Semiconductor structure

• US 8,222,678 B2
• Filed: 08/17/2009
• Issued: 07/17/2012
• Est. Priority Date: 08/17/2009
• Status: Active Grant

• Current Assignee: Excelliance Mos Corporation
• Original Assignee: Excelliance Mos Corporation
• Inventors: Liu, Chu-Kuang
• Primary Examiner(s): Such, Matthew W
• Assistant Examiner(s): CARPENTER, ROBERT K
• Application Number:
  US12/542,687
• Publication Number:
  US 20110037113A1
• Time in Patent Office: 1,065 Days
• Field of Search: 257/213, 257/280, 257/284, 257/373
• US Class Current: 257/213
• 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 29/1095 Body region, i.e. base region, of DMOS transistors or IGBTs cell layout H01L29/0696
• CPC Class Codes: H01L 29/407 Recessed field plates, e.g. trench field plates, buried field plates
• 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 29/456 on silicon
• CPC Class Codes: H01L 29/47 Schottky barrier electrodes H01L29/435 takes precedence
• CPC Class Codes: H01L 29/66143 Schottky diodes
• CPC Class Codes: H01L 29/66727 with a step of recessing the source electrode
• CPC Class Codes: H01L 29/66734 with a step of recessing the gate electrode, e.g. to form a trench gate electrode
• CPC Class Codes: H01L 29/7813 with trench gate electrode, e.g. UMOS transistors trench gate electrodes per se H01L29/4236
• CPC Class Codes: H01L 29/782 the other device being a Schottky barrier diode
• CPC Class Codes: H01L 29/872 Schottky diodes

Abstract

A semiconductor structure including a substrate, at least one power MOSFET, a floating diode or a body diode, and at least one Schottky diode is provided. The substrate has a first area, a second area and a third area. The second area is between the first area and the third area. The at least one power MOSFET is in the first area. The floating diode or the body diode is in the second area. The at least one Schottky diode is in the third area. Further, the contact plugs of the power MOSFET and the Schottky diode include tungsten and are electronically connected to each other.

Claims

1. A semiconductor structure, comprising:

a substrate having a first area, a second area and a third area, wherein the second area is disposed between the first area and the third area;

at least one power metal-oxide-semiconductor field effect transistor (power MOSFET), disposed in the first area;

a floating diode or a body diode, disposed in the second area; and

at least one Schottky diode, disposed in the third area,

wherein a first contact plug of the power MOSFET is electrically connected to a second contact plug of the Schottky diode by a metal layer, and the first contact plug is disposed in the substrate in the first area, and

wherein the semiconductor device further comprises a trench gate disposed in the substrate, partially in the second area and partially in the third area, and the trench gate physically and electrically contacts the second contact plug.

2. The semiconductor structure as claimed in claim 1, wherein the first area surrounds the second area and the second area surrounds the third area.

3. The semiconductor structure as claimed in claim 1, wherein a cell pitch of the semiconductor structure is smaller than or equal to about 1.5 μ

m.

4. The semiconductor structure as claimed in claim 1, wherein a cell density of the semiconductor structure is greater than or equal to about 300 M cell/inch².

5. The semiconductor structure as claimed in claim 1, wherein the first and second contact plugs of the power MOSFET and the Schottky diode comprise tungsten.

6. The semiconductor structure as claimed in claim 1, wherein the Schottky diode is located at a bottom of the second contact plug, and the bottom of the second contact plug is higher than a bottom of the trench gate.

7. The semiconductor structure as claimed in claim 1, wherein a bottom of a trench gate of the power MOSFET is at a lower position than the Schottky diode.