said second terminal zone and said body zone, said terminal electrode disposed in sections in said second trench; and

a Schottky contact formed between said terminal electrode and said first terminal zone;

said Schottky contact directly contacting said body zone and formed in said second trench;

said body zone and said second terminal zone being uncovered at said sidewalls of said second trench and being contact-connected by said terminal electrode.

2. The semiconductor configuration according to claim 1, wherein:

said semiconductor body has a front side;

said first terminal zone extends in sections as far as said front side of said semiconductor body; and

said Schottky contact is formed at said front side of said semiconductor body.

3. The semiconductor configuration according to claim 1, wherein:

said semiconductor body is composed of silicon and includes a given region; and

in order to form said Schottky contact in said given region, said first terminal zone has a doping in said given region that is less than 1*10¹⁷.

4. The semiconductor configuration according to claim 1, wherein:

said semiconductor body is composed of silicon and includes a given region in which said Schottky contact is formed; and

said terminal electrode, in said given region of said Schottky contact, includes a material selected from a group consisting of aluminum, tungsten silicide, tantalum silicide, platinum suicide, cobalt suicide, and titanium suicide.

5. The semiconductor configuration according to claim 1, wherein:

said control electrode is a field plate formed in said first terminal zone;

said semiconductor body includes an insulation layer surrounding said field plate; and

said insulation layer is thicker near said first terminal zone than near said body zone and said second terminal zone.

6. The semiconductor configuration according to claim 1, wherein said semiconductor body includes first regions with a Schottky contact and second regions without a Schottky contact that are configured in a transition region between said first terminal electrode and said first terminal zone.

7. The semiconductor configuration according to claim 6, wherein said first regions and said second regions alternate with one another.

8. The semiconductor configuration according to claim 7, wherein said second regions are doped more highly than said first terminal zone.

9. The semiconductor configuration according to claim 7, wherein:

said first regions have a higher breakdown voltage than said second regions.

10. The semiconductor configuration according to claim 9, wherein said second regions are doped more highly than said first terminal zone.

11. The semiconductor configuration according to claim 6, wherein said second regions are doped more highly than said first terminal zone.

12. The semiconductor configuration according to claim 6, wherein:

said first regions have a higher breakdown voltage than said second regions.

13. The semiconductor configuration according to claim 6, wherein said second regions are of said second conductivity type.

14. The semiconductor configuration according to claim 13, wherein:

said second regions are doped more highly than said first terminal zone; and

said second regions also serve as a contact for said body zone.

15. The semiconductor configuration according to claim 6, wherein:

said second regions are doped more highly than said first terminal zone; and

said second regions also serve as a contact for said body zone.

16. The semiconductor component according to claim 6, wherein:

said semiconductor body has a front side;

said first terminal zone extends in sections as far as said front side of said semiconductor body; and

said first regions and said second regions are formed at said front side of said semiconductor body.

17. The semiconductor configuration according to claim 6, wherein:

said first regions and said second regions adjoin said second trench.

18. The semiconductor configuration according to claim 6, wherein:

said semiconductor body is formed with a plurality of trenches extending in said vertical direction of said semiconductor body;

said semiconductor body includes a plurality of mesa regions, each one of said plurality of said mesa regions formed between a respective pair of said plurality of said trenches;

said plurality of mesa regions are formed with a plurality of further trenches, a plurality of body zones, and a plurality of second terminal zones;

first ones of said plurality of said mesa regions each include a Schottky contact, and second ones of said plurality of said mesa regions each do not include a Schottky contact; and

said first ones of said plurality of said mesa regions are narrower than said second ones of said plurality of said mesa regions.

19. The semiconductor configuration according to claim 1, wherein:

said semiconductor body includes regions with a Schottky contact; and

in said regions, a Schottky barrier voltage is set by ion implantation.

20. The semiconductor configuration according to claim 1, comprising:

a second terminal electrode;

said semiconductor body including a side opposite said first terminal electrode; and

said second terminal electrode provided on said side of said semiconductor body opposite said first terminal electrode.

21. The semiconductor configuration according to claim 1, comprising:

a second electrode;

said semiconductor body including a side; and

said first terminal electrode and said second terminal electrode provided on said side of said semiconductor body.

22. A semiconductor configuration, comprising:

a semiconductor body containing a plurality of identically configured cells and defining a vertical direction, each of said cells containing;

a first terminal zone of a first conductivity type;

a second terminal zone of said first conductivity type;

a body zone of a second conductivity type formed between said first terminal zone and said second terminal zone;

said first terminal zone, said body zone, and said second terminal zone configured one above another at least in sections in said vertical direction of said semiconductor body;

said semiconductor body having a first trench formed therein extending in said vertical direction from said second terminal zone through said body zone right into said first terminal zone;

said semiconductor body having a second trench formed therein extending in said vertical direction of said semiconductor body;

a control electrode disposed in said first trench and insulated from said semiconductor body;

a terminal electrode insulated from said control electrode and contact connecting said second terminal zone and said body zone, said terminal electrode formed in said second trench; and

a Schottky contact formed by and between said terminal electrode and said first terminal zone, said Schottky contact directly contacting said body zone and formed in said second trench;

said body zone and said second terminal zone being contact-connected by said terminal electrode in said second trench.