Semiconductor device

Patent metadata

Field	Value
Publication number	US-11876131-B2
Application number	US-201916366379-A
Country	US
Kind code	B2
Filing date	Mar 27, 2019
Priority date	May 29, 2018
Publication date	Jan 16, 2024
Grant date	Jan 16, 2024

Abstract

A source pad of a main semiconductor element is electrically connected to an n + -type source region via a barrier metal. A temperature sensing part is a poly-silicon diode formed by a pn junction between a p-type poly-silicon layer that is a p-type anode region and an n-type poly-silicon layer that is an n-type cathode region. The temperature sensing part is provided, via the field insulating film, on a front surface of a same semiconductor substrate as the main semiconductor element. An anode pad and a cathode pad are in direct contact with the p-type poly-silicon layer and the n-type poly-silicon layer, respectively. The source pad, the anode pad, and the cathode pad are aluminum alloy films.

First claim

What is claimed is:

1. A semiconductor device, comprising:
a semiconductor substrate of a first conductivity type including a semiconductor material having a bandgap that is wider than that of silicon;
a second-conductivity-type region of a second conductivity type provided in a surface layer of a first main surface of the semiconductor substrate;
a barrier metal disposed on the second-conductivity-type region;
an insulated-gate field effect transistor with a trench gate structure, including a base region and a source pad, the base region comprising the second-conductivity-type region, the source pad being electrically connected to the second-conductivity-type region via the barrier metal;
an insulating layer disposed on the semiconductor substrate;
a second-conductivity-type poly-silicon layer of the second conductivity type provided on the first main surface of the semiconductor substrate, via the insulating layer;
a first-conductivity-type poly-silicon layer of the first conductivity type provided on the first main surface of the semiconductor substrate next to the second-conductivity-type poly-silicon layer, via the insulating layer, a side face of the first-conductivity-type poly-silicon layer being in contact with a side face of the second-conductivity-type poly-silicon layer; and
a diode formed by a pn junction between the second-conductivity-type poly-silicon layer and the first-conductivity-type poly-silicon layer, the diode including an anode pad and a cathode pad, the anode pad being electrically connected to and in direct contact with the second-conductivity-type poly-silicon layer, the cathode pad being electrically connected to the first-conductivity-type poly-silicon layer, wherein
the source pad is a metal film containing aluminum as a main constituent,
the anode pad is a metal film containing aluminum as a main constituent, the metal film of the anode pad being made of a single layer, being in direct contact with the second-conductivity-type poly-silicon layer and being free of any barrier metal,
the cathode pad is a metal film containing aluminum as a main constituent, the metal film of the cathode pad being made of a single layer, being in direct contact with the first-conductivity-type poly-silicon layer and being free of any barrier metal, and
the source pad is apart from the anode pad and the cathode pad in a plan view of the semiconductor device.

2. The semiconductor device according to claim 1 , wherein the barrier metal is any one of a titanium film, a titanium nitride film, and a stacked film of the titanium film and the titanium nitride.

3. The semiconductor device according to claim 1 , wherein
the cathode pad is grounded, and
the diode detects a temperature of the insulated-gate field effect transistor using temperature characteristics of the insulated-gate field effect transistor.

4. A semiconductor device, comprising:
a semiconductor substrate of a first conductivity type including a semiconductor material having a bandgap that is wider than that of silicon;
a second-conductivity-type region of a second conductivity type provided in a surface layer of a first main surface of the semiconductor substrate;
a barrier metal disposed on the second-conductivity-type region;
an insulated-gate field effect transistor with a trench gate structure, including a base region and a source pad, the base region comprising the second-conductivity-type region, the source pad being electrically connected to the second-conductivity-type region via the barrier metal;
an insulating layer disposed on the semiconductor substrate; and
one or more circuit parts for protecting or controlling the insulated-gate field effect transistor, the one or more circuit parts being provided on the semiconductor substrate and including:
a poly-silicon layer provided on the first main surface of the semiconductor substrate via the insulating layer, and
an electrode pad electrically connected to and in direct contact with the poly-silicon layer, wherein

the source pad is a metal film containing aluminum as a main constituent,
the electrode pad is a metal film containing aluminum as a main constituent, the metal film of the electrode pad being made of a single layer, being in direct contact with the poly-silicon layer and being free of any barrier metal, and
the source pad is apart from the electrode pad in a plan view of the semiconductor device.

5. A semiconductor device, comprising:
a semiconductor substrate of a first conductivity type including a semiconductor material having a bandgap that is wider than that of silicon;
a second-conductivity-type region of a second conductivity type provided in a surface layer of a first main surface of the semiconductor substrate;
a barrier metal disposed on the second-conductivity-type region;
an insulated-gate field effect transistor with a trench gate structure having a gate electrode, including a base region, a source pad and a gate pad, the base region comprising the second-conductivity-type region, the source pad being electrically connected to the second-conductivity-type region via the barrier metal, the gate pad being electrically connected to the gate electrode;
an insulating layer disposed on the semiconductor substrate;
a second-conductivity-type poly-silicon layer of the second conductivity type provided on the first main surface of the semiconductor substrate, via the insulating layer;
a first-conductivity-type poly-silicon layer of the first conductivity type provided on the first main surface of the semiconductor substrate next to the second-conductivity-type poly-silicon layer, via the insulating layer, a side face of the first-conductivity-type poly-silicon layer being in contact with a side face of the second-conductivity-type poly-silicon layer; and
a diode formed by a pn junction between the second-conductivity-type poly-silicon layer and the first-conductivity-type poly-silicon layer, the diode including an anode pad and a cathode pad, the anode pad being electrically connected to and in direct contact with the second-conductivity-type poly-silicon layer, the cathode pad being electrically connected to the first-conductivity-type poly-silicon layer, wherein
the source pad is a metal film containing aluminum as a main constituent,
the anode pad is a metal film containing aluminum as a main constituent, the metal film of the anode pad being made of a single layer, being in direct contact with the second-conductivity-type poly-silicon layer and being free of any barrier metal, and
the gate pad is apart from the anode pad and the cathode pad in a plan view of the semiconductor device.

6. The semiconductor device according to claim 5 , wherein the source pad is in direct contact with the first-conductivity-type poly-silicon layer and configures the cathode pad.

7. The semiconductor device according to claim 5 , wherein the source pad is connected to the first-conductivity-type poly-silicon layer via the barrier metal and configures the cathode pad.

8. The semiconductor device according to claim 7 , wherein
the cathode pad and the first-conductivity-type poly-silicon layer are electrically connected to each other at a contact area, the contact area including a first area and a second area,
the barrier metal is disposed between the cathode pad and the first-conductivity-type poly-silicon layer within the first area, so that the cathode pad and the first-conductivity-type poly-silicon layer are connected to each other at the first area via the barrier metal, and
the cathode pad and the first-conductivity-type poly-silicon layer are in direct contact with each other at the second area.

Assignees

• Fuji Electric Co Ltd

Inventors

• Hashizume Yuichi
• Kumada Keishirou
• Suzuki Yoshihisa
• Hoshi Yasuyuki

Classifications

• H10D64/62

  Electrodes ohmically coupled to a semiconductor · CPC title

• H10D62/8325

  Silicon carbide · CPC title

• H10D48/387

  Devices controllable only by the variation of applied heat · CPC title

• H10D30/668 Primary

  having trench gate electrodes, e.g. UMOS transistors · CPC title

• H10D8/00

  Diodes (variable-capacitance diodes H10D1/64; gated diodes H10D12/00) · CPC title