Power semiconductor
View Patent ↗In order to produce a power semiconductor for operation at high blocking voltages, there is produced on a lightly doped layer having a doping of a first charge carrier type a medium-doped layer of the same charge carrier type. A highly doped layer is produced at that side of the medium-doped layer which is remote from the lightly doped layer, of which highly doped layer a part with high doping that remains in the finished semiconductor forms a second stop layer, wherein the doping of the highly doped layer is higher than the doping of the medium-doped layer. An electrode is subsequently indiffused into the highly doped layer. The part with low doping that remains in the finished semiconductor forms the drift layer and the remaining medium-doped part forms the first stop layer.
1. A method for producing a high-voltage power semiconductor for operation at high blocking voltages of greater than 2000 V comprising a drift layer having a doping of a first charge carrier type, a first stop layer having a doping of the first charge carrier type, and an electrode of a second charge carrier type, wherein the doping of the first stop layer is higher than the doping of the drift layer the method for producing the power semiconductor comprising:
proceeding from a lightly doped layer of a first charge carrier type, a medium-doped layer is produced at one side of the lightly doped layer to form the first stop layer, and the remaining part of the lightly doped layer forms the drift layer; and
indiffusing the electrode is into one of the drift layer and first stop layer, which has the highest doping of the layers of the first charge carrier type,
wherein after the production of the medium-doped layer and before the production of the electrode, at a side of the medium-doped layer which is remote from the lightly doped layer, producing a highly doped layer to form a second stop layer, wherein the doping of the highly doped layer is higher than the doping of the medium-doped layer, and metallizations are applied after the indiffusion of the electrode.
2. The method as claimed in claim 1 , wherein in order to form the first stop layer, particles of the first charge carrier type are implanted into the lightly doped layer and are driven in to a depth that is less than the depth of the lightly doped layer.
3. The method as claimed in claim 2 , wherein in order to form the second stop layer, the medium-doped layer together with a highly doped layer are connected to one another by bonding.
4. The method as claimed in claim 3 , wherein the highly doped layer is thinned in order to form the second stop layer.
5. The method as claimed in claim 1 , wherein in order to form the first stop layer on the lightly doped layer, a medium-doped layer is produced by epitaxial growth.
6. The method as claimed in claim 5 , wherein in order to form the second stop layer, particles of the first charge carrier type are implanted into the medium-doped layer and are driven in to a depth that is less than the depth of the medium-doped layer.
7. The method as claimed in claim 5 , wherein in order to form the second stop layer, the medium-doped layer together with a highly doped layer are connected to one another by bonding.
8. The method as claimed in claim 1 , wherein in order to form the second stop layer, particles of the first charge carrier type are implanted into the medium-doped layer and are driven in to a depth that is less than the depth of the medium-doped layer.
9. The method of claim 1 , wherein the drift layer is formed to a thickness of at least 150 μm.
10. The method of claim 1 , wherein the first stop layer is formed to a thickness of at least 10 μm.
11. The method of claim 1 , wherein the second stop is formed to a thickness of at least 1 μm.