Power Semiconductor Device

Patent metadata

Field	Value
Publication number	US-2019355841-A1
Application number	US-201916413815-A
Country	US
Kind code	A1
Filing date	May 16, 2019
Priority date	May 17, 2018
Publication date	Nov 21, 2019
Grant date	—

Abstract

A power semiconductor device includes a semiconductor body having a front side coupled to a first load terminal structure and a backside coupled to a second load terminal structure. A front side structure arranged at the front side is at least partially included in the semiconductor body and defines a front side active region configured to conduct a load current between the load terminal structures. The front side structure includes first and second lateral edge portions and a first corner portion that forms a transition between the lateral edge portions. A drift region included in the semiconductor body is configured to carry the load current. A backside emitter region arranged in the semiconductor body in contact with the second load terminal has a net dopant concentration higher than a net dopant concentration of the drift region.

First claim

1 . A power semiconductor device, comprising:
a semiconductor body having a front side coupled to a first load terminal structure and a backside coupled to a second load terminal structure; a front side structure being arranged at the front side and at least partially included in the semiconductor body, the front side structure defining a front side active region configured to conduct a load current between the first load terminal structure and the second load terminal structure in a conducting state of the power semiconductor device, the front side structure comprising a first lateral edge portion, a second lateral edge portion, and a first corner portion forming a transition between the first lateral edge portion and the second lateral edge portion; a drift region of a first conductivity type included in the semiconductor body and configured to carry the load current; and a backside emitter region arranged in the semiconductor body in contact with the second load terminal, the backside emitter region having a net dopant concentration that is higher than a net dopant concentration of the drift region, wherein, in a vertical projection, the backside emitter region laterally terminates at a first distance from the first lateral edge portion and/or the second lateral edge portion and at a second distance from the first corner portion, the second distance being larger than the first distance.

2 . The power semiconductor device of claim 1 , wherein the first distance and the second distance are both positive, and wherein the second distance is at least 1.5 times the first distance.

3 . The power semiconductor device of claim 1 , wherein a difference in distance between the second distance and the first distance is at least a diffusion length of free charge carriers.

4 . The power semiconductor device of claim 1 , wherein a difference in distance between the second distance and the first distance is at least half a vertical extension of the drift region.

5 . The power semiconductor device of claim 1 , wherein the first distance is at least 0.5 times a diffusion length of free charge carriers.

6 . The power semiconductor device of claim 1 , wherein the first lateral edge portion and the second lateral edge portion are straight edge portions.

7 . The power semiconductor device of claim 1 , wherein the first lateral edge portion and the second lateral edge portion are in parallel to corresponding lateral chip edges of the semiconductor body.

8 . The power semiconductor device of claim 1 , wherein the first corner portion is a rounded corner.

9 . The power semiconductor device of claim 1 , wherein the power semiconductor device is or comprises a diode.

10 . The power semiconductor device of claim 9 , wherein the front side structure is an anode region of a second conductivity type complementary to the first conductivity type, the anode region being included in the semiconductor body.

11 . The power semiconductor device of claim 9 , wherein the backside emitter region is a cathode region of the first conductivity type.

12 . The power semiconductor device of claim 1 , wherein the power semiconductor device is or comprises an IGBT.

13 . The power semiconductor device of claim 12 , wherein the front side structure is a cell field comprising a plurality of IGBT cells.

14 . The power semiconductor device of claim 13 , wherein the cell field comprises a plurality of trenches, which are in each case separated from a respective neighboring trench of the cell field by a semiconductor mesa region, and wherein a lateral extension of the semiconductor mesa regions in a vicinity of an outer edge of the cell field is larger than a lateral extension of semiconductor mesa regions in a central portion of the cell field.

15 . The power semiconductor device of claim 13 , wherein the cell field comprises a plurality of trenches, which are in each case separated from a respective neighboring trench of the cell field by a semiconductor mesa region, and wherein a lateral extension of the semiconductor mesa regions in a vicinity of the first corner portion is larger than a lateral extension of semiconductor mesa regions in a vicinity of the first and/or second lateral edge portion.

16 . The power semiconductor device of claim 12 , wherein the backside emitter region is of a second conductivity type that is complementary to the first conductivity type.

17 . The power semiconductor device of claim 16 , further comprising a second backside region of the second conductivity type, the second backside region being arranged in contact with the second load terminal and having a net dopant concentration of the second conductivity type that is lower than the net dopant concentration of the second conductivity type of the backside emitter region.

18 . A power semiconductor device, comprising:
a semiconductor body having a front side coupled to a first load terminal structure and a backside coupled to a second load terminal structure; a front side structure arranged at the front side and at least partially included in the semiconductor body, the front side structure comprising a cell field having a plurality of IGBT cells which define a front side active region that is configured to conduct a load current between the first load terminal structure and the second load terminal structure in a conducting state of the power semiconductor device, the front side structure having: a recess defining a pad region for providing a contact pad at the front side; a third lateral edge portion extending alongside the pad region; a fourth lateral edge portion extending alongside the pad region; and a second corner portion that forms a transition between the third lateral edge portion and the fourth lateral edge portion; a drift region of a first conductivity type included in the semiconductor body and configured to carry the load current; and a backside emitter region arranged in the semiconductor body in contact with the second load terminal, the backside emitter region having a net dopant concentration that is higher than a net dopant concentration of the drift region, wherein, in a vertical projection, an overlap of the pad region and the backside emitter region laterally terminates at a third distance from the third lateral edge portion and/or the fourth lateral edge portion and at a fourth distance from the second corner portion, the fourth distance being larger than the third distance.

19 . The power semiconductor device of claim 18 , wherein the third lateral edge portion and the fourth lateral edge portion are in parallel to corresponding lateral edges of a gate pad arranged inside the pad region at the front side of the semiconductor body.

Assignees

• Infineon Technologies Ag

Inventors

• Stoib Benedikt
• Schulze Hans-Joachim
• Seifert Max Christian

Classifications

• H01L29/1095

  Electricity · mapped topic

• H01L29/7397 Primary

  Electricity · mapped topic

• H01L29/0804

  Electricity · mapped topic

• H10D62/129

  Cathode regions of diodes · CPC title

• H10D62/393

  Body regions of DMOS transistors or IGBTs  (cell layout of DMOS H10D62/127) · CPC title