Semiconductor Device and Method of Manufacturing a Semiconductor Device
A method of manufacturing a semiconductor device includes forming a trench in a semiconductor body. The method further includes doping a part of the semiconductor body via sidewalls of the trench by plasma doping.
1 . A method of manufacturing a semiconductor device, comprising:
forming a trench in a semiconductor body; and
doping a part of the semiconductor body via sidewalls of the trench by plasma doping.
2 . The method of claim 1 , wherein the semiconductor device has a breakdown voltage of at least 100 V.
3 . The method of claim 1 , wherein doping the part of the semiconductor body by plasma doping comprises introducing dopants into the part of the semiconductor body via the sidewalls of the trench at a dose in a range of 5×10 11 cm −2 to 5×10 12 cm −2 .
4 . The method of claim 1 , wherein doping part of the semiconductor body by plasma doping comprises adjusting a DC-voltage pulse distance in a range of 100 μs to 10 ms.
5 . The method of claim 1 , wherein doping part of the semiconductor body by plasma doping comprises adjusting a DC-voltage pulse width in a range of 0.5 μs to 20 μs.
6 . The method of claim 1 , wherein doping the part of the semiconductor body by plasma doping comprises adjusting a DC-voltage pulse rise time smaller than 0.1 μs.
7 . The method of claim 1 , further comprising filling the trench with an insulating material.
8 . The method of claim 1 , further comprising filling the trench with a semiconductor material.
9 . The method of claim 1 , further comprising forming a first semiconductor layer on the doped part of the semiconductor body.
10 . The method of claim 9 , wherein the forming the first semiconductor layer on the doped part of the semiconductor body comprises forming a silicon layer by lateral epitaxy or low-temperature chemical vapor deposition.
11 . The method of claim 9 , wherein forming the first semiconductor layer on the doped part of the semiconductor body comprises:
forming an amorphous silicon layer on the doped part of the semiconductor body; and
crystallizing the amorphous silicon layer by a heat treatment.
12 . The method of claim 1 , further comprising forming an insulating outdiffusion barrier layer on the part of the semiconductor body.
13 . The method of claim 1 , wherein a superjunction device is formed as the semiconductor device including the doped part of the semiconductor body as a charge compensation layer.
14 . The method of claim 1 , wherein a transistor device is formed as the semiconductor device including the doped part of the semiconductor body as an edge termination structure.
15 . The method of claim 1 , wherein the semiconductor body includes a drift zone of a first conductivity type, and wherein doping the part of the semiconductor body by plasma doping comprises doping the part of the semiconductor body with dopants of a second conductivity type complementary to the first conductivity type.
16 . The method of claim 1 , wherein the semiconductor body includes a drift zone of a first conductivity type, and wherein doping the part of the semiconductor body by plasma doping comprises doping the part of the semiconductor body with dopants of the first conductivity type, the method further comprising:
forming a first semiconductor layer over the part of the semiconductor body in the trench; and
doping the first semiconductor layer by plasma doping with dopants of a second conductivity type complementary to the first conductivity type.
17 . The method of claim 16 , further comprising filling the trench with an insulating material.
18 . The method of claim 16 , further comprising filling the trench with a semiconductor material.
19 . The method of claim 16 , further comprising:
removing the first semiconductor layer from a bottom side of the trench;
forming a second semiconductor layer over the first semiconductor layer in the trench; and
doping the second semiconductor layer by plasma doping with dopants of the first conductivity type.
20 . A semiconductor device, comprising:
a first semiconductor region of a first conductivity type at a sidewall of a trench extending into a semiconductor body from a first side, wherein the semiconductor body further includes a drift zone of the first conductivity type;
a first semiconductor layer over the first semiconductor region in the trench, wherein the first semiconductor layer is of a second conductivity type complementary to the first conductivity type;
wherein the first conductivity type of the first semiconductor region is determined by a first species of dopants in the first semiconductor region; and
wherein a doping profile of the first species of dopants declines from a maximum in the first semiconductor region to a minimum or to a minimum doping plateau in the drift zone, a value of the doping at the maximum being at least a factor of ten higher than the doping at the minimum or at the minimum doping plateau.
21 . The semiconductor device of claim 20 , wherein the first semiconductor region lines the sidewall from a bottom side of the trench up to a top side of the trench at the first side.
22 . The semiconductor device of claim 20 , wherein a dose of the first species of dopants between a center of the trench to a center of the drift zone along a lateral direction parallel to the first side is in a range of 5×10 11 cm −2 to 5×10 12 cm −2 .
23 . The semiconductor device of claim 22 , wherein the second conductivity type of the first semiconductor layer is determined by a second species of dopants in the first semiconductor layer, and wherein a dose of the second species of dopants between a center of the trench to the center of the drift zone along a lateral direction parallel to the first side deviates by at least 10% from the corresponding dose of the first species of dopants.
24 . The semiconductor device of claim 20 , wherein the semiconductor device is a superjunction device and the first semiconductor layer is a charge compensation layer.