Methods and compositions for doping silicon substrates with molecular monolayers
Compositions and methods for doping silicon substrates by treating the substrate with a diluted dopant solution comprising tetraethylene glycol dimethyl ether (tetraglyme) and a dopant-containing material and subsequently diffusing the dopant into the surface by rapid thermal annealing. Diethyl-1-propylphosphonate and allylboronic acid pinacol ester are preferred dopant-containing materials, and are preferably included in the diluted dopant solution in an amount ranging from about 1% to about 20%, with a dopant amount of 4% or less being more preferred.
1. A method, comprising:
contacting a silicon-containing substrate with a dopant solution to form a layer of dopant-containing material on the silicon-containing substrate, the dopant solution including a solvent and a dopant, wherein the dopant solution has a flash point greater than 120° C.
2. The method of claim 1 , wherein the dopant includes one or more elements of Group III of the Periodic Table, one or more elements of Group V of the Periodic Table, or a combination thereof.
3. The method of claim 1 , wherein the silicon-containing substrate includes crystalline silicon.
4. The method of claim 1 , further comprising cleaning the silicon-containing substrate to remove oxides before contacting the silicon-containing substrate with the dopant solution.
5. The method of claim 1 , further comprising treating the silicon-containing substrate with 3-methyl-3-methoxybutanol.
6. The method of claim 1 , further comprising applying a capping layer to the silicon-containing substrate after contacting the silicon-containing substrate with the dopant solution.
7. The method of claim 6 , wherein the capping layer has a thickness of about 50 nm.
8. The method of claim 6 , wherein the capping layer is applied by plasma enhanced chemical vapor deposition.
9. The method of claim 1 , further comprising annealing the silicon-containing substrate to diffuse the dopant into the silicon-containing substrate.
10. The method of claim 1 , wherein dopant solution comprises one or more than one solvent, and each individual solvent present has a flash point of 120C or more.
11. A method, comprising:
contacting a surface including crystalline silicon with a dopant solution to form a layer of dopant-containing material on the surface, the dopant solution including a solvent and a dopant, wherein the solvent comprises tetraethylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dimethylsulfoxide, dimethylsulfone, N-methylpyrrolidone, 1-formyl piperidine, Isopar M, ethanolamine, diethanolamine, triethanolamine, linoleic acid, oleic acid, palmitoleic acid, safflower oil, grape seed oil, poppyseed oil, sunflower oil, hemp oil, corn oil, wheat germ oil, cottonseed oil, soybean oil, walnut oil, sesame oil, rice bran oil, pistachio oil, peanut oil, canola oil, chicken fat, egg yolk, linseed oil, lard, olive oil, palm oil, cocoa butter, macadamia oil, butter, coconut oil, or combinations thereof.
12. The method of claim 11 , wherein an amount of the dopant in the dopant solution is included in a range of 1 wt % to 20 wt % of a total weight of the dopant solution.
13. The method of claim 11 , wherein the dopant solution includes less than 4 wt % of the dopant for a total weight of the dopant solution.
14. The method of claim 11 , wherein the dopant solution has a contact angle of 0° when applied to the surface.
15. The method of claim 11 , wherein the dopant includes arsenic, gallium, boron, phosphorus, or a combination thereof.
16. The method of claim 11 wherein dopant solution comprises one or more than one solvent, and each individual solvent present has a flash point of 120C or more.
17. A method comprising:
contacting a silicon-containing surface with a dopant solution to form a layer of dopant-containing material on the silicon-containing surface, the dopant solution including a solvent and arsenic-containing molecules, wherein said solvent comprises tetraethylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dimethylsulfoxide, dimethylsulfone, N-methylpyrrolidone, 1-formyl piperidine, Isopar M, ethanolamine, diethanolamine, triethanolamine, linoleic acid, oleic acid, palmitoleic acid, safflower oil, grape seed oil, poppyseed oil, sunflower oil, hemp oil, corn oil, wheat germ oil, cottonseed oil, soybean oil, walnut oil, sesame oil, rice bran oil, pistachio oil, peanut oil, canola oil, chicken fat, egg yolk, linseed oil, lard, olive oil, palm oil, cocoa butter, macadamia oil, butter, coconut oil, or combinations thereof.
18. The method of claim 17 , wherein the solvent is one of a plurality of solvents of the dopant solution.
19. The method of claim 17 , wherein a flash point of the dopant solution is greater than 120° C.
20. The method of claim 17 , wherein the dopant solution is miscible in water.
21. The method of claim 17 , wherein the contacting the silicon-containing surface with the dopant solution includes immersing a silicon substrate containing crystalline silicon in the dopant solution.
22. The method of claim 17 wherein dopant solution comprises one or more than one solvent, and each individual solvent present has a flash point of 120C or more.