Boron ion implantation using alternative fluorinated boron precursors, and formation of large boron hydrides for implantation
View Patent ↗Methods of implanting boron-containing ions using fluorinated boron-containing dopant species that are more readily cleaved than boron trifluoride. A method of manufacturing a semiconductor device including implanting boron-containing ions using fluorinated boron-containing dopant species that are more readily cleaved than boron trifluoride. Also disclosed are a system for supplying a boron hydride precursor, and methods of forming a boron hydride precursor and methods for supplying a boron hydride precursor. In one implementation of the invention, the boron hydride precursors are generated for cluster boron implantation, for manufacturing semiconductor products such as integrated circuitry.
1. A method of implanting boron-containing ions, comprising:
ionizing a boron-containing composition comprising B 2 F 4 under ionization conditions to generate boron-containing ions; and
accelerating the boron-containing ions by electric field to implant boron-containing ions in a substrate,
wherein the ionizing is conducted in a vacuum chamber containing an ion source and wherein another fluorine-containing species is introduced to said ionizing, to assist with cleaning of the vacuum chamber during said ionizing, and wherein the ionizing is conducted at an arc voltage of less than 100 volts.
2. The method of claim 1 , wherein the substrate comprises a microelectronic device substrate.
3. The method of claim 1 , wherein the boron-containing ions are implanted in the substrate to form a shallow p-type doped region in the substrate.
4. The method of claim 1 , wherein the boron-containing ions are implanted in the substrate to form a p-type doped region in the substrate.
5. The method of claim 1 , wherein noble gas is mixed with the boron-containing composition in said ionizing or prior to said ionizing.
6. The method of claim 1 , wherein said ionizing comprises cleavage of B 2 F 4 at its B—B bond.
7. The method of claim 6 , wherein the cleavage of B 2 F 4 at its B—B bond produces BF 2 + molecular ions as said boron-containing ions, and said BF 2 + molecular ions are implanted in the substrate.
8. The method of claim 1 , wherein the boron-containing composition further comprises BF 3 .
9. The method of claim 8 , wherein the boron-containing composition further comprises less than 20 percent by weight BF 3 .
10. The method of claim 5 , wherein the noble gas is neon, argon, or krypton.
11. The method of claim 1 , wherein ionizing efficiency of the ionizing of said B 2 F 4 is at least 15%, and said ionizing is conducted at an arc voltage of less than 70 volts.
12. The method of claim 1 , further comprising annealing the substrate subsequent to implanting the boron-containing-ions in the substrate.
13. The method of claim 1 , wherein said substrate comprises an article selected from the group consisting of semiconductor substrates, substrates for flat panel displays, and substrates for microelectromechanical systems (MEMS).
14. The method of claim 1 , wherein said boron-containing composition is contained in a vessel in a gas box joined by a transfer line to a semiconductor tool in which the boron-containing ions are implanted in the substrate.
15. The method of claim 14 , wherein the transfer line contains a mass or pressure controller therein to modulate flow of the boron-containing composition to the semiconductor tool.
16. A method of implanting boron-containing ions, comprising:
ionizing two different boron-containing compounds to generate boron-containing ions; and
implanting the boron-containing ions in a substrate,
wherein said boron-containing compounds comprise B 2 F 4 and wherein another fluorine-containing species is introduced to said ionizing, and wherein the boron-containing compounds comprise a compound selected from the group consisting of nido-carboranes selected from the group consisting of CB 5 H 9 , C 2 B 4 H 8 , C 3 B 3 H 7 , C 4 B 2 H 6 and C 2 B 3 H 7 ; open cage carboranes selected from the group consisting of C 2 B 3 H 7 , CB 5 H 9 , C 2 B 4 H 8 , C 3 B 3 H 7 , C 4 B 2 H 6 and C 2 B 7 H 13 ; and closo-carboranes selected from the group consisting of C 2 B 3 H 5 , C 2 B 4 H 6 , C 2 B 5 H 7 , CB 5 H 7 , C 2 B 6 H 8 , C 2 B 7 H 9 , C 2 B 8 H 10 , C 2 B 9 H 11 and C 2 B 10 H 12 .
17. The method of claim 16 , wherein said ionizing is carried out using the ion source and said ion source comprises an ion source selected from the group consisting of ion sources of types using thermoelectrodes and powered by an electric arc, microwave types of ion sources using a magnetron, indirectly heated cathode sources, and RF plasma sources.
18. The method of claim 16 , wherein noble gas is introduced to said ionizing.
19. The method of claim 18 , wherein said noble gas is selected from the group consisting of neon and argon.
20. The method of claim 18 , wherein said noble gas is selected from the group consisting of krypton and xenon.