US 5,350,924 AGranted

Ion-optical imaging system

AssigneeIMS Ionen Mikrofabrikations Systems Gesellschaft mbH

InventorsGerhard Stengl, Alfred Chalupka

Life of this patent

Estimating the term…

Loading patent…

Abstract

A system for ion-beam imaging of a structure of a mask on a wafer has a two-lens set between the mask and the wafer which is one of the following combinations: (a) two accelerating Einzel lenses; (b) an accelerating immersion lens and a decelerating immersion lens wherein the accelerating immersion lens is the first collecting lens following the mask; (c) an accelerating immersion lens and a decelerating asymmetric Einzel lens wherein the accelerating immersion lens is the first collecting lens following the mask; (d) an accelerating asymmetric Einzel lens and a decelerating immersion lens wherein the accelerating asymmetric Einzel lens is the first collecting lens following the mask; and (e) an accelerating asymmetric Einzel lens and a decelerating asymmetric Einzel lens wherein the accelerating asymmetric Einzel lens is the first collecting lens following the mask.

Claims12

Dependent claims

An ion-optical imaging system, comprising:

a mask having a structure to be imaged upon a wafer and including at least one opening;
means for supporting the wafer upon which said structure is to be imaged at a distance from said mask along an optical axis;
and
a lens system disposed between said mask and said wafer and essentially consisting of a set of two collecting lenses including a first collecting lens following said mask along said axis in a direction of ion beam travel toward said wafer, and a second collecting lens spaced from the first collecting lens along said axis in said direction,
said mask being disposed approximately in an object-side focal plane of the first collecting lens,
the wafer being positioned in a vicinity of an image-side focal plane of the second collecting lens following the mask, and
the set is constituted of one of the following lens-type sets:
(a) two accelerating Einzel lenses;
(b) an accelerating immersion lens and a decelerating immersion lens wherein the accelerating immersion lens is the first collecting lens following the mask;
(c) an accelerating immersion lens and a decelerating asymmetric Einzel lens wherein the accelerating immersion lens is the first collecting lens following the mask;
(d) an accelerating asymmetric Einzel lens and a decelerating immersion lens wherein the accelerating asymmetric Einzel lens is the first collecting lens following the mask;
and
(e) an accelerating asymmetric Einzel lens and a decelerating asymmetric Einzel lens wherein the accelerating asymmetric Einzel lens is the first collecting lens following the mask.

10 more elements

An ion-optical imaging system, comprising:

a mask having a structure to be imaged upon a wafer and including at least one opening;
means for supporting the wafer upon which said structure is to be imaged at a distance from said mask along an optical axis;
a lens system disposed between said mask and said wafer and essentially consisting of a set of two collecting lenses including a first collecting lens following said mask along said axis in a direction of ion beam travel toward said wafer, and a second collecting lens spaced from the first collecting lens along said axis in said direction,
said mask being disposed approximately in an object-side focal plane of the first collecting lens,
the wafer being positioned in a vicinity of an image-side focal plane of the second collecting lens following the mask, and
the set is constituted of one of the following lens-type sets:
(a) two accelerating Einzel lenses;
(b) an accelerating immersion lens and a decelerating immersion lens wherein the accelerating immersion lens is the first collecting lens following the mask;
(c) an accelerating immersion lens and a decelerating asymmetric Einzel lens wherein the accelerating immersion lens is the first collecting lens following the mask;
(d) an accelerating asymmetric Einzel lens and a decelerating immersion lens wherein the accelerating asymmetric Einzel lens is the first collecting lens following the mask;
and
(e) an accelerating asymmetric Einzel lens and a decelerating asymmetric Einzel lens wherein the accelerating asymmetric Einzel lens is the first collecting lens following the mask, a crossover of the first collecting lens following the mask lying in an object-side focal plane of the second collecting lens following the mask;
an ion source disposed along said axis ahead of said mask for generating an ion beam;
a mass separator formed as an ExB filter between said ion source and said mask along said axis;
a condensing lens ahead of said mass separator along said axis and preferably being an Einzel lens;
and
an illumination lens following said mass separator along said axis and being an accelerating Einzel lens.

14 more elements

An ion-optical imaging system, comprising:

a mask having a structure to be imaged upon a wafer and including at least one opening;
means for supporting the wafer upon which said structure is to be imaged at a distance from said mask along an optical axis;
a lens system disposed between said mask and said wafer and essentially consisting of a set of two collecting lenses including a first collecting lens following said mask along said axis in a direction of ion beam travel toward said wafer, and a second collecting lens spaced from the first collecting lens along said axis in said direction,
said mask being disposed approximately in an object-side focal plane of the first collecting lens
the wafer being positioned in a vicinity of an image-side focal plane of the second collecting lens following the mask, and
the set is constituted of one of the following lens-type sets:
(a) two accelerating Einzel lenses;
(b) an accelerating immersion lens and a decelerating immersion lens wherein the accelerating immersion lens is the first collecting lens following the mask;
(c) an accelerating immersion lens and a decelerating asymmetric Einzel lens wherein the accelerating immersion lens is the first collecting lens following the mask;
(d) an accelerating asymmetric Einzel lens and a decelerating immersion lens wherein the accelerating asymmetric Einzel lens is the first collecting lens following the mask;
and
(e) an accelerating asymmetric Einzel lens and a decelerating asymmetric Einzel lens wherein the accelerating asymmetric Einzel lens is the first collecting lens following the mask, a crossover of the first collecting lens following the mask lying in an object-side focal plane of the second collecting lens following the mask;
an ion source disposed along said axis ahead of said mask for generating an ion beam;
a mass separator formed as an ExB filter between said ion source and said mask along said axis;
a condensing lens ahead of said mass separator along said axis and preferably being an Einzel lens;
and
an illumination lens following said mass separator along said axis and being a decelerating Einzel lens.

14 more elements

An ion-optical imaging system, comprising:

a mask having a structure to be imaged upon a wafer and including at least one opening;
means for supporting the wafer upon which said structure is to be imaged at a distance from said mask along an optical axis;
a lens system disposed between said mask and said wafer and essentially consisting of a set of two collecting lenses including a first collecting lens following said mask along said axis in a direction of ion beam travel toward said wafer, and a second collecting lens spaced from the first collecting lens along said axis in said direction,
said mask being disposed approximately in an object-side focal plane of the first collecting lens,
the wafer being positioned in a vicinity of an image-side focal plane of the second collecting lens following the mask, and
the set is constituted of one of the following lens-type sets:
(a) two accelerating Einzel lenses;
(b) an accelerating immersion lens and a decelerating immersion lens wherein the accelerating immersion lens is the first collecting lens following the mask;
(c) an accelerating immersion lens and a decelerating asymmetric Einzel lens wherein the accelerating immersion lens is the first collecting lens following the mask;
(d) an accelerating asymmetric Einzel lens and a decelerating immersion lens wherein the accelerating asymmetric Einzel lens is the first collecting lens following the mask;
and
(e) an accelerating asymmetric Einzel lens and a decelerating asymmetric Einzel lens wherein the accelerating asymmetric Einzel lens is the first collecting lens following the mask, a crossover of the first collecting lens following the mask lying in an object-side focal plane of the second collecting lens following the mask;
an ion source disposed along said axis ahead of said mask for generating an ion beam;
a mass separator formed as an ExB filter between said ion source and said mask along said axis;
a condensing lens ahead of said mass separator along said axis and preferably being an Einzel lens;
and
an illumination lens following said mass separator along said axis and being at least one solenoid.

14 more elements

Dependencies are inferred from the claim text.