Patent EP1091252A2 successfully refreshed from Google Patents.
EP1091252A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Lithographic method and apparatus
Assignee: ASML Netherlands BV
•
Filing: 2000-09-28
•
Granted: —
•
Expires: 2020-09-28
Abstract
Abstract A method of imaging a pattern in a microlithographic exposure apparatus comprises performing two exposures, each with a different mask, the superposition of the images defined by the two masks produces the complete circuit pattern. A dipolar illumination mode is used for each exposure, the dipoles of the two exposures being mutually perpendicular. The dipolar illumination mode of the first exposure is used to image mask features parallel to a first direction, and the dipolar illumination mode of the second exposure is used to image mask features perpendicular to the first direction.
Inventors
- 👤 Jozef Finders
- 👤 Johannes Baselmans
- 👤 Donis Flagello
- 👤 Igor Bouchoms
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 22:42
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70425; G03F1/00; G03F1/68; G03F1/70; G03F7/70058; G03F7/70091; G03F7/701; G03F7/70125
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
60 words
A method of imaging a pattern onto a substrate provided with a layer of
energy-sensitive material, comprising the steps of: performing a first exposure to image partly said pattern; performing a second exposure to image partly said pattern, wherein at least one of said first and second exposures is performed using an
illumination mode having a substantially dipolar intensity distribution.
Claim 2
Dependent Claim
35 words
A method according to claim 1, wherein the other of said first and second
exposures is performed using an illumination mode having an intensity distribution which is
substantially one of: dipolar, quadrupolar, annular and disc-like.
Claim 3
Dependent Claim
27 words
A method according to claim 1 or 2, wherein a different mask is used to define
the image formed by each of said first and second exposures.
Claim 4
Dependent Claim
19 words
A method according to claim 3, further comprising the step of exchanging
masks between said first and second exposures.
Claim 5
Dependent Claim
58 words
A method according to claim 1 or 2, wherein a mask having at least two sub-patterns
is used for the first and second exposures, a first of the said sub-patterns being used
to define the image formed by the first exposure and the second of the sub-patterns being
used to define the image formed by the second exposure.
Claim 6
Independent Claim
43 words
A method according to any one of the preceding claims, wherein the or each
dipolar illumination mode is used to image linear features of the pattern oriented substantially
perpendicular to the axis joining the respective two poles of the or each dipole mode.
Claim 7
Dependent Claim
46 words
A method according to claim 6, wherein the respective mask or mask sub-pattern
used with the or each dipolar illumination mode exposure substantially defines only
features of the pattern oriented substantially perpendicularly to the axis joining the respective
two poles of the or each dipole mode.
Claim 8
Independent Claim
48 words
A method according to any one of the preceding claims, wherein the or each
dipolar illumination mode intensity distribution comprises two relatively intense poles and
further comprises one or more of: a relatively weak central pole; two relatively weak further
poles; and a general relatively weak background intensity.
Claim 9
Independent Claim
33 words
A method according to any one of the preceding claims, further comprising the
step of: changing at least one of the pole radial position, size and intensity between said first
and second exposures.
Claim 10
Independent Claim
38 words
A method according to any one of the preceding claims, wherein said first and
second exposures are both performed using dipolar illumination modes and wherein the axes
of the two dipolar modes are substantially perpendicular to each other.
Claim 11
Independent Claim
34 words
A method according to any one of the preceding claims, wherein the or each of
the exposures performed using an illumination mode having a substantially dipolar intensity
distribution, is performed using polarized electromagnetic radiation.
Claim 12
Dependent Claim
13 words
A method according to claim 11, wherein the polarized radiation is linearly
polarized.
Claim 13
Dependent Claim
38 words
A method according to claim 12, wherein the radiation is thus polarized so as
to have an electric field component oriented substantially perpendicular to the axis joining the
respective two poles of the or each dipole intensity distribution.
Claim 14
Independent Claim
42 words
A method according to any of the claims 1-13, wherein, between the first and
second exposures, the focus of the pattern on the substrate is adjusted, thereby to ensure that
both the first and second exposures are performed at substantially optimum focus.
Claim 15
Independent Claim
34 words
A method according to any of the claims 1-14, wherein the or each of the
exposures using an illumination mode having a substantially dipolar intensity distribution, is
performed using an attenuated phase shift mask.
Claim 16
Dependent Claim
48 words
A method according to claim 15, wherein the attenuation is thus chosen so as
to balance the energy of radiation of the zeroth -and first-order diffracted beams, as they are
emerging from said pattern and captured by a projection system used to image the patterns on
the substrate.
Claim 17
Independent Claim
56 words
A device manufacturing method comprising the steps of: providing a substrate which is at least partially covered by a layer of energy-sensitive
material; providing at least one mask for defining a pattern; and imaging at least part of said mask pattern onto said substrate using a method
according to any one of claims 1 to 16.
Claim 18
Independent Claim
16 words
A device manufactured in accordance with the method of any one of claims 1
to 17.
Claim 19
Independent Claim
91 words
An apparatus for imaging a pattern onto a substrate provided with a layer of
energy sensitive material, said apparatus comprising: an illumination system for defining first and second illumination modes; a projection system for imaging parts of said pattern defined by a mask on said
substrate; and a changer for changing between first and second masks; wherein at least one of said first and second illumination modes is dipolar and
wherein said apparatus is arranged to image said pattern by two exposures using respective
first and second illumination modes and masks.
Claim 20
Independent Claim
120 words
An apparatus for imaging a pattern onto a substrate provided with a layer of
energy sensitive material, said apparatus comprising: an illumination system for defining first and second illumination modes; a projection system for imaging parts of said pattern defined by a mask on said
substrate; and means for moving the mask with respect to the projection system, so as to distinctly
position first and second mask sub-patterns, located at different positions on the mask, in the
radiation beam emerging from the illumination system; wherein at least one of said first and second illumination modes is dipolar and
wherein said apparatus is arranged to image said pattern by two exposures using respective
first and second illumination modes and mask sub-patterns.
Claim 21
Dependent Claim
27 words
An apparatus according to claim 19 or 20, wherein said illumination system
comprises one or more diffractive optical elements for defining said first and second
illumination modes.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.