Method of implanting low doses of ions into a substrate
AssigneeEaton Corporation
InventorMatthew C. Gwinn
Life of this patent
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Abstract
The present invention provides for an ion implantation system that employs an ion source for ionizing and implanting into a substrate a noble diluent gas and a particular dopant gas. The noble diluent gas of the present invention preferably does not react with the dopant gas, or with dopant residue which coats the walls of the ionization chamber of the ion source, thus allowing the ion source to be used for accurate, stable low dose implants. Additionally, the noble diluent gas does not introduce conductivity altering ions, or impurities, into the substrate S. Consequently, the dosage of the dopant ions implanted into the substrate can be precisely controlled, especially in low dose applications.
Claims19
A method for ionizing a selected gas mixture in an ion source and for performing a low dose implant on a substrate, comprising the steps of
- introducing a dopant gas and a noble diluent gas which intermingles with the dopant gas into an ionization chamber of an ion source, the noble gas being inert relative to the selected gas,
- ionizing the dopant gas and the noble diluent gas,
- emitting an ion beam from the ion source, said ion beam including ions of both said dopant gas and noble diluent gases,
- implanting low doses of both the dopant ions and the diluent ions into the substrate, and
- controlling the dosage of said dopant ions during said low dose implant with said noble diluent gas.
A method for implanting low doses of ions into a substrate, comprising the steps of
- introducing a dopant gas and a noble diluent gas into an ionization chamber of an ion source, the noble diluent gas being inert relative to the dopant gas,
- ionizing the selected dopant gas and the noble diluent gas when disposed in the ionization chamber to form dopant ions and diluent ions,
- implanting low doses of both the dopant ions and the diluent ions into the substrate, and
- controlling the dosage of said dopant ions during said low dose implant with said noble diluent gas, thereby implanting low doses of said dopant ions without introducing conductivity altering impurities other than said dopant ions into the substrate during said implant.
An ion implantation system for implanting low doses of ions into a substrate, the system comprising
- an ion source having an ionization chamber,
- an implantation housing coupled to the ion source and having an implantation chamber sized to house the substrate,
- one or more fluid reservoirs containing a noble diluent gas and a dopant gas,
- gas introduction means for introducing the dopant gas and the noble diluent gas into the ionization chamber, the noble diluent gas intermingling with the dopant gas therein,
- means for ionizing the dopant gas and the diluent gas when disposed within the ionization chamber to form energized ions,
- means for implanting low doses of the energized dopant ions and diluent ions into the substrate when positioned within the implantation chamber and in the path of the ions, and
- control means for controlling the dosage of said dopant ions with the noble diluent gas to achieve said low dose implant without introducing conductivity altering impurities other than said dopant ions into the substrate during said implant.
A method for performing a low dose implant on a substrate, comprising the steps of
- introducing a dopant gas and a noble diluent gas which intermingles with the dopant gas into an ionization chamber of an ion source, the noble gas being inert relative to the selected gas,
- ionizing the dopant gas and the noble diluent gas,
- emitting an ion beam from the ion source, said ion beam including ions of said dopant and noble diluent gases,
- implanting low doses of the dopant ions and the diluent ions into the substrate, and
- stabilizing the ratio of dopant ions to the total number of ions in said ion beam to achieve accurate, stable low dose implants.
Dependencies are inferred from the claim text.