Inorganic phosphate containing doping compositions
View Patent ↗A composition for doping semiconductor materials, such as silicon, may contain a) a solvent and a) an inorganic salt of a phosphor containing acid dispersed in the solvent. Also disclosed are doping methods using such composition as well as methods of making the doping composition.
1. A semiconductor doping method comprising:
(A) obtaining a substrate comprising a semiconductor material and
(B) contacting at least a portion of a surface of the substrate with a non-aqueous doping composition comprising a) an organic solvent and b) an inorganic salt dispersed in said solvent, wherein the salt is selected from the group consisting of Al(H 2 PO 4 ) 3 , Al(PO 3 ) 3 , Ca 3 (PO 4 ) 2 , CaHPO 4 , Ca(H 2 PO 4 ) 2 , Ca 2 P 2 O 7 , MgHPO 4 , Mg 3 (PO 4 ) 2 , Zr(HPO 4 ) 2 , Na 4 P 2 O 7 and combinations thereof.
2. The method of claim 1 , wherein the substrate comprises silicon.
3. The method of claim 1 , wherein the doping composition is a non-Newtonian fluid.
4. The method of claim 1 , wherein the doping composition does not comprise a phosphor-containing acid or a phosphorous oxide.
5. The method of claim 1 , wherein the solvent is selected from the group consisting of alcohols, aldehydes, ketones, carboxylic acids, esters, amines, organosiloxanes, halogenated hydrocarbons, hydrocarbons and combinations thereof.
6. The method of claim 1 , wherein the doping composition further comprises a binding polymer.
7. The method of claim 6 , wherein said binding polymer is selected from polyacrylates, polyacetals, polyvinyls, cellulose, cellulose ethers and esters, and copolymers thereof.
8. The method of claim 1 , wherein the doping composition further comprises a matrix material.
9. The method of claim 8 , wherein the matrix material comprises nanoparticles.
10. The method of claim 1 further comprising heating the substrate, wherein said heating results in diffusing of phosphorous atoms of the inorganic salt into the substrate.
11. The method of claim 1 , wherein said contacting comprises printing the doping composition on the at least portion of the surface of the substrate.
12. The method of claim 11 , wherein said printing comprises screen printing.
13. The method of claim 1 , wherein said contacting is such that a first portion of the surface of the substrate is covered by the doping composition, while a second portion of the surface of the substrate is not covered by the doping composition.
14. The method of claim 13 further comprising heating the substrate, wherein the heating results in doping the first portion of the surface of the substrate with phosphorous atoms of the inorganic salt and wherein the second portion of the surface of the substrate is not doped.
15. A semiconductor doping method comprising:
(A) obtaining a substrate comprising a semiconductor material and
(B) contacting at least a portion of a surface of the substrate with a non-aqueous doping composition comprising a) an organic solvent, b) an inorganic salt dispersed in said solvent and c) a binding polymer, wherein the salt is selected from the group consisting of Al(H 2 PO 4 ) 3 , A 1 (PO 3 ) 3 , Ca 3 (PO 4 ) 2 , CaHPO 4 , Ca(H 2 PO 4 ) 2 , Ca 2 P 2 O 7 , MgHPO 4 , Mg 3 (PO 4 ) 2 , Zr(HPO 4 ) 2 , Na 4 P 2 O 7 and combinations thereof, and wherein the doping composition is a non-Newtonian fluid.