United States Patent and Trademark Office
WIPO Revision Working Group
Project: A023
Date: October 15, 2010
Photo-masks and screens (T036)
Title – G03F 1/00
Originals for photomechanical production of textured or patterned
surfaces, e.g., masks, photo-masks, reticles; Mask blanks or pellicles
therefor; Containers specially adapted therefor; Preparation thereof
Definition statement
This group covers:
Patterned radiation modifying products that are chemically defined and have been
patterned to modify radiation during imaging (e.g., masks, photomasks, reticles),
preparation of such patterned radiation modifying products, similar or like products
that function as mask blanks or specialized substrates, per se, for preparing such
patterned radiation modifying products, processes of preparing such mask blanks or
specialized substrates, per se (when not provided for elsewhere), pellicles, per se or
pellicles in combination with patterned radiation modifying products, processes of
preparing such pellicles (when not provided for elsewhere), containers that are specially
adapted therefor, or processes of preparing the same (when not provided for elsewhere).
Informative references
Attention is drawn to the following places, which may be of interest for search:
Electrography; electrophotography
G03G
Photomechanical process; apparatus; photosensitive material,
e.g., photoresist, in general
G03F 7/00
Use of photoresist structures for special production processes,
e.g.:

Producing decorative effects

Manufacture or treatment of semiconductor or solid
state devices or parts thereof
B44C
H01L 21/00
Printed circuits; details of electric apparatus; manufacture of
electrical components, in general
H05K
Holographic processes or apparatus
G03H
Special rules of classification within this group
In this main group, at each hierarchical level, in the absence of an indication to the contrary,
classification is made in the first appropriate place.
Title – G03F 1/20
Masks or mask blanks for imaging by charged particle beam (CPB)
radiation, e.g., by electron beam; Preparation thereof
Definition statement
This subgroup covers:
Subject matter of main group G03F 1/00 in which the radiation modifying products are
either patterned masks for imaging by charged particle beam (CPB) radiation (e.g., by
electron beam), mask blanks therefor, or specialized substrates for preparing such
patterned masks; and the processes of preparing are directed to preparation of such
patterned masks for imaging by charged particle beam (CPB) radiation, preparation of
mask blanks therefor, or preparation of specialized substrates therefor.
Title – G03F 1/22
Masks or mask blanks for imaging by radiation of 100nm or shorter
wavelength, e.g., X-ray masks, Extreme ultraviolet (EUV) masks;
Preparation thereof
Definition statement
This subgroup covers:
Subject matter of main group G03F 1/00 in which the radiation modifying products are
either patterned masks for imaging by radiation of 100 nanometers or shorter
wavelength (e.g., X-ray masks, extreme ultraviolet (EUV) masks), mask blanks therefor,
or specialized substrates for preparing such patterned masks; and the processes of
preparing are directed to preparation of such patterned masks for imaging by radiation
of 100 nanometers or shorter wavelength (e.g., X-ray masks, extreme ultraviolet (EUV)
masks), preparation of mask blanks therefor, or preparation of specialized substrates
therefor.
Title – G03F 1/26
Phase shift masks (PSM’s); PSM blanks therefor; Preparation thereof
Definition statement
This subgroup covers:
Subject matter of main group G03F 1/00 in which the radiation modifying products are
either patterned phase shift masks (PSM’s), PSM blanks therefor, or specialized
substrates for preparing such patterned PSM’s; and the processes of preparing are
directed to preparation of such patterned PSM’s, preparation of PSM blanks therefor,
or preparation of specialized substrates therefor.
(1) Note. In this subgroup, the phase shift mask (PSM) has a phase shift (PS)
transmissive or reflective region that provides a different effective optical path
length for illumination exiting the PS region than that of another (usually
adjacent non-PS) region, so that exiting illumination from these separate regions
are at different phases from each other. When the phase difference between
adjacent PS and non-PS regions is 180 degrees, destructive interference is
maximized for the exiting illumination between these regions, causing minimum
combined diffracted light intensity, which results in a darkened projected light
intensity that improves resolution when exposing a photosensitive layer (such as a
photoresist).
(2) Note. For a transmissive PSM, the phase shift (PS) region is usually produced
by selective addition of a transparent PS layer that increases the effective
thickness of a transmissive substrate or by selective etching to create a recess that
decreases the thickness of the transmissive substrate, each of which provides
exiting illumination that differs in phase from illumination exiting another
unchanged region of the transmissive substrate. However, the difference in
phase at the phase shifting region can also be produced by selective doping or
implantation of particular ions into the transmissive substrate to selectively
change the refractive index or other optical characteristic of the transparent
substrate, altering the passage of illuminated light exiting from the phase shifting
region relative to light exiting from another (non-PS) region of the transmissive
substrate for the PSM.
Title – G03F 1/28
Three or more diverse phases from the same PSM; Preparation thereof
Definition statement
This subgroup covers:
Subject matter of subgroup G03F 1/26 in which the phase shift mask (PSM) has three
(3) or more different transmissive or reflective portions thereon that provide three (3) or
more diverse phases of exiting illumination (e.g., tri-tone PSM for 0°, 90°, and 180°
phases); and in which the process of preparing is directed to preparation of such a
patterned PSM.
Title – G03F 1/29
Rim PSM or outrigger PSM; Preparation thereof
Definition statement
This subgroup covers:
Subject matter of subgroup G03F 1/26 in which the phase shift mask (PSM) has an
absorber region with an adjacent clear narrow ridge that produces phase shifted exiting
illumination (180 degrees out of phase) with respect to non-phase shifted illumination
exiting a non-phase shifted clear region of a transparent substrate, where the absorber
region represents a pattern to be reproduced (rim PSM or outrigger PSM); and in
which the process of preparing is directed to preparation of such a rim PSM or an
outrigger PSM.
Title – G03F 1/30
Alternating PSM, e.g. Levenson-Shibuya PSM; Preparation thereof
Definition statement
This subgroup covers:
Subject matter of subgroup G03F 1/26 in which the phase shift mask (PSM) has
alternating diverse phase clear regions separated by an absorber region that represents
a pattern to be reproduced, where the absorber region is usually in the form of absorber
lines separated by alternating phase shift (PS) spaces and non-phase shift (non-PS)
spaces in repeating sequence across a major surface of the PSM (e.g., Levenson-Shibuya
PSM, etc.); and in which the process of preparing is directed to preparation of such an
alternating PSM (alt-PSM).
Title – G03F 1/32
Attenuating phase shift mask (att-PSM), e.g., PSM having semi-transparent
phase shift portion, halftone PSM; Preparation thereof
Definition statement
This subgroup covers:
Subject matter of subgroup G03F 1/26 in which the phase shift mask (PSM) has an
attenuating region that produces phase shifted exiting illumination at a different phase
from that produced by a non-attenuating clear region of the attenuating PSM (e.g., PSM
having semi-transparent phase shift portion, halftone PSM); and in which the process of
preparing is directed to preparation of such an attenuating PSM (att-PSM).
(1) Note. In this attenuating PSM (att-PSM, halftone PSM), the attenuating
or halftone region is partially transmissive and provides a phase shift (PS) in
exiting illumination. The degree of PS and the transmissiveness of the att-PS
region depends on the material and thickness of the att-PS region, as well as
depending on the wavelength of the illumination. Such an att-PS region or a
halftone PS region can be formed by adding an appropriate material at a
suitable thickness, reducing the thickness of a previously formed layer
(whether a supporting substrate of the att-PSM or an additional layer
thereon), or other post-treatment of an att-PSM portion (such as selective
doping or ion implantation).
(2) Note. An att-PS region can be created by sufficiently reducing the thickness
of a normally opaque absorber layer material, such as a thin layer of chromium
(Cr) often called “leaky chrome”.
Title – G03F 1/34
Phase-edge PSM, e.g. chromeless PSM; Preparation thereof
Definition statement
This subgroup covers:
Subject matter of subgroup G03F 1/26 in which the phase shift mask (PSM) has at least
two clear regions directly adjacent to each other that produce different phases (usually
180 degrees apart) to create a phase edge between these diverse clear regions in
corresponding portions of exiting illumination, where the phase edge represents a
pattern to be reproduced (e.g., chromeless PSM, etc.); and in which the process of
preparing is directed to preparation of such a phase edge PSM.
Note. In this subgroup, such a phase edge PSM can be without any opaque
region (as a chromeless PSM). Alternatively, the phase edge PSM is permitted to
include an opaque region or an absorber region, such as at the peripheral border
of this phase edge PSM to avoid unwanted artifacts that might otherwise be
produced in a common photoresist layer by step-and-repeat exposures from this
phase edge PSM. However, this phase edge PSM must still have at least one
unobstructed phase edge between two directly adjacent clear regions that
produce exiting illumination having different phases (e.g., at 0° and 180°, etc.),
where the phase edge represents a pattern to be reproduced, as described above.
Title – G03F 1/36
Masks having proximity correction features; Preparation thereof, e.g.
optical proximity correction [OPC] design processes
Definition statement
This subgroup covers:
Subject matter of main group G03F 1/00 in which the patterned radiation modifying
products are masks, where the mask has a pattern that includes a proximity correction
feature or a changed dimension of a printing feature for improving a resulting printed
pattern formed thereby (e.g., enhancing sub-resolution sized patterns, reducing sidelobe formation between closely spaced patterns); and in which the processes of
preparing are directed to preparation of such masks having proximity correction
features (e.g., optical proximity correction [OPC] design processes).
(1) Note. Proximity correction addresses problems resulting from the
miniaturization of patterns for radiation modifying masks, which typically
results in degradation of the pattern, with the degradation not being uniform
between sorts of pattern such as, for example, a line-and-space pattern, an
isolated pattern, etc.
(2) Note. The proximity correction features can be sub-resolution patterns (e.g.
serifs, assist bars) or modified patterns (e.g. biased) to compensate for optical
proximity effects in a basic layout of a mask pattern. Alternatively, the proximity
correction features can be dummy patterns, which are placed in a vacant region
of a mask pattern to reduce inhomogeneous processing due to proximity effects.
Informative references
Attention is drawn to the following places, which may be of interest for search:
Adapting basic layout or design of a mask to a lithographic
process requirement for preparation of masks without proximity
G03F 1/70
correction features
Computer-aided design in general
G06F 17/50
Title – G03F 1/38
Masks having auxiliary features, e.g., marks for alignment or testing,
special coatings; Preparation thereof
Definition statement
This subgroup covers:
Subject matter of main group G03F 1/00 in which the patterned radiation modifying
products are masks having auxiliary features, where the mask possesses some structure
in addition to that used for imaging and this structure is used for subsidiary purposes;
and in which the processes of preparing are directed to preparation of such masks
having auxiliary features.
Note. For example, the subsidiary purposes may be for alignment of the mask
within an exposure apparatus, for testing of the mask, for protecting the mask, or
for improving an image obtained from the mask.
Title – G03F 1/50
Mask blanks; Preparation thereof
Definition statement
This subgroup covers:
Subject matter of main group G03F 1/00 in which the radiation modifying products are
mask blanks for producing patterned masks; and in which the processes of preparing
are directed to preparation of such mask blanks.
Title – G03F 1/52
Reflectors
Definition statement
This subgroup covers:
Subject matter of main group G03F 1/00 in which the radiation modifying products
have a reflector that functions as a mirror to deflect incident radiation.
Note. The reflector can be a particular material that is chemically defined.
Alternatively, the specified reflector can have a specific shape, a particular
thickness, or a given internal microstructure (such as a reflector that was
subjected to a particular heat treatment to relieve internal stress).
Title – G03F 1/54
Absorbers, e.g. of opaque material
Definition statement
This subgroup covers:
Subject matter of main group G03F 1/00 in which the radiation modifying products
have an absorber (e.g., of opaque material) which functions to absorb incident radiation.
(1) Note. The absorber can be a particular opaque material that is chemically
defined (e.g., tantalum (Ta), gold (Au), chromium (Cr), carbon (C), molybdenum
silicide (MoSi)). Alternatively, the absorber can have a specific pattern (e.g., an
unresolvable grid pattern leading to a grey tone mask, a gradient mask), a
particular thickness (e.g., making the absorber region semi-transparent to
provide only 20% transmittance for incident radiation at a target wavelength for
imaging), or a given internal structure (e.g., multilayer absorber, ion implanted
opaque layer to change an optical property for absorbing more incident
radiation).
(2) Note. Excluded from this subgroup are attenuating phase shift masks (PSMs)
having PS regions created by sufficiently reducing the thickness of a normally
opaque absorber layer material, such as a thin layer of chromium (Cr) often
called “leaky chrome”.
Title – G03F 1/60
Substrates
Definition statement
This subgroup covers:
Subject matter of main group G03F 1/00 in which the radiation modifying products or
similar products have a substrate defined by a particular material, a given structure, or
a stated property, making the substrate especially suited (e.g., in a patterned mask, in a
mask blank therefor) for use in radiation imaging.
Informative References
Attention is drawn to the following places, which may be of interest for search:
Layered products characterized by the non-homogeneity or
physical structure of a layer
B32B 5/00
Title – G03F 1/62
Pellicles, e.g. pellicle assembly having membrane on support frame;
Preparation thereof
Definition statement
This subgroup covers:
Subject matter of main group G03F 1/00 in which the pellicles, per se, or the pellicles in
combination with radiation modifying products, provide protection for a patterned
mask by excluding foreign matter (e.g., solid particles of dust) that would otherwise
degrade proper imaging from the patterned mask (e.g., pellicle assembly having
membrane on support frame).
Note. In this subgroup, the pellicle often includes a thin transparent layer (such
as a transparent flexible membrane) attached to a rigid frame to hold the thin
transparent layer at a specified distance away from the mask pattern so that
foreign matter collecting on the outside of the pellicle will not be in the range of
focus during imaging, in order to avoid degradation of the resulting imaged
pattern produced from the mask. Alternatively, the pellicle can be a hard selfsupporting layer, having a specified thickness and transparency, that is formed
on the patterned mask. In either case, the pellicle still protects the mask, to
which the pellicle is attached, from dust adhering on the mask pattern that would
otherwise occur during imaging of the mask without any benefit of the pellicle.
Title – G03F 1/64
having special frames, e.g. structure or material, including bonding means
therefor
Definition statement
This subgroup covers:
Subject matter of subgroup G03F 1/62 in which the pellicles have special frames (e.g.
structure or material), including bonding means for the pellicle frame, which establishes
a bond between the frame and a pellicle membrane or between a frame and a substrate
of a radiation modifying product.
Note. In this subgroup, the bonding means often includes an adhesive layer.
Alternatively, the bonding means can include a structure that provides a physical
attachment.
Title – G03F 1/66
Containers specially adapted for masks, mask blanks, or pellicles;
Preparation thereof
Definition statement
This subgroup covers:
Subject matter of main group G03F 1/00 in which the containers are specially adapted
for holding, protecting, or transporting of masks, mask blanks, or pellicles as defined
therein; and the processes of preparing such containers (when not provided for
elsewhere).
Title – G03F 1/68
Preparation processes
Definition statement
This subgroup covers:
Subject matter of main group G03F 1/00 in which the preparation processes for
preparing radiation modifying products and similar or like products include particular
preparation steps, specific manufacturing methods, or given design steps for preparing
these products, but which preparation processes are not specifically provided for in the
previous subgroups.
Title – G03F 1/70
Adapting basic layout or design of mask to lithographic process
requirement, e.g. second iteration correction of mask pattern for imaging
Definition statement
This subgroup covers:
Subject matter of subgroup G03F 1/68 in which the preparation processes are for
adapting basic layout of patterned radiation modifying products to a lithographic
process requirement, which include methods for adapting, modifying or correcting of
basic patterns for a radiation mask used for photomechanical production of textured or
patterned surfaces (e.g. second iteration correction of mask pattern for imaging).
Informative references
Attention is drawn to the following places, which may be of interest for search:
Proximity correction layout or design processes for preparation
of masks with proximity correction features, e.g. OPC features
G03F 1/36
Computer-aided design in general
G06F 17/50
Title – G03F 1/72
Repair or correction of mask defects
Definition statement
This subgroup covers:
Subject matter of subgroup G03F 1/68 in which the preparation processes for preparing
patterned radiation modifying products include methods for repair or correction of
mask defects. e.g., by removing excess part defects or filling in missing part defects.
Title – G03F 1/76
Patterning of masks by imaging
Definition statement
This subgroup covers:
Subject matter of subgroup G03F 1/68 in which the processes for preparing patterned
radiation modifying products include patterning of masks by imaging.
Note. Typically, this imaging to pattern the mask is accomplished by selectively
exposing and developing a photosensitive layer (e.g., a photoresist layer on a
mask blank) for defining a pattern therein that is used to form the resulting
patterned mask.
Title – G03F 1/80
Etching
Definition statement
This subgroup covers:
Subject matter of subgroup G03F 1/68 in which the processes for preparing patterned
radiation modifying products include an etching step to selectively remove material
from a mask or a mask blank.
Informative References
Attention is drawn to the following places, which may be of interest for search:
Etching metallic material by chemical means
Title – G03F 1/82
Auxiliary processes, e.g. cleaning or inspecting
C23F 1/00
Definition statement
This subgroup covers:
Subject matter of subgroup G03F 1/68 in which the processes for preparing radiation
modifying products and similar or like products include performing operations that are
ancillary to the manufacture or the design methods for these products, but which
ancillary operations (as auxiliary processes) are not specifically provided for in the
previous subgroups (e.g. cleaning or inspecting).
Informative references
Attention is drawn to the following places, which may be of interest for search:
Cleaning in general
B08B
Testing of optical apparatus
G01M 11/00
Methods or arrangements for reading or recognizing printed or
written characters or for recognizing patterns
G06K 9/00