Method for forming a multilayer structure
The method for forming a multilayer structure on a substrate comprises providing a stack successively comprising an electron hole blocking layer, a first layer made from N-doped semiconductor material having a dopant concentration greater than or equal to 10 18 atoms/cm 3 or P-doped semiconductor material, and a second layer made from semiconductor material of different nature. A lateral electric contact pad is made between the first layer and the substrate, and the material of the first layer is subjected to anodic treatment in an electrolyte.
1. A method for forming a multilayer structure on a substrate, comprising the following steps:
providing a stack successively comprising a hole blocking layer, reactive to anodic treatment made from N-doped semiconductor material having a dopant concentration greater than or equal to 10 18 atoms/cm 3 or P-doped semiconductor material, and a second layer made from semiconductor resistant to anodic treatment,
making a lateral electric contact pad between the first layer and the substrate, and
stack to said anodic treatment in an electrolyte.
2. The method according to claim 1 , wherein the anodic treatment is made under conditions such that the material of the first layer is transformed into porous material.
3. The method according to claim 1 , wherein the anodic treatment is made under conditions such that the material of the first layer is completely etched.
4. The method according to claim 1 , wherein the hole blocking layer and the second layer are formed from materials of the same nature.
5. The method according to claim 4 , wherein the hole blocking layer and the second layer are formed from N-doped semiconductor material having a dopant concentration less than 10 18 atoms/cm 3 .
6. The method according to claim 1 , comprising forming a first protective layer made from a material resistant to the electrolyte on the second layer of semiconductor material.
7. The method according to claim 6 , comprising forming a second protective layer made from an electrically insulating material resistant to the electrolyte on the lateral electric contact pad.
8. The method according to claim 1 , wherein the lateral electric contact pad is formed by ion implantation of N-type with a dopant concentration greater than or equal to 10 18 atoms/cm 3 or of P-type through a mask.
9. The method according to claim 1 , wherein the stack is laterally delineated by etching of the hole blocking layer and of the first and second layers through a mask.
10. The method according to claim 9 , wherein the lateral electric contact pad is formed by epitaxy of an N-doped semiconductor material with a dopant concentration greater than or equal to 10 18 atoms/cm 3 or P-type semiconductor material.
11. The method according to claim 9 , wherein the lateral electric contact pad is made by deposition of a metal layer.
12. The method according to claim 1 , wherein the lateral electric contact pad is arranged on both sides of the stack and is made from an N-doped semiconductor material with a dopant concentration greater than or equal to 10 18 atoms/cm 3 or P-type semiconductor material.
13. The method according to claim 1 , wherein the stack comprises more than one repetition of first and second layers made from semiconductor materials.