Thermally stable magnetic deflection assembly and method of making same
AssigneeEtec Systems, Inc.
InventorLydia J. Young
Life of this patent
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Abstract
A thermally stable magnetic deflection assembly for use in an electron or particle beam machine with several separately potted magnetic coils spaced apart and arranged in a particular vertical position on a central pipe. Non metallic, low coefficient of thermal expansion, highly thermally conductive materials are used throughout and means are provided for maintaining the entire assembly at a desired temperature. Also disclosed is a method of making a thermally stable magnetic deflection assembly.
Claims11
For a beam column of a lithography machine, a thermally stable magnetic deflection assembly comprising,
- a plurality of magnetic coils each formed of conductors wound on a toroidal coil form of non-metallic thermally stable material,
- each coil being coated with a highly thermally conductive potting material,
- a hollow pipe of non-metallic thermally stable material,
- said coils being stacked on said pipe,
- means for vertically spacing each coil from each other, and
- means for maintaining said assembly at a selected temperature.
In a beam column of a lithography machine having a beam directed through said beam column and onto a substrate and having a magnetic deflection assembly for positioning the beam within a field of a selected size on said substrate, the improvement in said magnetic deflection assembly such that said assembly is thermally stable comprising,
- a plurality of magnetic coils for deflecting said beam when a current is applied thereto each of said coils being formed of conductors wound on a toroidal coil form of non-metallic thermally stable material,
- each coil being coated with a highly thermally conductive potting material,
- a hollow pipe of non-metallic thermally stable material through which said beam is directed,
- said coils being stacked on said pipe,
- means for vertically spacing each coil from each other, and
- means for maintaining said assembly at a selected temperature.
A method of forming a magnetic deflection assembly for use in a lithography machine comprising the steps of:
- winding a plurality of conductors around a plurality of coil forms of non-metallic thermally stable material,
- vacuum potting each of said coils individually with a non-metallic high thermally conductive potting material,
- stacking said potted coils on a pipe of a non-metallic thermally stable material in a snug fit therebetween,
- spacing each of said coils from each other by a predetermined amount, and
- enclosing said coils with a non-metallic shroud having passageways for the circulation of fluid coolant around said coils to maintain said assembly at a desired temperature during operation of said assembly as a magnetic deflection assembly in the beam column of a lithography machine.
Dependencies are inferred from the claim text.