Reverse-conducting IGBT chip
Provided is a reverse-conducting IGBT chip including a first conductive type substrate; and several first conductive type short circuit regions arranged at intervals below the substrate and adjacent to a collector region. The short circuit regions are located outside a first preset range having the center of a chip as a center, in a second preset range outside the first preset range and having the center of the chip as a center, in a third preset range outside the second preset range and having the center of the chip as a center, and in a range outside the third preset range and enclosed by a chip edge.
1 . A reverse-conducting IGBT chip, comprising:
a first conductive type substrate;
a first conductive type drift layer above the substrate, wherein the drift layer comprises a cell region and a terminal region around the cell region;
a second conductive type collector region below the substrate; and
several first conductive type short circuit regions which are provided at an interval below the substrate and are adjacent to the collector region,
wherein the short circuit region is located outside a first preset range having a center of the chip as a center; in a second preset range outside the first preset range and having the center of the chip as a center, a ratio of a total area of the short circuit regions to an area of the collector region is a first preset threshold value; in a third preset range outside the second preset range and having the center of the chip as a center, a ratio of a total area of the short circuit regions to an area of the collector region is a second preset threshold value; in a range outside the third preset range and enclosed by a chip edge, a ratio of a total area of the short circuit regions to an area of the collector region is a third preset threshold value; and the first preset threshold value is less than the second preset threshold value, and the second preset threshold value is less than the third preset threshold value;
wherein a size of the first preset range is selected to be able to eliminate a primary voltage snap-back phenomenon of the chip;
wherein a size of the second preset range and a size of the third preset range, as well as the first preset threshold value, the second preset threshold value, and the third preset threshold value are selected to able to eliminate a secondary voltage snap-back phenomenon of the chip;
wherein the first preset threshold value is in a range from 0.1 to 0.3;
wherein the second preset threshold value is calculated by the following calculation formula:
s=K×r
where s is the second preset threshold value, K is a constant number, which is in a range from 1.1 to 2.0, and r is the first preset threshold; and
wherein the third preset threshold value is calculated by the following calculation formula:
t=K 2 ×r
where t is the third preset threshold value.
2 . The reverse-conducting IGBT chip according to claim 1 , wherein
the chip is a chip of a square; and
each of the first preset range, the second preset range, and the third preset range has a shape of a square.
3 . The reverse-conducting IGBT chip according to claim 2 , wherein
a side length of the first preset range is calculated by the following calculation formula:
a= 2 W= 2× C ×√{square root over ( L×Q/ND )},
wherein a is the side length of the first preset range; W is a half of the side length of the first preset range; C is a constant number, and is in a range from √{square root over (3)} to 2√{square root over (2)}; L is a thickness of the chip; Q is an ion implantation dosage of the substrate; and ND is an ion doping concentration of the drift layer;
a side length of the second preset range is calculated by the following calculation formula:
b
=
2
(
W
+
X
-
W
3
)
,
wherein b is the side length of the second preset range, and X is a half of a side length of the chip; and
a side length of the third preset range is calculated by the following calculation formula:
c
=
2
(
W
+
X
-
W
3
×
2
)
,
wherein c is the side length of the third preset range.
4 . The reverse-conducting IGBT chip according to claim 2 , wherein
a side length of the first preset range is calculated by the following calculation formula:
a= 2 W= 2× C ×√{square root over ( L×Q/ND )},
wherein a is the side length of the first preset range; W is a half of the side length of the first preset range; C is a constant number, and is in a range from √{square root over (3)} to 2√{square root over (2)}; L is a thickness of the chip; Q is an ion implantation dosage of the substrate; and ND is an ion doping concentration of the drift layer;
a side length of the second preset range is calculated by the following calculation formula:
b
=
2
(
W
+
X
-
W
2
)
,
wherein b is the side length of the second preset range, and X is a half of a side length of the chip; and
a side length of the third preset range is calculated by the following calculation formula:
c
=
2
(
W
+
X
-
W
2
+
X
-
W
3
)
,
wherein c is the side length of the third preset range.
5 . The reverse-conducting IGBT chip according to claim 1 , wherein
the chip is a chip of a square; and
each of the first preset range, the second preset range, and the third preset range is circular.
6 . The reverse-conducting IGBT chip according to claim 5 , wherein
a radius of the first preset range is calculated by the following calculation formula:
W=C ×√{square root over ( L×Q/ND )},
wherein W is the radius of the first preset range; C is a constant number, and is in a range from √{square root over (3)} to 2√{square root over (2)}; L is a thickness of the chip; Q is an ion implantation dosage of the substrate; and ND is an ion doping concentration of the drift layer;
a radius of the second preset range is calculated by the following calculation formula:
b
=
W
+
X
-
W
3
,
wherein b is the radius of the second preset range, and X is a half of a side length of the chip; and
a radius of the third preset range is calculated by the following calculation formula:
c
=
W
+
X
-
W
3
×
2
,
wherein c is the radius of the third preset range.
7 . The reverse-conducting IGBT chip according to claim 5 , wherein
a radius of the first preset range is calculated by the following calculation formula:
W=C ×√{square root over ( L×Q/ND )},
wherein W is the radius of the first preset range; C is a constant number, and is in a range from √{square root over (3)} to 2√{square root over (2)}; L is a thickness of the chip; Q is an ion implantation dosage of the substrate; and ND is an ion doping concentration of the drift layer;
a radius of the second preset range is calculated by the following calculation formula:
b
=
W
+
X
-
W
2
,
wherein b is the radius of the second preset range, and X is a half of a side length of the chip; and
a radius of the third preset range is calculated by the following calculation formula:
c
=
W
+
X
-
W
2
+
X
-
W
3
,
wherein c is the radius of the third preset range.