Method for fabricating silicon and/or germanium nanowires
The invention relates to a method for fabricating silicon and/or germanium nanowires on a substrate, comprising a step of bringing a precursor comprising silicon and/or a precursor comprising germanium into contact with a compound comprising copper oxide present on the said substrate, by means of which growth of nanowires takes place.
1. A method for fabricating silicon and/or germanium nanowires on a substrate, comprising:
a step of contacting a precursor comprising silicon and/or a precursor comprising germanium in contact with a compound comprising copper oxide present on said substrate, by means of which growth of nanowires takes place, said substrate being a silicon substrate, optionally covered with a barrier layer against the diffusion of copper present in said compound,
said step of contacting consisting of passing a stream of precursor comprising silicon and/or precursor comprising germanium over the compound comprising copper oxide, with a flow rate and for a time which are effective for obtaining growth of nanowires based on silicon and/or germanium.
2. The method according to claim 1 , in which the barrier layer is made of a metal, a metal nitride or a mixture thereof.
3. The method according to claim 1 , in which the barrier layer is made of tantalum, tantalum nitride, titanium nitride, or a mixture thereof.
4. The method according to claim 1 , in which the compound comprising copper oxide is in the form of particles which are separate from one another.
5. The method according to claim 1 , in which the compound comprising copper oxide consists of copper oxide on its own or a mixture of the metallic copper and copper oxide.
6. The method according to claim 1 , further comprising, before the contact step, a step of fabricating the compound comprising copper oxide on the substrate.
7. The method according to claim 6 , in which the fabrication step consists of depositing the compound comprising copper oxide directly on the substrate.
8. The method according to claim 6 , in which the fabrication step consists of first depositing metallic copper or copper in oxidation state zero on said substrate and then, second, fully or partially oxidizing the metallic copper to form copper oxide.
9. The method according to claim 8 , in which the oxidation step consists of passing a stream of oxygen over the metallic copper deposited on said substrate.
10. The method according to claim 1 , in which the precursor comprising silicon is silane SiH 4 , disilane Si 2 H 6 , trisilane Si 3 H 8 or a halosilane SiX 4 , X being a halogen atom.
11. The method according to claim 1 , in which the precursor comprising germanium is germane GeH 4 , digermane Ge 2 H 6 or trigermane Ge 3 H 8 .
12. The method according to claim 1 , in which the precursor comprising silicon and/or the precursor comprising germanium is diluted with a neutral carrier gas and/or a reducing gas.
13. The method according to claim 1 , in which, during the contact step, a doping agent is brought into contact with the precursor comprising silicon and/or the precursor comprising germanium.
14. The method according to claim 1 , in which the stream of precursor comprising silicon and/or precursor comprising germanium is in the form of a plasma.
15. The method according to claim 1 , in which the contact step is carried out at a temperature of less than 450° C.