Back to results
US 5,317,161 AGranted
Ion source
AssigneeIMS Ionen Mikrofabrikations Systeme Gesellschaft m.b.H.
InventorsAlfred Chalupka, Gertraud Lammer, Gerhard Stengl, Peter Wolf, Johannes Fegerl
Life of this patent
Estimating the term…
Abstract
In addition to the three electrodes of a unipotential lens following a plasma chamber, an ion source for ion beam lithography or ion beam semiconductor or the like has a fourth electrode which is at the same potential as the second electrode and at a potential lower than the potential of the first and third electrodes The result is improved resolution.
Claims16
A duoplasmatron type ion source for use with an ion-optic imaging system, comprising:
- a plasma chamber having an outlet from which ions generated in said plasma chamber emerge;
- and
- an electrode assembly aligned with said outlet and traversed by ions supplied to said ion-optic imaging system, said electrode assembly comprising:
- first, second, third and fourth axially spaced electrodes arrayed in succession along a path of said ions through said assembly, having axially aligned windows traversed by said ions and centered on a common axis,
- means for applying approximately the same potentials to said second and fourth electrodes, and
- means for applying to said first and third electrodes substantially the same potentials at a level higher than the potentials at said second and fourth electrodes so that the ions traversing said assembly are accelerated to a final energy by a potential difference between said first and fourth electrodes, at said potentials of said electrodes, the spacing between two neighboring electrodes being is selected to produce an electrical field strength therebetween in a region of said axis which exceeds 5 megavolt/meter.
3 more elements
A duoplasmatron type ion source for use with an ion-optic imaging system, comprising:
- a plasma chamber having an outlet from which ions generated in said plasma chamber emerge;
- and
- an electrode assembly aligned with said outlet and traversed by ions supplied to said ion-optic imaging system, said electrode assembly comprising:
- first, second, third and fourth axially spaced electrodes arrayed in succession along a path of said ions through said assembly, having axially aligned windows traversed by said ions and centered on a common axis,
- means for applying approximately the same potentials to said second and fourth electrodes, and
- means for applying to said first and third electrodes substantially the same potentials at a level higher than the potentials at said second and fourth electrodes so that the ions traversing said assembly are accelerated to a final energy by a potential difference between said first and fourth electrodes, said first and third electrodes being at exactly the same potentials and said second and fourth electrodes being at exactly the same potentials, said first electrode being at a positive potential and the fourth electrode being at ground potential.
3 more elements
Dependencies are inferred from the claim text.