Semiconductor device having switching element and free wheel diode and method for controlling the same

Patent metadata

Field	Value
Publication number	US-9515067-B2
Application number	US-201414513685-A
Country	US
Kind code	B2
Filing date	Oct 14, 2014
Priority date	Jul 27, 2010
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

A semiconductor device includes a switching element having: a drift layer; a base region; an element-side first impurity region in the base region; an element-side gate electrode sandwiched between the first impurity region and the drift layer; a second impurity region contacting the drift layer; an element-side first electrode coupled with the element-side first impurity region and the base region; and an element-side second electrode coupled with the second impurity region, and a FWD having: a first conductive layer; a second conductive layer; a diode-side first electrode coupled to the second conductive layer; a diode-side second electrode coupled to the first conductive layer; a diode-side first impurity region in the second conductive layer; and a diode-side gate electrode in the second conductive layer sandwiched between first impurity region and the first conductive layer and having a first gate electrode as an excess carrier injection suppression gate.

First claim

What is claimed is:

1. A semiconductor device comprising:
a semiconductor switching element with an insulated gate structure; and
a free wheel diode,
wherein the semiconductor switching element includes:
a drift layer having a first conductivity type;
a base region having a second conductivity type and arranged on the drift layer;
an element-side first impurity region having the first conductivity type, arranged in a surface part of the base region, separated from the drift layer by the base region therebetween, and having an impurity concentration higher than the drift layer;
an element-side gate electrode disposed in the base region sandwiched between the first impurity region and the drift layer through a gate insulating film;
a second impurity region having the first or second conductivity type, contacting the drift layer, having an impurity concentration higher than the drift layer, and separated from the base region;
an element-side first electrode electrically coupled with the element-side first impurity region and the base region; and
an element-side second electrode electrically coupled with the second impurity region,

wherein the semiconductor switching element provides an inversion channel in a portion of the base region opposite to the element-side gate electrode via the gate insulating film therebetween,
wherein the semiconductor switching element provides a current flowing between the element-side first electrode and the element-side second electrode through the channel,
wherein the free wheel diode includes:
a first conductivity type layer;
a second conductivity type layer arranged on the first conductivity type layer;
a diode-side first electrode coupled to the second conductivity type layer; and
a diode-side second electrode coupled to the first conductivity type layer,

wherein the free wheel diode provides a p-n junction including the first conductivity type layer and the second conductivity type layer,
wherein the free wheel diode provides a current flowing between the diode-side first electrode and the diode-side second electrode,
wherein the semiconductor switching element and the free wheel diode are coupled in parallel with each other,
wherein the free wheel diode further includes:
a diode-side first impurity region having the first conductivity type, arranged in a surface part of the second conductivity type layer, and having an impurity concentration higher than the first conductivity type layer; and
a diode-side gate electrode arranged in the second conductivity type layer sandwiched between the first impurity region and the first conductivity type layer through a gate insulating film,

wherein the diode-side gate electrode includes a first gate electrode,
wherein the first gate electrode provides an excess carrier injection suppression gate,
wherein, when a gate voltage is applied to the diode-side gate electrode, the first gate electrode provides another inversion channel in a part of the second conductivity type layer,
wherein the part of the second conductivity type layer is arranged between the diode-side first impurity region and a predetermined position, which is disposed between the diode-side first impurity region and the first conductivity type layer,
wherein the semiconductor switching element and the free wheel diode are arranged in one chip,
wherein the drift layer is the first conductivity type layer,
wherein the base region is the second conductivity type layer,
wherein the element-side first electrode is the diode-side first electrode,
wherein the element-side second electrode is the diode-side second electrode,
wherein the element-side first impurity region is the diode-side first impurity region,
wherein the element-side gate electrode is the diode-side gate electrode,
wherein the first gate electrode is arranged between the element-side first impurity region via the gate insulating film and a predetermined position of the base region,
wherein the element-side gate electrode includes a second gate electrode,
wherein the second gate electrode is arranged between the predetermined position of the base region via the gate insulating film and the drift layer,
wherein, when the gate voltage is applied to the element-side gate electrode, the first gate electrode and the second gate electrode function as a semiconductor switching element driving gate,
wherein the semiconductor switching element driving gate provides the channel connecting between the element-side first impurity region and the drift layer together in the base region, and
the predetermined position of the base region is provided by a deepest position of the first gate electrode, the deepest position being farthest from the diode-side first electrode among any position of the first gate electrode.

2. The semiconductor device of claim 1 , further comprising:
a trench penetrating the element-side first impurity region and the base region and reaching the drift layer,
wherein the first gate electrode and the second gate electrode are arranged in the trench with an insulating film therebetween so that a double gate-type trench gate structure is provided, and
wherein the semiconductor switching element has a trench gate structure.

3. The semiconductor device of claim 2 ,
wherein the second impurity region is a semiconductor substrate having the first conductivity type,
wherein the drift layer is arranged on the semiconductor substrate,
wherein the semiconductor switching element provides the channel in a portion of the base region located on a side of the trench, and
wherein the semiconductor switching element is a vertical MOSFET for flowing a current in a direction perpendicular to the semiconductor substrate.

4. The semiconductor device of claim 2 ,
wherein the second impurity region is a semiconductor substrate further including a second conductivity type portion,
wherein the drift layer is arranged on the semiconductor substrate,
wherein the semiconductor switching element provides the channel in a portion of the base region located on a side of the trench, and
wherein the semiconductor switching element is a vertical IGBT for flowing a current in a direction perpendicular to the semiconductor substrate.

5. The semiconductor device of claim 2 , wherein the base region is arranged in a surface part of the drift layer,
wherein the element-side first impurity region is arranged in a surface part of the base region,
wherein the second impurity region has the first conductivity type,
wherein the second impurity region is arranged in another surface part of the drift layer and separated from the base region,
wherein the trench extends in a direction parallel to a surface of the drift layer,
wherein the trench penetrates the first impurity region and the base region and reaches the drift layer,
wherein the semiconductor switching element provides the channel in a portion of the base region located on a side of the trench, and
wherein the semiconductor switching element is a horizontal MOSFET for flowing a current in a horizontal direction parallel to the surface of the drift layer.

6. The semiconductor device of claim 2 ,
wherein the base region is arranged in a surface part of the drift layer,
wherein the element-side first impurity region is arranged in a surface part of the base region,
wherein the second impurity region further includes a second conductivity type portion,
wherein the second impurity region is arranged in another surface part of the drift layer and separated from the base region,
wherein the trench extends in a direction parallel to a surface of the drift layer,
wherein the trench penetrates the first impurity region and the base region and reaches the drift layer,
wherein the semicond

Assignees

• Denso Corp

Inventors

• Saikaku Hirotaka
• Yamamoto Tsuyoshi
• Mizuno Shoji
• Sumitomo Masakiyo
• Fujii Tetsuo
• Sakakibara Jun
• Yamaguchi Hitoshi
• Hattori Yoshiyuki
• Taguchi Rie
• Kuwahara Makoto

Classifications

• H10D64/519

  characterised by their top-view geometrical layouts · CPC title

• H10D62/127

  of cellular field-effect devices, e.g. multicellular DMOS transistors or IGBTs · CPC title

• H10D62/111

  Multiple RESURF structures, e.g. double RESURF or 3D-RESURF structures · CPC title

• H10D12/211

  Gated diodes · CPC title

• H10D8/00

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