Systems and methods for nanowire growth and harvesting
View Patent ↗The present invention is directed to systems and methods for nanowire growth and harvesting. In an embodiment, methods for nanowire growth and doping are provided, including methods for epitaxial oriented nanowire growth using a combination of silicon precursors. In a further aspect of the invention, methods to improve nanowire quality through the use of sacrifical growth layers are provided. In another aspect of the invention, methods for transferring nanowires from one substrate to another substrate are provided.
1. A method of harvesting a nanowire, comprising the steps of:
(a) growing a desired portion of the nanowire;
(b) growing a sacrificial portion of the nanowire which is doped differently than the desired portion of the nanowire;
(c) differentially removing the sacrificial portion of the nanowire; and
(d) removing a growth stub from the desired portion of the nanowire.
2. The method of claim 1 , differentially removing the sacrificial portion of the nanowire includes using a wet etchant to selectively remove the sacrificial portion of the nanowire based on the type of doping used within the sacrificial portion of the nanowire.
3. The method of claim 1 , wherein the sacrificial portion of the nanowire in n-doped and the desired portion of the nanowire is p-doped.
4. The method of claim 1 , wherein the sacrificial portion of the nanowire is p-doped and the desired portion of the nanowire is n-doped.
5. The method of claim 4 , wherein boron is used as a dopant to grow the sacrificial portion of the nanowire.
6. The method of claim 2 , wherein differently removing the sacrificial portion of the nanowire includes using Potassium Hydroxide (KOH), tetramethylammonium hydroxide (TMAH), or ethylene diamin/pyrocatecol/water (EDP).
7. The method of claim 1 , wherein the sacrificial portion of the nanowire is not doped and the desired portion of the nanowire is p-doped.
8. The method of claim 1 , wherein the desired portion of the nanowire includes Si or Ge.
9. The method of claim 1 , wherein the sacrificial portion of the nanowire is not doped and the desired portion of the nanowire includes a portion which is n-doped.
10. The method of claim 1 , wherein the sacrificial portion of the nanowire is n-doped and the desired portion of the nanowire includes a portion which is p-doped.