Phosphorus or arsenic ion implantation utilizing enhanced source techniques
Apparatus and method for use of solid dopant phosphorus and arsenic sources and higher order phosphorus or arsenic implant source material are described. In various implementations, solid phosphorus-comprising or arsenic-comprising materials are provided in the ion source chamber for generation of dimer or tetramer implant species. In other implementations, the ion implantation is augmented by use of a reactor for decomposing gaseous phosphorus-comprising or arsenic-comprising materials to form gas phase dimers and tetramers for ion implantation.
1. An ion implantation system, comprising:
an ion implanter comprising an ion source chamber; and
a reactor configured to receive gaseous phosphorus or arsenic dopant precursor material and form gaseous polyatomic phosphorus or gaseous polyatomic arsenic therefrom, wherein the reactor is constituted in or coupled in fluid communication with flow circuitry arranged to deliver gas phase material to the ion source chamber for ionization therein to form implant species for implantation in a substrate in the ion implanter, wherein the reactor is further configured to receive dopant precursor material and to decompose that precursor material to form solid arsenic or solid phosphorus in an accumulation mode within the reactor and, after a predetermined amount of solid elemental arsenic or phosphorus is accumulated, then to vaporize the solid elemental arsenic or phosphorus to yield gaseous arsenic or phosphorus in a polyatomic form.
2. The ion implantation system of claim 1 , further comprising a supply of gaseous phosphorus or arsenic dopant precursor material, wherein the system is arranged to dispense the supply to the flow circuitry.
3. The ion implantation system of claim 2 , wherein the supply of gaseous phosphorus or arsenic dopant precursor material comprises a supply of gaseous phosphorus dopant precursor material.
4. The ion implantation system of claim 2 , wherein the supply of gaseous phosphorus or arsenic dopant precursor material comprises a supply of gaseous arsenic dopant precursor material.
5. The ion implantation system of claim 1 , wherein the reactor contains internal media or components for enhanced heat transfer and/or residence time adjustment of gaseous material flowed therethrough.
6. The ion implantation system of claim 1 , wherein the reactor is constituted by a portion of the flow circuitry.
7. The ion implantation system of claim 1 , further comprising a heater configured to heat the flow circuitry to a temperature above condensation temperature of gas phase tetramer species therein.
8. The ion implantation system of claim 1 , further comprising a heat transfer member arranged to transfer heat from the ion source chamber to the flow circuitry.
9. The ion implantation system of claim 1 , further comprising a monitoring and control assembly configured to monitor beam current or a process condition affecting beam current, and to responsively modulate one or more of flow rate, temperature, and pressure in the system, to provide a predetermined beam current.
10. The ion implantation system of claim 1 , wherein the reactor is configured to produce gaseous polyatomic phosphorus or gaseous polyatomic arsenic in the form of gaseous dimer or gaseous tetramer phosphorus, or gaseous dimer or gaseous tetramer arsenic.
11. The ion implantation system of claim 1 , wherein the reactor is configured to decompose a phosphorus hydride or arsenic hydride dopant precursor material, to form corresponding solid elemental phosphorus or arsenic, and hydrogen, to produce gaseous polyatomic phosphorus or gaseous polyatomic arsenic as a gas phase dimer or tetramer material.
12. The ion implantation system of claim 1 , wherein the reactor has a layer of deposited and accumulated solid polyatomic phosphorus or arsenic.
13. The ion implantation system of claim 1 , wherein the reactor forms part of a means for receiving dopant precursor material and decomposing the precursor material to form solid arsenic or solid phosphorus in an accumulation mode within the reactor and, after a predetermined amount of solid elemental arsenic or phosphorus is accumulated, for vaporizing the solid elemental arsenic or phosphorus to yield gaseous arsenic or phosphorus in a polyatomic form.
14. An ion implantation system, comprising:
an ion implanter comprising an ion source chamber;
a supply of a phosphorus-comprising or arsenic-comprising gas phase precursor, wherein the supply is configured to dispense the precursor to the ion source chamber;
a monitoring and control assembly configured and programmed to operate the ion source chamber in a first phase of operation under conditions that deposit and accumulate solid polyatomic phosphorus or arsenic in the ion source chamber deriving from the precursor dispensed to the ion source chamber from said supply, and in a second phase of operation under conditions that generate vapors comprising dimers or tetramers from the deposited solid polyatomic phosphorus or arsenic for ion implantation.
15. The ion implantation system of claim 14 , wherein the ion source chamber comprises a first ion source chamber, and the ion implantation system comprises a second ion source chamber, configured to receive precursor dispensed from the supply and to operate in a same operational manner as the first ion source chamber but offset in operation so that the second ion source chamber is operated in the first phase of operation while the first ion source chamber is operated in the second phase of operation, and so that the second ion source chamber is operated in the second phase of operation while the first ion source chamber is operated in the first phase of operation.
16. The ion implantation system of claim 14 , wherein the supply of phosphorus-comprising or arsenic-comprising gas phase precursor comprise a supply of phosphorus-comprising gas phase precursor.
17. The ion implantation system of claim 14 , wherein the supply of phosphorus-comprising or arsenic-comprising gas phase precursor comprise a supply of arsenic-comprising gas phase precursor.
18. An ion implantation system, comprising:
an ion implanter comprising an ion source chamber;
a dopant source material supply assembly comprising one or more source vessels containing gaseous phosphorus or arsenic precursor compound, and configured to dispense the precursor compound for use in the ion implanter; and
a conversion assembly configured to convert dispensed gaseous phosphorus or arsenic precursor compound to gaseous polyatomic elemental phosphorus or arsenic material, and to provide the gaseous polyatomic elemental phosphorus or arsenic material for use in the ion source chamber to generate phosphorus or arsenic implantation species therefrom, wherein the conversion assembly comprises a monitoring and control assembly configured and programmed to operate the ion source chamber, in a first phase of operation, under conditions that deposit and accumulate solid polyatomic phosphorus or arsenic in the ion source chamber deriving from the precursor compound dispensed to the ion source chamber from said supply assembly and, in a second phase of operation, under conditions that generate vapors comprising dimers or tetramers from the deposited solid polyatomic phosphorus or arsenic for ion implantation.
19. The ion implantation system of claim 18 , wherein the conversion assembly comprises a reactor for thermally converting the dispensed gaseous phosphorus or arsenic precursor compound to the gaseous polyatomic elemental phosphorus or arsenic material.