Selective ion source
Abstract
A ion source is described wherein selected ions maybe extracted to the exclusion of unwanted ion species of higher ionization potential. Also described is a method of producing selected ions from a compound, such as P.sup.+ from PH.sub.3. The invention comprises a plasma chamber, an electron source, a means for introducing a gas to be ionized by electrons from the electron source, means for limiting electron energy from the electron source to a value between the ionization energy of the selected ion species and the greater ionization energy of an unwanted ion specie, and means for extracting the target ion specie from the plasma chamber. In one embodiment, the electrons are generated in a plasma cathode chamber immediately adjacent to the plasma chamber. A small extractor draws the electrons from the plasma cathode chamber into the relatively positive plasma chamber. The energy of the electrons extracted in this manner is easily controlled. The invention is particularly useful for doping silicon with P.sup.+, AS.sup.+, and B.sup.+ without the problematic presence of hydrogen, helium, water, or carbon oxide ions. Doped silicon is important for manufacture of semiconductors and semiconductor devices.
- Inventors:
-
- Hercules, CA
- Issue Date:
- Research Org.:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
- OSTI Identifier:
- 870418
- Patent Number(s):
- 5517084
- Assignee:
- Regents, University of California (Oakland, CA)
- Patent Classifications (CPCs):
-
H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01J - ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
H - ELECTRICITY H05 - ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR H05H - PLASMA TECHNIQUE
- DOE Contract Number:
- AC03-76SF00098
- Resource Type:
- Patent
- Country of Publication:
- United States
- Language:
- English
- Subject:
- selective; source; described; selected; extracted; exclusion; unwanted; species; ionization; potential; method; producing; compound; ph; comprises; plasma; chamber; electron; means; introducing; gas; ionized; electrons; limiting; energy; value; specie; extracting; target; embodiment; generated; cathode; immediately; adjacent; extractor; draws; relatively; positive; manner; easily; controlled; particularly; useful; doping; silicon; problematic; presence; hydrogen; helium; water; carbon; oxide; doped; manufacture; semiconductors; semiconductor; devices; electron energy; electron source; particularly useful; semiconductor device; semiconductor devices; doped silicon; plasma chamber; immediately adjacent; producing selected; easily controlled; ionization energy; ionization potential; /315/
Citation Formats
Leung, Ka-Ngo. Selective ion source. United States: N. p., 1996.
Web.
Leung, Ka-Ngo. Selective ion source. United States.
Leung, Ka-Ngo. Mon .
"Selective ion source". United States. https://www.osti.gov/servlets/purl/870418.
@article{osti_870418,
title = {Selective ion source},
author = {Leung, Ka-Ngo},
abstractNote = {A ion source is described wherein selected ions maybe extracted to the exclusion of unwanted ion species of higher ionization potential. Also described is a method of producing selected ions from a compound, such as P.sup.+ from PH.sub.3. The invention comprises a plasma chamber, an electron source, a means for introducing a gas to be ionized by electrons from the electron source, means for limiting electron energy from the electron source to a value between the ionization energy of the selected ion species and the greater ionization energy of an unwanted ion specie, and means for extracting the target ion specie from the plasma chamber. In one embodiment, the electrons are generated in a plasma cathode chamber immediately adjacent to the plasma chamber. A small extractor draws the electrons from the plasma cathode chamber into the relatively positive plasma chamber. The energy of the electrons extracted in this manner is easily controlled. The invention is particularly useful for doping silicon with P.sup.+, AS.sup.+, and B.sup.+ without the problematic presence of hydrogen, helium, water, or carbon oxide ions. Doped silicon is important for manufacture of semiconductors and semiconductor devices.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1996},
month = {1}
}