Directional gas injection for an ion source cathode assembly
AssigneeVarian Semiconductor Equipment Associates, Inc.
InventorsJohn Bon-Woong Koo, David J. Twiss, Chris Campbell, Frank Sinclair, Alexander S. Perel, Craig R. Chaney, Wilhelm P. Platow, Eric R. Cobb
Life of this patent
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Abstract
In an ion implanter, an inert gas is directed at a cathode assembly near an ion source chamber via a supply tube. The inert gas is provided with a localized directional flow toward the cathode assembly to reduce unwanted concentrations of cleaning or dopant gases introduced into the ion source chamber, thereby reducing the effects of unwanted filament growth in the cathode assembly and extending the manufacturing life of the ion source.
Claims16
An ion source assembly comprising:
- an ion source chamber configured to receive a first gas;
- an indirectly heated cathode having a filament and a cathode located at a first end of said ion source chamber;
- and
- a supply tube proximate said filament configured to provide a second gas toward said filament and said cathode such that a pressure of said first gas is reduced near said filament, said filament and said cathode configured to be powered when the second gas is provided toward said filament.
A method of directional gas injection in an ion source chamber of an ion implanter comprising:
- introducing a first gas into said ion source chamber;
- ionizing said first gas within said chamber by using an indirectly heated cathode having a filament and a cathode;
- supplying a second gas directed at said filament when said cathode and said filament are powered;
- and
- using said second gas to reduce a pressure of said first gas near said filament.
An ion source assembly comprising:
- an ion source chamber configured to receive a first gas;
- an indirectly heated cathode having a filament and a cathode located at a first end of said ion source chamber, said filament located outside of said ion source chamber within a region defined by said cathode and configured to heat said cathode to emit thermo electrons into the ion source chamber;
- and
- a supply tube proximate said filament and said cathode, said supply tube configured to provide a second gas toward said region such that a pressure of said first gas is reduced near said filament, said filament and said cathode configured to be powered when the second gas is provided toward said filament.
Dependencies are inferred from the claim text.