US 6,803,585 B2Granted

Electron-cyclotron resonance type ion beam source for ion implanter

OwnerYuri Glukhoyinventor

Life of this patent

Estimating the term…

Loading patent…

Abstract

An ECR ion-beam source for use in an ion implanter has a sealed plasma chamber in which plasma is excited by microwave radiation of 2.45 GHz in combination with an external magnetic field generated by permanent magnets surrounding the plasma chamber. The magnets cause electron-cyclotron resonance for the electrons of the plasma thus creating conditions for efficient absorption of the microwave energy. The same magnets generate a magnetic field, which compresses the plasma toward the center for confining the plasma within the plasma chamber. The ion source also has an RF pumping unit that pumps into the plasma the RF energy. The RF pumping unit has a unique additional function of RF magnetron sputtering of solid targets converted into a gaseous working medium used for implantation in an ionized form. For obtaining elongated belt-type ion beams (having a width of 1 m or longer), the ion source may contain a microwave pumping system having several output windows arranged in series along the axis of the plasma chamber and on diametrically opposite sides thereof. The windows are continuously cleaned from the contaminants that might precipitate onto their surfaces. A standard-type sand blaster can be used for cleaning of the windows.

Claims25

Dependent claims

An electron cyclotron resonance type ion source comprising:

a hollow housing, which functions as an anode and is maintained under high voltage, said housing being made of a non-magnetic material;
a source of electric power having a negative terminal and a positive terminal, said positive terminal being connected to hollow housing for applying said high voltage, said negative terminal of said source of electric power being grounded, the interior of said sealed hollow housing forming a plasma-confining cavity having an axial length;
permanent magnetic field generation means for generating a permanent magnet field within said plasma-confining cavity for confining a plasma, formed in said plasma-confining cavity, in a radial inward direction;
microwave energy generation means with a frequency satisfying a condition of electron-cyclotron resonance consumption of microwave energy by said plasma, said microwave energy generation means comprising at least two individual microwave generators and at least two microwave energy pumping units, respectively, for supplying microwave energy into said plasma-confining cavity, said microwave energy having a frequency required for said condition of electron-cyclotron resonance consumption for electrons of said plasma;
at least one window extending in the direction of said axial length, said window being transparent to said microwave energy of said microwave energy pumping units for passing said microwave energy to said plasma-confining cavity, said at least one window having means for sealing said plasma-confining cavity;
RF energy supply means for supplying RF energy to said plasma-confining cavity;
means for the supply of a gaseous medium into said sealed hollow housing;
ion-beam formation and extraction means for forming an ion beam and extracting said ion beam from said plasma;
and means for cleaning said at least one window from contamination.

6 more elements

A method of generating an ion beam for use in an ion implanter, comprising the steps of:

providing an ion-beam source comprising a sealed plasma-confining cavity having an axial length, evacuating means for evacuating said sealed plasma-confining cavity, gaseous medium supply means for supplying a gaseous medium into said plasma-confining means, magnetic field generating means for generating a magnetic field in said sealed plasma-confining cavity, microwave energy pumping means for pumping a microwave energy into said sealed plasma-confining cavity, at least one window extending substantially along said axial length of said plasma-confining cavity and sealing said plasma-confining cavity, said at least one window being transparent to said microwave energy generated by said microwave energy pumping means, RF energy pumping means for pumping RF energy into said plasma-confining cavity, and means for cleaning said at least one window from contaminants;
evacuating said sealed plasma-confining cavity by said evacuating means;
supplying a gaseous medium into said sealed plasma-confining cavity by said gaseous medium supply means;
generating a magnetic field in said sealed plasma-confining cavity by said magnetic field generating means;
pumping a microwave energy into said sealed plasma-confining cavity by said microwave energy pumping means via said at least one window;
pumping RF energy into said plasma-confining cavity by said RF energy pumping means;
developing conditions of electron-cyclotron resonance consumption of said microwave energy in said sealed plasma-confining cavity;
generating a gaseous plasma in said gaseous medium in said sealed plasma-confining cavity;
extracting ions from said plasma in a radial outward direction of said plasma-confining cavity and forming an ion beam for use in said ion implanter;
and cleaning said windows from said contaminants.

7 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/032,425Filed 31 Dec 2001 · continuation
Priority: 3 Jan 2000
Published: US 2003/0234369 A125 Dec 2003
Granted: 12 Oct 2004
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

H01J 27/18
Using high-frequency excitation, e.g. microwave excitation: with an applied axial magnetic field
H01J 37/08
Arrangements of electrodes and associated parts for generating or controlling the discharge, e.g. electron-optical arrangement or ion-optical…:…
H01J 2237/0817
Methods of ionisation: microwaves
H01J 2237/31701
Processing objects on a microscale: ion implantation