US4243866A — Method and apparatus for forming a variable size …

Claim 1

Independent Claim 216 words

In electron beam apparatus having a source of electrons for providing an electron beam adapted for generating integrated circuit patterns upon a target positioned in a target area toward which said electron beam is directed, electron beam forming means along the path from said source to said target area comprising: a first beam shaping member having a first spot shaping aperture formed therein, a second beam shaping member having a second spot shaping aperture formed therein; means for focusing the image of said first aperture in the plane of said second spot shaping aperture to thereby form a composite spot shape defined by said image and said second aperture, means for focusing the image of said composite spot in the plane of said target, means for focusing the image of said source in a plane between said source and said image of said first aperture, means for deflecting said electron beam, so as to deflect said image of said first aperture laterally with respect to said second aperture to thereby vary the shape and dimensions of said composite spot selectively to enable imaging of variable shapes upon said target, and means for locating the focused image of said source in a plane substantially perpendicular to said path and coincident with the virtual center of said deflection.

Claim 2

Dependent Claim 216 words

In electron beam apparatus having a source of electrons for providing an electron beam adapted for generating integrated circuit patterns upon a target positioned in a target area toward which said electron beam is directed, electron beam forming means along the path from said source to said target area comprising: a first beam shaping member having a first spot shaping aperture formed therein, a second beam shaping member having a second spot shaping aperture formed therein; means for focusing the image of said first aperture in the plane of said second spot shaping aperture to thereby form a composite spot shape defined by said image and said second aperture, means for focusing the image of said composite spot in the plane of said target, means for focusing the image of said source in a plane between said source and said image of said first aperture, means for deflecting said electron beam, so as to deflect said image of said first aperture laterally with respect to said second aperture to thereby vary the shape and dimensions of said composite spot selectively to enable imaging of variable shapes upon said target, and means for locating the focused image of said source in a plane substantially perpendicular to said path and coincident with the virtual center of said deflection.

Claim 3

Dependent Claim 16 words

The apparatus of claim 1 wherein said first and second apertures have the same rectangular shape.

Claim 4

Dependent Claim 21 words

The apparatus of claim 2 wherein said focused image of said first aperture has the same dimensions as said second aperture.

Claim 5

Dependent Claim 23 words

The apparatus of claim 1 wherein said deflection means are electrostatic deflection means positioned along said path between said first and second apertures.

Claim 6

Dependent Claim 42 words

The apparatus of claim 4 wherein said electrostatic deflection means comprise at least one pair of primary plates spaced from and facing eath other in a first lateral direction across said beam path and means for applying a voltage between said plates.

Claim 7

Dependent Claim 46 words

The apparatus of claim 1 wherein the image of said source is focused in a plane proximate to the center of said deflection means and said locating means including means for moving the virtual center of said electrostatic deflection toward coincidence with said source image plane.

Claim 8

Dependent Claim 82 words

The apparatus of claim 6 wherein said means for moving said center of deflection comprises: a pair of auxiliary plates spaced from and facing each other across the beam path so as to provide a deflection in the same direction as said primary plates at a position adjacent to but spaced from said primary plates, and means for applying a variable voltage between said auxiliary plates to thereby provide a resultant virtual center of deflection in coincidence with said source image plane.

Claim 9

Dependent Claim 44 words

The apparatus of claim 5 wherein said electrostatic deflection means comprise a second pair of primary plates spaced from and facing each other in a second lateral direction across the beam path and means for applying a voltage between said second pair of plates.

Claim 10

Dependent Claim 90 words

The apparatus of claim 8 wherein said locating means includes means for moving said center of deflection comprising: first and second pairs of auxiliary plates, respectively spaced from and facing each other so as to provide deflection in the same directions of said first and second pairs of primary plates at positions respectively adjacent to but spaced from said primary plates, and means for applying variable voltages between said respective pairs of auxiliary plates to thereby provide a resultant virtual center of deflection in coincidence with said source image plane.

Claim 11

Dependent Claim 98 words

The apparatus of claim 5 further including means for maintaining a constant current density of the image at said target area irrespective of the shape and dimensions of said composite spot comprising: a pair of auxiliary plates spaced from and facing each other across the beam path so as to provide deflection in the same direction as said primary plates at a position adjacent to but spaced from said primary plates, means for applying a variable voltage across said auxiliary plates, and means for varying said voltage between said auxiliary plates to thereby maintain a constant current density.

Claim 12

Dependent Claim 168 words

In a method for directing a beam of electrons along a path from an electron source against a target positioned within a target area for the purpose of generating integrated circuit patterns upon said target, the steps comprising: shaping said beam by directing said beam through a first spot shaping aperture, focusing the image of said first aperture in the plane of a second spot shaping aperture to thereby form a composite spot shape defined by said image and said second aperture, focusing the image of said source between said souce and said image of said first aperture, deflecting said image of said first aperture laterally with respect to said second aperture to thereby vary the shape and dimensions of said composite spot selectively to enable imaging of variable shapes upon said target, locating the focused image of said souce in a plane substantially perpendicular to said path and coincident with the virtual center of said deflection, and focusing the image of said composite spot upon said target.

Claim 13

Dependent Claim 168 words

In a method for directing a beam of electrons along a path from an electron source against a target positioned within a target area for the purpose of generating integrated circuit patterns upon said target, the steps comprising: shaping said beam by directing said beam through a first spot shaping aperture, focusing the image of said first aperture in the plane of a second spot shaping aperture to thereby form a composite spot shape defined by said image and said second aperture, focusing the image of said source between said souce and said image of said first aperture, deflecting said image of said first aperture laterally with respect to said second aperture to thereby vary the shape and dimensions of said composite spot selectively to enable imaging of variable shapes upon said target, locating the focused image of said souce in a plane substantially perpendicular to said path and coincident with the virtual center of said deflection, and focusing the image of said composite spot upon said target.

Claim 14

Dependent Claim 16 words

The method of claim 11 wherein said first and second apertures have the same rectangular shape.

Claim 15

Dependent Claim 21 words

The method of claim 12 wherein said focused image of said first aperture has the same dimensions as said second aperture.

Claim 16

Dependent Claim 36 words

The method of claim 13 wherein said first aperture image is deflected electrostatically in a lateral direction by applying a primary voltage across the path of the electron beam at a position before the second aperture.

Claim 17

Dependent Claim 32 words

The method of claim 14 including the further steps of focusing the image of said source and moving the virtual center of said electrostatic deflection and said source image plane toward coincidence.

Claim 18

Dependent Claim 41 words

The method of claim 15 wherein said virtual center of deflection and said source image plane are moved toward coincidence by applying an auxiliary voltage across said path so as to provide deflection in the same direction as said primary voltage.

Claim 19

Dependent Claim 36 words

The method of claim 16 wherein said auxiliary voltage is applied in the opposite sense to that of the primary voltage to thereby move the resultant center of deflection in one direction along said beam path.

Claim 20

Dependent Claim 37 words

The method of claim 17 wherein said auxiliary voltage is applied in the same sense as that of the primary voltage to thereby move the resultant center of deflection in an opposite direction along said beam path.

Claim 21

Dependent Claim 41 words

The method of claim 15 wherein an auxiliary voltage is applied across said path so as to provide a deflection in the same direction as said primary voltage to thereby maintain a constant current density of the beam at said target.

Claim 22

Dependent Claim 184 words

In an electron beam apparatus having electron beam forming means for varying the shape and dimensions of an electron beam adapted for generating integrated circuit patterns upon a target, wherein said apparatus includes a source of electrons for providing an electron beam along a path from the source to a target, a first beam shaping member having a first aperture formed therein, a second beam shaping member having a second aperture formed therein, means for focusing the image of the source in a plane between the source and the image of the first aperture, means for focusing the image of a composite spot formed by the first aperture and the second aperture in the plane of the target, and means for deflecting the electron beam so as to deflect the image of the first aperture laterally with respect to the second aperture to thereby vary the shape and dimensions of the composite spot selectively, the improvement comprising means for locating the focused image of the source in a plane substantially perpendicular to said beam path and coincident with the virtual center of said deflection.

Claim 23

Dependent Claim 184 words

In an electron beam apparatus having electron beam forming means for varying the shape and dimensions of an electron beam adapted for generating integrated circuit patterns upon a target, wherein said apparatus includes a source of electrons for providing an electron beam along a path from the source to a target, a first beam shaping member having a first aperture formed therein, a second beam shaping member having a second aperture formed therein, means for focusing the image of the source in a plane between the source and the image of the first aperture, means for focusing the image of a composite spot formed by the first aperture and the second aperture in the plane of the target, and means for deflecting the electron beam so as to deflect the image of the first aperture laterally with respect to the second aperture to thereby vary the shape and dimensions of the composite spot selectively, the improvement comprising means for locating the focused image of the source in a plane substantially perpendicular to said beam path and coincident with the virtual center of said deflection.

Claim 24

Dependent Claim 16 words

The apparatus of claim 20 wherein said first and second apertures have the same rectangular shape.

Claim 25

Dependent Claim 25 words

The apparatus of claim 20 wherein said aperture image deflection means are electrostatic deflection means positioned along said path between said first and second apertures.

Claim 26

Dependent Claim 42 words

The apparatus of claim 22 wherein said electrostatic deflection means comprise at least one pair of primary plates spaced from and facing each other in a first lateral direction across said beam path and means for applying a voltage between said plates.

Claim 27

Dependent Claim 44 words

The apparatus of claim 23 wherein the image of said source is focused in a plane proximate to the center of said deflection means and further including means for moving the virtual center of said electrostatic deflection and said source image plane toward coincidence.

Claim 28

Dependent Claim 82 words

The apparatus of claim 24 wherein said means for moving said center of deflection comprises a pair of auxiliary plates spaced from and facing each other across the beam path so as to provide a deflection in the same direction as said primary plate at a position adjacent to but spaced from said primary plate, and means for applying a variable voltage between said auxiliary plates to thereby provide a resultant virtual center of deflection in coincidence with said source image plane.

Claim 29

Dependent Claim 46 words

The apparatus of claim 23 or 25 wherein said electrostatic deflection means comprise a second pair of primary plates spaced from and facing each other in a second lateral direction across the beam path and means for applying a voltage between said second pair of plates.

Claim 30

Dependent Claim 87 words

The apparatus of claim 26 wherein said means for moving said center of deflection comprises first and second pairs of auxiliary plates, respectively spaced from and facing each other so as to provide deflection in the same directions of said first and second pairs of primary plates at positions respectively adjacent to but spaced from said primary plates, and means for applying variable voltages between said respective pairs of auxiliary plates to thereby provide a resultant virtual center of deflection in coincidence with said source image plane.

Claim 31

Dependent Claim 98 words

The apparatus of claim 23 further including means for maintaining a constant current density of the image at said target area irrespective of the shape and dimensions of said composite spot comprising: a pair of auxiliary plates spaced from and facing each other across the beam path so as to provide deflection in the same direction as said primary plates at a position adjacent to but spaced from said primary plates, means for applying a variable voltage across said auxiliary plates, and means for varying said voltage between said auxiliary plates to thereby maintain a constant current density.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1984-01-06	1984-07-07	1985-01-06	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1988-01-06	1988-07-07	1989-01-06	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1992-01-06	1992-07-07	1993-01-06	$7700.00	Window Closed / Lapsed

Method and apparatus for forming a variable size electron beam

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