Semiconductor device

Patent metadata

Field	Value
Publication number	US-2019096878-A1
Application number	US-201716094222-A
Country	US
Kind code	A1
Filing date	May 24, 2017
Priority date	Jun 14, 2016
Publication date	Mar 28, 2019
Grant date	—

Abstract

semiconductor device has a semiconductor substrate including an IGBT region operating as an IGBT provided by an emitter layer, a base layer, a drift layer and a collector layer, and a diode region operating as a diode and provided by an anode layer, the drift layer and a cathode layer. The semiconductor substrate further includes a guard ring of a second conduction type, provided in a surface layer of the drift layer in a peripheral region surrounding a device region where the IGBT region and the diode region are adjacent to each other. The cathode layer and the guard ring are positioned such as to satisfy L/d≥ 1.5, where L is a minimum value of a distance between the cathode layer and the guard ring as projected to a plane parallel to a surface of the semiconductor substrate, and d is a thickness of the semiconductor substrate.

First claim

1 . A semiconductor device, comprising a semiconductor substrate including:
a drift layer of a first conduction type; a base layer and an anode layer of a second conduction type provided in a surface layer on one side of the drift layer; an emitter layer selectively provided in the base layer; and a collector layer of a second conduction type and a cathode layer of a first conduction type provided in a surface layer on the other side of the drift layer, the emitter layer, the base layer, the drift layer, and the collector layer providing an IGBT region that operates as an IGBT, and the anode layer, the drift layer, and the cathode layer providing a diode region that operates as a diode adjacent to the IGBT region, wherein: the semiconductor substrate further includes a guard ring of a second conduction type, the guard ring being provided in a surface layer of the drift layer in a peripheral region surrounding a device region where the IGBT region and the diode region are adjacent to each other, and the guard ring being applied with voltage having a same potential as the anode layer; and the cathode layer and the guard ring are positioned such as to satisfy L/d≥1.5, where L is a minimum value of a distance between the cathode layer and the guard ring as projected to a plane parallel to a surface of the semiconductor substrate, and d is a thickness of the semiconductor substrate.

2 . The semiconductor device according to claim 1 , wherein
a damaged region is provided in the drift layer at least included in the diode region, the damaged region extends beyond the device region to reach the drift layer of the peripheral region, and the cathode layer and part of the guard ring not covered by the damaged region are positioned such as to satisfy L/d≥1.5, where L is a minimum value of a distance between the cathode layer and the part of the guard ring not covered by the damaged region as projected to the plane parallel to the surface of the semiconductor substrate, and d is the thickness of the semiconductor substrate.

3 . The semiconductor device according to claim 1 , wherein
the cathode layer and the guard ring are positioned such as to satisfy L/d≥1.8.

4 . The semiconductor device according to claim 1 , wherein
the cathode layer and the guard ring are positioned such as to satisfy L/d≥2.0.

5 . The semiconductor device according to claim 1 , wherein
the guard ring has a higher impurity concentration than the anode layer.

6 . The semiconductor device according to claim 1 , wherein
the device region includes a plurality of the IGBT regions and the diode regions alternately aligned in striped array, and the IGBT regions are positioned at both ends of the striped array of the device region.

Assignees

• Denso Corp

Inventors

• Arakawa Takafumi
• Takahashi Shigeki

Classifications

• H10D84/811

  Combinations of field-effect devices and one or more diodes, capacitors or resistors · CPC title

• H01L29/0623

  Electricity · mapped topic

• H01L29/1095

  Electricity · mapped topic

• H01L27/0664 Primary

  Electricity · mapped topic

• H01L29/7397

  Electricity · mapped topic