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 and further comprising use of an extraction electrode to provide a collimated ion beam of said boron-containing ions for implantation in said substrate.
2. The method of claim 1 ,
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.
3. The method of claim 2 , further comprising storing the boron-containing composition in a storage and delivery vessel containing a pressure regulator in an interior volume of the vessel.
4. The method of claim 2 , wherein the substrate comprises a microelectronic device substrate.
5. The method of claim 2 , wherein the boron-containing ions are implanted in the substrate to form a shallow p-type doped region in the substrate.
6. The method of claim 2 , wherein the ionizing is conducted at an arc voltage of less than 100 volts.
7. The method of claim 2 , wherein noble gas is mixed with the boron-containing composition in said ionizing or prior to said ionizing.
8. The method of claim 7 , wherein the noble gas is neon, argon, or krypton.
9. The method of claim 2 , wherein said ionizing comprises cleavage of B 2 F 4 at its B—B bond.
10. The method of claim 9 , 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.
11. The method of claim 2 , wherein the boron-containing composition further comprises BF 3 .
12. The method of claim 2 , 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.
13. The method of claim 2 , wherein the boron-containing ions are implanted in the substrate to form a p-type doped region in the substrate.
14. The method of claim 1 ,
wherein the boron-containing composition further comprises BF 3 and wherein the boron-containing composition further comprises less than 20 percent by weight BF 3 .
15. A method of implanting boron-containing ions in the manufacture of a microelectronic device, comprising:
supplying B 2 F 4 from a supply vessel to an ion implanter tool;
ionizing said B 2 F 4 in said ion implantation tool to generate boron-containing ions;
operating an extraction electrode of said ion implantation tool to cause said boron-containing ions to pass through an aperture as a collimated ion beam; and
accelerating the collimated ion beam by electric field to implant boron-containing ions in a substrate for said microelectronic device.
16. The method of claim 15 , further comprising at least one of:
(i) conducting said ionizing at an arc voltage of less than 90 volts;
(ii) introducing a fluorine-containing species to said ionizing;
(iii) introducing a noble gas to said ionizing; and
(iv) conducting said ionizing at an ionization efficiency of at least 15%.