Soft switching semiconductor device and method for producing thereof

Patent metadata

Field	Value
Publication number	US-9324783-B2
Application number	US-201414501298-A
Country	US
Kind code	B2
Filing date	Sep 30, 2014
Priority date	Sep 30, 2014
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

A semiconductor device has a semiconductor body with a first side and a second side that is arranged distant from the first side in a first vertical direction. The semiconductor device has a rectifying junction, a field stop zone of a first conduction type, and a drift zone of a first conduction type arranged between the rectifying junction and the field stop zone. The semiconductor body has a net doping concentration along a line parallel to the first vertical direction. At least one of (a) and (b) applies:
(a) the drift zone has, at a first depth, a charge centroid, wherein a distance between the rectifying junction and the charge centroid is less than 37% of the thickness the drift zone has in the first vertical direction; (b) the absolute value of the net doping concentration comprises, along the straight line and inside the drift zone, a local maximum value.

First claim

The invention claimed is:

1. A semiconductor device comprising:
a semiconductor body having a first side and a second side opposite the first side, the second side being arranged distant from the first side in a first vertical direction;
a rectifying junction;
a field stop zone of a first conduction type arranged in the semiconductor body; and
a drift zone of the first conduction type arranged in the semiconductor body between the rectifying junction and the field stop zone;
wherein the semiconductor body has, along a straight line running parallel to the first vertical direction, a net doping concentration; and
wherein at least one of (a) and (b) applies:
(a) the drift zone comprises, at a first depth, a doping charge centroid, wherein a distance between the rectifying junction and the doping charge centroid is less than 37% of a thickness of the drift zone in the first vertical direction;
(b) the absolute value of the net doping concentration comprises, along the straight line and inside the drift zone, a local maximum value.

2. The semiconductor device of claim 1 , wherein the local maximum value is located at a depth that is;
greater than a depth of the rectifying junction; and
less than the mean value of the depth of the rectifying junction and a depth of a border between the drift zone and the field stop zone.

3. The semiconductor device of claim 1 , wherein the drift zone comprises a second depth arranged distant from both the rectifying junction and the field stop zone, at which second depth the decimal logarithm of the product of the net doping concentration and 1 cm 3 comprises, in the first vertical direction, a gradient

ⅆ

ⅆ
v

⁢

⁢
1

⁢

log
10

⁡

(

N
NET

·

cm
3

)

of less than—0.01/μm, wherein
v 1 is the first vertical direction; and
N NET is the net doping concentration.

4. The semiconductor device of claim 1 , wherein the drift zone comprises a second depth arranged distant from both the rectifying junction and the field stop zone, at which second depth the decimal logarithm of the product of the net doping concentration and 1 cm 3 comprises, in the first vertical direction, a gradient

ⅆ

ⅆ
v

⁢

⁢
1

⁢

log
10

⁡

(

N
NET

·

cm
3

)

of less than—0.02/μm, wherein
v 1 is the first vertical direction; and
N NET is the net doping concentration.

5. The semiconductor device of claim 1 , wherein:
the decimal logarithm of the product of the net doping concentration and 1 cm 3 comprises, inside the drift zone, for each second depth within a depth range, in the first vertical direction a gradient

ⅆ

ⅆ
v

⁢

⁢
1

⁢

log
10

⁡

(

N
NET

·

cm
3

)

less than—0.01/μm;
each second depth is greater than a depth of the rectifying junction and less than a depth of a border between the drift zone and the field stop zone; and
the depth range is at least 10% of a thickness of the drift zone, wherein
v 1 is the first vertical direction; and
N NET is the net doping concentration.

6. The semiconductor device of claim 5 , wherein:
the decimal logarithm of the product of the net doping concentration and 1 cm 3 comprises, inside the drift zone, for each second depth within a depth range, in the first vertical direction a gradient

ⅆ

ⅆ
v

⁢

⁢
1

⁢

log
10

⁡

(

N
NET

·

cm
3

)

of less than—0.02/μm.

7. The semiconductor device of claim 1 , wherein the drift zone comprises, in the first vertical direction, a local maximum of the net doping concentration arranged distant from both the rectifying junction and the field stop zone.

8. The semiconductor device of claim 1 , comprising a minority charge carrier delivering structure having a second conduction type complementary to the first conduction type, the minority charge carrier delivering structure being embedded in the field stop zone such that the field stop zone continuously extends between the drift zone and the first side.

9. The semiconductor device of claim 8 , wherein the minority charge carrier delivering structure is reticulated.

10. The semiconductor device of claim 8 , wherein the minority charge carrier delivering structure comprises a plurality of islands arranged distant from one another.

11. The semiconductor device of claim 8 , wherein the minority charge carrier delivering structure is arranged distant from the second side.

12. The semiconductor device of claim 8 , wherein the mino

Assignees

• Infineon Technologies Ag

Inventors

• Falck Elmar
• Schmidt Gerhard

Classifications

• H10W10/051

  of isolation region based on field-effect · CPC title

• H10W10/50

  Isolation regions based on field-effect · CPC title

• H10W10/031 Primary

  of isolation regions comprising PN junctions · CPC title

• H10W10/30

  Isolation regions comprising PN junctions · CPC title

• H10D62/129

  Cathode regions of diodes · CPC title