Vertical MOSFET

• US 20060065925A1
• Filed: 09/26/2005
• Published: 03/30/2006
• Est. Priority Date: 09/29/2004
• Status: Abandoned Application

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: NEC Electronics Corporation (Renesas Electronics Corporation)
• Inventors: Yoshida, Shogo
• Application Number:
  US11/234,245
• Publication Number:
  US 20060065925A1
• Time in Patent Office: Days
• US Class Current: 257/329
• CPC Class Codes: H01L 2224/0603 Bonding areas having different sizes, e.g. different heights or widths
• 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 29/42376 characterised by the length or the sectional shape
• CPC Class Codes: H01L 29/7808 the other device being a breakdown diode, e.g. Zener diode
• 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

A vertical MOSFET includes a gate electrode formed inside a trench in a semiconductor layer, an interlayer insulating film formed above the semiconductor layer, a source electrode formed above the interlayer insulating film and electrically connected to a source region of the semiconductor layer through a conductive plug filled in a contact hole of the interlayer insulating film, and a protection diode having one end electrically connected to the source electrode and another end connected to the gate electrode through a gate metal line and including a plurality of PN junctions. The protection diode is formed inside a depressed portion in the semiconductor layer.

Claims

1. A vertical MOSFET comprising:

a gate electrode formed inside a trench in a semiconductor layer;

an interlayer insulating film formed above the semiconductor layer;

a source electrode formed above the interlayer insulating film and electrically connected to a source region of the semiconductor layer through a conductive plug filled in a contact hole of the interlayer insulating film; and

a protection diode having one end electrically connected to the source electrode and another end connected to the gate electrode through a gate metal line and including a plurality of PN junctions,

wherein the protection diode is formed inside a depressed portion in the semiconductor layer.

2. The vertical MOSFET according to claim 1, wherein the source electrode and the gate metal line are formed with a predetermined distance therebetween, and the source electrode and the gate metal line are formed across a part of a peripheral edge of the protection diode.

3. The vertical MOSFET according to claim 1, wherein the gate metal line and the gate electrode are electrically connected with each other through a gate polysilicon line formed in the depressed portion in the semiconductor layer.

4. The vertical MOSFET according to claim 2, wherein the gate metal line and the gate electrode are electrically connected with each other through a gate polysilicon line formed in the depressed portion in the semiconductor layer.

5. The vertical MOSFET according to claim 4, wherein the source electrode and the gate metal line are formed with a predetermined distance therebetween, and the source electrode and the gate metal line are formed across a part of a peripheral edge of the gate polysilicon line.