Enriched silicon precursor compositions and apparatus and processes for utilizing same
View Patent ↗Isotopically enriched silicon precursor compositions are disclosed, as useful in ion implantation to enhance performance of the ion implantation system, in relation to corresponding ion implantation lacking such isotopic enrichment of the silicon precursor composition. The silicon dopant composition includes at least one silicon compound that is isotopically enriched above natural abundance in at least one of 28 Si, 29 Si, and 30 Si, and may include a supplemental gas including at least one of a co-species gas and a diluent gas. Dopant gas supply apparatus for providing such silicon dopant compositions to an ion implanter are described, as well as ion implantation systems including such dopant gas supply apparatus.
1. A dopant gas composition supply for ion implantation of silicon, said supply being selected from the group consisting of:
(A) a gas storage and dispensing vessel containing a silicon dopant composition comprising silicon dopant gas in mixture with supplemental gas comprising at least one of a diluent gas and a co-species gas, wherein the silicon dopant composition comprises at least one gaseous silicon compound that is isotopically enriched above natural abundance in at least one of 28 Si, 29 Si, and 30 Si; and
(B) a gas supply kit comprising (i) a first gas storage and dispensing vessel containing silicon dopant gas, and (ii) a second gas storage and dispensing vessel holding supplemental gas comprising at least one of a diluent gas and a co-species gas, wherein at least one of the silicon dopant gas and, when present, a co-species gas, is isotopically enriched above natural abundance in at least one of 28 Si, 29 Si, and 30 Si.
2. The dopant gas composition supply according to claim 1 , comprising a silicon compound selected from the group consisting of silicon tetrafluoride (SiF 4 ), silane (SiH 4 ), disilane (Si 2 H 6 ), C 1 -C 8 alkylsilanes, fluorosilanes, and chlorosilanes.
3. The dopant gas composition supply according to claim 2 , wherein said silicon compound is isotopically enriched above natural abundance in 28 Si.
4. The dopant gas composition supply according to claim 3 , wherein said silicon compound comprises silicon tetrafluoride, isotopically enriched in 28 Si in a range of concentration that is greater than 92.3 atomic % and up to 100 atomic %.
5. The dopant gas composition supply according to claim 4 , wherein said silicon tetrafluoride is homoisotopic in 28 Si.
6. The dopant gas composition supply according to claim 1 , wherein said supplemental gas comprises a diluent gas selected from the group consisting of argon, hydrogen, fluorine, krypton, neon, helium, ammonia, amines, water, phosphine, arsine, germane, hydrogen selenide, hydrogen sulfide, nitrogen, oxygen, carbon monoxide, xenon difluoride, diborane, methane, and xenon.
7. The dopant gas composition supply according to claim 1 , wherein the dopant gas composition comprises a gas composition selected from the group consisting of:
(i) isotopically enriched silicon tetrafluoride with xenon and hydrogen;
(ii) isotopically enriched silicon tetrafluoride with silane;
(iii) isotopically enriched silicon tetrafluoride and isotopically enriched silane;
(iv) isotopically enriched silicon tetrafluoride with argon;
(v) isotopically enriched silicon tetrafluoride with disilane;
(vi) isotopically enriched silicon tetrafluoride and isotopically enriched disilane;
(vii) isotopically enriched silicon tetrafluoride with hydrogen;
(viii) isotopically enriched silicon tetrafluoride with ammonia;
(ix) isotopically enriched silicon tetrafluoride with ammonia and xenon;
(x) isotopically enriched silicon tetrafluoride with hydrogen and krypton;
(xi) isotopically enriched silicon tetrafluoride with ammonia and krypton;
(xii) isotopically enriched silicon tetrafluoride with nitrogen;
(xiii) isotopically enriched silicon tetrafluoride with nitrogen and xenon;
(xiv) isotopically enriched silicon tetrafluoride with nitrogen and krypton; and
(xv) isotopically enriched silicon tetrafluoride with one or more of the following: hydrogen, nitrogen, ammonia, xenon, and argon.
8. The dopant gas composition supply according to claim 1 (A).
9. The dopant gas composition supply according to claim 1 (B).
10. An ion implantation system, comprising an ion implanter arranged in gas-receiving flow communication with a dopant gas composition supply according to claim 1 .
11. The ion implantation system of claim 10 , wherein the ion implanter is adapted to:
(A) ionize the silicon dopant composition from said dopant gas composition supply and form ionized silicon, and to contact the ionized silicon with a substrate to implant silicon therein; and
(B) (i) generate an ion beam of said ionized silicon, and accelerate the ion beam by electric field to the substrate for implantation of silicon therein, or (ii) conduct a plasma immersion process for implantation of silicon in the substrate.
12. A method for enhancing operation of an ion implantation system, comprising providing for use in the ion implantation system a dopant gas composition supply according to claim 1 .
13. The method of claim 12 , wherein the dopant gas composition supply comprises a silicon compound selected from the group consisting of silicon tetrafluoride (SiF 4 ), silane (SiH 4 ), disilane (Si 2 H 6 ), C 1 -C 8 alkylsilanes, fluorosilanes, and chlorosilanes.
14. The method of claim 13 , wherein said silicon compound comprises silicon tetrafluoride (SiF 4 ), isotopically enriched above natural abundance in 28 Si, in a range of concentration that is greater than 92.3 atomic % and up to 100 atomic %.
15. The method of claim 14 , wherein said silicon tetrafluoride is homoisotopic in 28 Si.
16. The method of claim 12 , wherein said supplemental gas comprises a diluent gas selected from the group consisting of argon, hydrogen, fluorine, krypton, neon, helium, ammonia, amines, water, phosphine, arsine, germane, hydrogen selenide, hydrogen sulfide, nitrogen, oxygen, carbon monoxide, xenon difluoride, diborane, methane, and xenon.
17. The method of claim 12 , wherein the dopant gas composition comprises a gas composition selected from the group consisting of:
(i) isotopically enriched silicon tetrafluoride with xenon and hydrogen;
(ii) isotopically enriched silicon tetrafluoride with silane;
(iii) isotopically enriched silicon tetrafluoride and isotopically enriched silane;
(iv) isotopically enriched silicon tetrafluoride with argon;
(v) isotopically enriched silicon tetrafluoride with disilane;
(vi) isotopically enriched silicon tetrafluoride and isotopically enriched disilane;
(vii) isotopically enriched silicon tetrafluoride with hydrogen;
(viii) isotopically enriched silicon tetrafluoride with ammonia;
(ix) isotopically enriched silicon tetrafluoride with ammonia and xenon;
(x) isotopically enriched silicon tetrafluoride with hydrogen and krypton;
(xi) isotopically enriched silicon tetrafluoride with ammonia and krypton;
(xii) isotopically enriched silicon tetrafluoride with nitrogen;
(xiii) isotopically enriched silicon tetrafluoride with nitrogen and xenon;
(xiv) isotopically enriched silicon tetrafluoride with nitrogen and krypton; and
(xv) isotopically enriched silicon tetrafluoride with one or more of the following: hydrogen, nitrogen, ammonia, xenon, and argon.