Method and apparatus for reducing substrate charging damage
AssigneeTokyo Electron Limited
InventorPaul Moroz
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Abstract
The present invention presents a method and apparatus for reducing charging damage to a substrate is described. In particular, a method of operating a plasma processing system is described that leads to the removal of, or significant reduction of, the accumulated charge on the substrate.
Claims86
A method for reducing charging damage to a substrate in a plasma processing system comprising the steps:
- coupling a first power to said plasma processing system to process said substrate using a first plasma;
- and
- coupling a second power to said plasma processing system, wherein said second power is selected to reduce the accumulation of negative charge on at least one surface of said plasma processing system arising from applying said first power.
A method for reducing negative charge on exposed surfaces within a plasma processing chamber comprising the steps:
- introducing an ionizable gas into said plasma processing chamber;
- and
- forming a plasma by coupling an intermediate power to said ionizable gas, wherein said intermediate power causes a secondary electron yield to be greater than unity from at least one of said exposed surfaces.
A method for reducing charging damage to a substrate in a plasma processing system comprising the steps:
- introducing an ionizable gas;
- forming a plasma from said ionizable gas;
- exposing said substrate to said plasma;
- and
- processing said substrate by coupling an intermediate power to said plasma processing system, wherein said intermediate power reduces the accumulation of negative charge on a substrate surface exposed to said plasma in said plasma processing system.
A method for reducing charging damage to a substrate in a plasma processing system comprising the steps:
- identifying at least one exposed surface in said plasma processing system;
- providing a secondary electron emitter surface on at least one of the at least one exposed surface, wherein said secondary electron emitter surface comprises a material having a secondary electron yield greater than unity for a range of energy levels;
- introducing an ionizable gas to said plasma processing system;
- forming a plasma from said ionizable gas;
- exposing a substrate to said plasma;
- and
- coupling said intermediate power to said plasma processing system to process said substrate, wherein said intermediate power corresponds to an energy level within said range of energy levels.
A plasma processing system for reducing charging damage to a substrate comprising:
- a plasma processing chamber to contain a plasma, said plasma processing chamber comprising at least one exposed surface in contact with said plasma;
- and
- at least one secondary electron emitter coupled to at least one of the at least one exposed surface, wherein said secondary electron emitter comprises a material having a secondary electron yield greater than unity.
A method for reducing charging damage to a substrate in a plasma processing system comprising the steps:
- exposing said substrate to a plasma;
- coupling a first power to said plasma processing system to process said substrate;
- and
- coupling a second power to said plasma processing system, wherein said second power is selected to reduce the accumulation of electric charge on one or more surfaces exposed to said plasma in said plasma processing system.
A method for reducing accumulated electric charge on exposed surfaces within a plasma processing system comprising the steps:
- introducing an ionizable gas;
- and
- applying an RF power level that provides a decrease in charge accumulation by utilizing electron energies in the range such that the secondary electron yield from said exposed surfaces is different from electron energies corresponding to previous electric charge accumulation.
A method for minimizing charging damage to a substrate in a plasma processing system comprising the steps:
- introducing an ionizable gas;
- forming a plasma from said ionizable gas;
- exposing said substrate to said plasma;
- and
- processing said substrate by coupling an RF power to said plasma processing system, wherein said RF power minimizes the accumulation of electric charge on one or more surfaces exposed to said plasma in said plasma processing system.
A method for minimizing charging damage to a substrate in a plasma processing system comprising the steps:
- identifying one or more exposed surfaces in said plasma processing system;
- disposing a secondary electron emitter on at least one of said one or more exposed surfaces, wherein said secondary electron emitter comprises a material having a secondary electron yield greater than unity;
- introducing an ionizable gas to said plasma processing system;
- forming a plasma from said ionizable gas;
- exposing a substrate to said plasma;
- and
- coupling said intermediate power to said plasma processing system to process said substrate, wherein said intermediate power corresponds to said secondary electron yield greater than unity for at least one of said one or more exposed surfaces.
A plasma processing system for minimizing charging damage to a substrate comprising:
- a plasma processing chamber to contain a plasma, said plasma processing chamber comprising one or more exposed surfaces in electrical contact with said plasma;
- at least one secondary electron emitter coupled to at least one of said one or more exposed surfaces, wherein said secondary electron emitter comprises a material having a secondary electron yield greater than unity.
Dependencies are inferred from the claim text.