Dopant precursors for mono-layer doping
View Patent ↗A doping process is described, which includes applying to a substrate a film of dopant material that bonds to the substrate by at least one of hydrogen bonding and covalent bonding; encapsulating the film on the substrate with an encapsulant material, and subjecting the encapsulated film to rapid thermal processing to cause dopant from the dopant material to migrate into the substrate. The film of dopant material is applied from a dopant composition selected from among: (i) dopant compositions comprising an aqueous or glycol solution comprising an inorganic dopant compound; (ii) dopant compositions comprising an arsenic, phosphorus, boron, or antimony compound in which ligands or moieties coordinated to an arsenic, phosphorus, boron, or antimony central atom have coordination bond energies that are lower than those associated with coordinating bonds of said central atom to oxygen or carbon; (iii) dopant compositions comprising a coordinated moiety that selectively and covalently bonds to the substrate; (iv) dopant compositions comprising a compound that undergoes hydrolysis and alcoholysis to covalently bond a dopant functionality to the substrate in said film of dopant material; (v) dopant compositions comprising precursor vapor of an organodopant compound; (vi) dopant compositions interactive with a surface functionality of the substrate to bind the dopant composition to the substrate, wherein the substrate comprises a silicon surface comprising said surface functionality; (vii) dopant compositions interactive with the substrate to covalently bond with a pretreated and/or modified silicon surface thereof; and (viii) dopant compositions interactive with the substrate to bond with the substrate on a silicon surface thereof that has been modified by a treatment comprising at least one of: (A) contacting the silicon surface with a chemical solution; (B) exposing the silicon surface to plasma; and (C) exposing the silicon surface to ultraviolet radiation.
1. A doping process, comprising: applying to a substrate a film of dopant material that bonds to the substrate by at least one of hydrogen bonding and covalent bonding; encapsulating the film on the substrate with an encapsulant material, and subjecting the encapsulated film to rapid thermal processing to cause dopant from the dopant material to migrate into the substrate, wherein the film of dopant material is applied from a dopant composition comprising a coordinated moiety that selectively and covalently bonds to the substrate, wherein the dopant composition comprises a compound selected from the group consisting of:
or
wherein P(As) is phosphorous or arsenic, and R is an organo moiety.
2. The process of claim 1 , wherein the substrate comprises a silicon substrate, a SiGe substrate, a germanium substrate, or a germanium tin substrate.
3. The process of claim 1 , wherein the film comprises a monolayer film.
4. The process of claim 1 , wherein the film of dopant material is applied from a dopant composition comprising an aqueous solution comprising an inorganic arsenic compound.
5. The process of claim 4 , wherein the inorganic arsenic compound comprises As 2 O 3 .
6. The process of claim 5 , wherein the film of dopant material comprises at least a partial molecular layer of arsenic formed by chemical reaction comprising the following reaction, or partial reaction:
3(≡Si—H)+As(OH) 3 →(≡Si) 3 As+3H 2 O.
7. The process of claim 5 , wherein the film of dopant material comprises at least a partial molecular layer of arsenic formed by chemical reaction comprising the following reaction, or partial reaction:
3(≡Si—OH)+O═As(OR) 3 →(≡Si—O) 3 As═O+3ROH.
8. The process of claim 5 , wherein the film of dopant material comprises at least a partial molecular layer of arsenic formed by chemical reaction comprising the following reaction, or partial reaction:
3(≡Si—NH)+O═As(OR) 3 →(≡Si—N) 3 As═O+3ROH.
9. The process of claim 1 , wherein the film of dopant material is applied from a dopant composition comprising an arsenic or phosphorous compound in which ligands or moieties coordinated to an arsenic or phosphorous central atom have coordination bond energies that are lower than those of coordinating bonds of said central atom to oxygen or carbon.
10. The process of claim 1 , wherein the dopant composition comprises dodecylphosphonic acid.
11. The process of claim 1 , wherein the film of dopant material is applied from a dopant composition comprising a compound that undergoes hydrolysis and alcoholysis to covalently bond a dopant functionality to the substrate in said film of dopant material.
12. The process of claim 11 , wherein the compound comprises triethyl arsenate.
13. The process of claim 1 , wherein the film of dopant material is applied to the substrate from a liquid solution of dopant precursor.
14. The process of claim 1 , wherein the film of dopant material is applied to the substrate from a dopant precursor vapor.
15. The process of claim 1 , wherein the film of dopant material is applied from a dopant composition comprising a glycol solution comprising an inorganic arsenic compound.
16. The process of claim 1 , wherein the film of dopant material is applied from a dopant composition comprising an aqueous solution comprising an inorganic phosphorus compound.
17. The process of claim 1 , wherein the dopant composition comprises precursor vapor of an organodopant compound.
18. The process of claim 17 , wherein the organodopant compound comprises an arsenic compound selected from the group consisting of As(Et) 3 , As(Me) 3 , and As(NMe 2 ) 3 , wherein Et is ethyl and Me is methyl.