Double shield for electron and ion beam columns
AssigneeCirrus Logic, Inc.
InventorSteven M. Czapski
Life of this patent
Estimating the term…
Abstract
The column surrounding an electron or ion beam is shielded with a second shield which is outside the column and isolated from the column, being connected to chassis ground at a location remote from the column. Also, wiring into the column is double shielded with the shields connected to ground at the end remote from the column and not at the column itself.
Claims22
Apparatus for double shielding an ion beam which is used to alter surfaces of semiconductor materials, comprising:
- a) a first shield enclosing and shielding an ion beam which is used to alters surfaces of semiconductor materials;
- and
- b) a second shield separate from said first shield, wherein said second shield is for said ion beam and surrounds and encompasses said first shield and said first and second shields form a double shield around said ion beam;
- and
- c) wherein said first shield is electrically isolated from said second shield and wherein said first and second shields are each separately grounded so that said second shield intercepts and prevents noise from reaching said first shield.
Apparatus for double shielding an ion beam which is used to alters surfaces of semiconductor materials, comprising:
- a) a first shield enclosing and shielding an ion beam which is used to alter surfaces of semiconductor materials;
- and
- b) a second shield separate from said first shield, wherein said second shield is for said ion beam and surrounds and encompasses said first shield and said first and second shields form a double shield around said ion beam;
- and
- c) wherein said first and second shields are separately grounded and wherein each column control cable, passing through said first and second shields, has column controlling conductors and wherein each column control cable further has a first conductor shield around each of the column controlling conductors and a second conductor shield around all of the column controlling conductors in which each pair of the first and second conductor shields form a double conductor shield for each of the respective column controlling conductors and wherein said first and second conductor shields are coupled to a ground different from said ground of said first shield.
Apparatus for double shielding an ion beam which is used to alter surfaces of semiconductor materials, comprising:
- a) a first shield enclosing and shielding an ion beam which is used to alter surfaces of semiconductor materials;
- and
- b) a second shield separate from said first shield, wherein said second shield is for said ion beam and surrounds and encompasses said first shield and said first and second shields form a double shield around said ion beam;
- and
- c) wherein said first shield is coupled to a chassis ground for said apparatus and said second shield is isolatedly coupled to a separate ground for at least another electrical device and said separate ground intercepts noise from said at least another electrical device from being reached at said first shield.
A metallic shield that surrounds a metallic column which shields an ion beam that alters surfaces of semiconductor materials, comprising:
- a metallic container that surrounds and is electrically isolated from a metallic column which shields an ion beam that alters surfaces of semiconductor materials, wherein said metallic container and said metallic column are each separately coupled to a ground potential and wherein said metallic container intercepts and prevents noise from reaching said metallic column and wherein said metallic container that surrounds said metallic column double shields said ion beam.
Method for double shielding an ion beam which is used to alter surfaces of semiconductor materials, comprising:
- a) enclosing and shielding, by a first shield, an ion beam which is used to alter surfaces of semiconductor materials;
- b) surrounding and encompassing, by a second shield separate from said first shield, said first shield wherein said first and second shields form a double shield around said ion beam;
- and
- c) electrically isolating said first shield from said second shield and separately grounding each of said first and second shields so that said second shield intercepts and prevents noise from reaching said first shield.
Method for double shielding an ion beam which is used to alter surfaces of semiconductor materials, comprising:
- a) enclosing and shielding, by a first shield, an ion beam which is used to alter surfaces of semiconductor materials;
- and
- b) surrounding and encompassing, by a second shield separate from said first shield, said first shield wherein said first and second shields form a double shield around said ion beam;
- and
- c) separately grounding said first and second shields and passing a column control cable through said first and second shields wherein said column control cable has column controlling conductors and further has a first conductor shield around each of the column controlling conductors and a second conductor shield around all of the column controlling conductors in which each pair of the first and second conductor shields form a double conductor shield for each of the respective column controlling conductors and wherein said first and second conductor shields are coupled to a ground different from said ground of said first shield.
Method for double shielding an ion beam which is used to alter surfaces of semiconductor materials, comprising:
- a) enclosing and shielding, by a first shield, an ion beam which is used to alter surfaces of semiconductor materials;
- b) surrounding and encompassing, by a second shield separate from said first shield, said first shield wherein said first and second shields form a double shield around said ion beam;
- and
- c) coupling said first shield to a chassis ground for said apparatus and isolatedly coupling said second shield to a separate ground for at least another electrical device and intercepting, by said separate ground, noise from said at least another electrical device from being reached by said first shield.
Dependencies are inferred from the claim text.