GB2165545A - Pellicle structure for transmission of mid ultraviolet light - Google Patents
Pellicle structure for transmission of mid ultraviolet light Download PDFInfo
- Publication number
- GB2165545A GB2165545A GB08523609A GB8523609A GB2165545A GB 2165545 A GB2165545 A GB 2165545A GB 08523609 A GB08523609 A GB 08523609A GB 8523609 A GB8523609 A GB 8523609A GB 2165545 A GB2165545 A GB 2165545A
- Authority
- GB
- United Kingdom
- Prior art keywords
- pellicle
- film
- cellulose acetate
- acetate butyrate
- nanometers
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000005540 biological transmission Effects 0.000 title claims description 26
- 229920006217 cellulose acetate butyrate Polymers 0.000 claims abstract description 19
- 239000000758 substrate Substances 0.000 claims abstract description 15
- 238000009987 spinning Methods 0.000 claims abstract description 8
- 238000000576 coating method Methods 0.000 claims description 23
- 238000000034 method Methods 0.000 claims description 17
- 239000011248 coating agent Substances 0.000 claims description 11
- 239000002904 solvent Substances 0.000 claims description 10
- 230000003595 spectral effect Effects 0.000 claims description 10
- JHIVVAPYMSGYDF-UHFFFAOYSA-N cyclohexyloxide Natural products O=C1CCCCC1 JHIVVAPYMSGYDF-UHFFFAOYSA-N 0.000 claims description 9
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 8
- 125000004063 butyryl group Chemical group O=C([*])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 claims description 7
- 239000000377 silicon dioxide Substances 0.000 claims description 4
- 238000001914 filtration Methods 0.000 claims description 2
- 238000004528 spin coating Methods 0.000 claims description 2
- 239000010408 film Substances 0.000 claims 12
- 239000010409 thin film Substances 0.000 claims 5
- 229920000875 Dissolving pulp Polymers 0.000 claims 1
- UGZICOVULPINFH-UHFFFAOYSA-N acetic acid;butanoic acid Chemical compound CC(O)=O.CCCC(O)=O UGZICOVULPINFH-UHFFFAOYSA-N 0.000 claims 1
- 125000002243 cyclohexanonyl group Chemical group *C1(*)C(=O)C(*)(*)C(*)(*)C(*)(*)C1(*)* 0.000 claims 1
- 230000005855 radiation Effects 0.000 abstract description 4
- 239000000428 dust Substances 0.000 abstract description 3
- 239000002245 particle Substances 0.000 abstract description 3
- 239000000463 material Substances 0.000 description 13
- 238000001393 microlithography Methods 0.000 description 9
- 229920001220 nitrocellulos Polymers 0.000 description 9
- 239000012528 membrane Substances 0.000 description 7
- 239000000020 Nitrocellulose Substances 0.000 description 6
- 239000011521 glass Substances 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- FERIUCNNQQJTOY-UHFFFAOYSA-N Butyric acid Natural products CCCC(O)=O FERIUCNNQQJTOY-UHFFFAOYSA-N 0.000 description 2
- 229940081735 acetylcellulose Drugs 0.000 description 2
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 2
- 229910001634 calcium fluoride Inorganic materials 0.000 description 2
- 229920002301 cellulose acetate Polymers 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229920002120 photoresistant polymer Polymers 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 235000012431 wafers Nutrition 0.000 description 2
- KNKRKFALVUDBJE-UHFFFAOYSA-N 1,2-dichloropropane Chemical class CC(Cl)CCl KNKRKFALVUDBJE-UHFFFAOYSA-N 0.000 description 1
- ZAMLGGRVTAXBHI-UHFFFAOYSA-N 3-(4-bromophenyl)-3-[(2-methylpropan-2-yl)oxycarbonylamino]propanoic acid Chemical compound CC(C)(C)OC(=O)NC(CC(O)=O)C1=CC=C(Br)C=C1 ZAMLGGRVTAXBHI-UHFFFAOYSA-N 0.000 description 1
- 229920002799 BoPET Polymers 0.000 description 1
- FERIUCNNQQJTOY-UHFFFAOYSA-M Butyrate Chemical compound CCCC([O-])=O FERIUCNNQQJTOY-UHFFFAOYSA-M 0.000 description 1
- 239000004593 Epoxy Substances 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- 101100345589 Mus musculus Mical1 gene Proteins 0.000 description 1
- 239000005041 Mylar™ Substances 0.000 description 1
- -1 acetal butyrate Chemical class 0.000 description 1
- DHKHKXVYLBGOIT-UHFFFAOYSA-N acetaldehyde Diethyl Acetal Natural products CCOC(C)OCC DHKHKXVYLBGOIT-UHFFFAOYSA-N 0.000 description 1
- 150000001242 acetic acid derivatives Chemical class 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 239000006117 anti-reflective coating Substances 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 235000010980 cellulose Nutrition 0.000 description 1
- 229920006265 cellulose acetate-butyrate film Polymers 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 229920006333 epoxy cement Polymers 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 239000012943 hotmelt Substances 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229920000052 poly(p-xylylene) Polymers 0.000 description 1
- 239000011253 protective coating Substances 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
- C08J5/18—Manufacture of films or sheets
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C41/00—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
- B29C41/02—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor for making articles of definite length, i.e. discrete articles
- B29C41/12—Spreading-out the material on a substrate, e.g. on the surface of a liquid
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F1/00—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
- G03F1/62—Pellicles, e.g. pellicle assemblies, e.g. having membrane on support frame; Preparation thereof
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2001/00—Use of cellulose, modified cellulose or cellulose derivatives, e.g. viscose, as moulding material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2001/00—Use of cellulose, modified cellulose or cellulose derivatives, e.g. viscose, as moulding material
- B29K2001/08—Cellulose derivatives
- B29K2001/12—Cellulose acetate
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
- B29K2105/0058—Liquid or visquous
- B29K2105/0073—Solution
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2301/00—Characterised by the use of cellulose, modified cellulose or cellulose derivatives
- C08J2301/08—Cellulose derivatives
- C08J2301/14—Mixed esters
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Materials Engineering (AREA)
- Physics & Mathematics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Preparing Plates And Mask In Photomechanical Process (AREA)
- Laminated Bodies (AREA)
- Manufacture Of Macromolecular Shaped Articles (AREA)
Abstract
A freely standing thin pellicle film of cellulose acetate butyrate is formed by spinning on a rotating substrate. After forming, the film is lifted off of the substrate and secured to a metallic frame. The pellicle is for use in the mid ultraviolet range of 280 to 360 nanometers, but can be used also in the deep ultraviolet range, e.g. wavelengths as low as about 240 nanometers. The pellicle prevents dust particles from being focused on a surface which is to be exposed by the ultraviolet radiation.
Description
SPECIFICATION
Pellicle structure for transmission of mid ultraviolet light
Background of the invention
This invention relates to a pellicle structure used for the protection of photo masks and reticles in microlithography applications and, more specifically, relates to a novel pellicle structure which can transmit an average of about 90% or greater over a radiation band width beginning at about 240 nanometers.
Pellicles, which are free standing thin transparent organic films are commonly used to protect photo masks and reticles in order to increase die yield in microlithography during the manufacture of semiconductor devices. Such pellicles are normally attached to a mask used in the microlithography application and stand above the mask surface by a given distance. Thus, dust particles which may settle during the microlithography operation will settle on the pellicle and be defocused on the work surface.
Consequently, when used in a conventional photolithographic apparatus, one or more dust particles will not affect the yield of a given wafer. Die yield from such wafers is improved by up to and greater than 40% when the mask andlor reticle are pellicle
protected.
Pellicles of this type are described in a publication
by R. Hershel, Semiconductor International,8,97, (1981). Their use is also described in a publication by
A. Rangappan, C. Kao, "SPIE Optical Microlithogra
phy", Vol.334,52. (1982). Also see I. Ward, Dawn
Duly, SPIE, Vol.470, Optical Microlithography Ill:
Technology for the Next Decade (1984), pp. 147-156.
A standard pellicle being sold today, for example
by the assignee of the present application, consists
of a membrane which is commonly of nitrocellulose
having a thickness of about 2.85 microns. Such
nitrocellulose pellicles satisfy the light transmission
requirements for most present microlithography
applications. Films other than nitrocellulose are also
known for use as pellicles. By way of example, films
have been made of materials such as mylar, cellu
lose acetate, parylene (poly(chloro-p-xycylene)) and
cellulose acetate (without butyrate). Other materials
are also known and the foregoing is not an exhaus
tive list. Nitrocellular pellicles do not transmit suffi
cient light at shorter wavelengths, for example
below 360 nanometers.However, there is a growing
need for pellicle materials which can transmit useful
amounts of an input light in the mid range of
ultraviolet wavelengths, particularly in the 280 to 360
nanometer range. Such materials must also permit
relatively economical manufacture and have mecha
nical durability which will enable them to exist as a
free standing membranes which are not too rapidly
degraded by ultraviolet radiation and can withstand
at least minimal mechanical abuse during handling
and cleaning. Moreover, the pellicle film must be
capable of being made thin enough and of sufficient
uniformity so as to not interfere with the optical
properties of the microlithographic process.
Brief summary of the invention
In accordance with the present invention, pellicle membranes of cellulose acetate butyrate in a range of formulations have been found to satisfy the ultraviolet transmissions and durability properties required of free standing membranes at ultraviolet frequencies in the deep and mid ultraviolet ranges of 240 to 290 nanometers and 290 to 360 nanometers, respectively. More particularly, the novel membrane of the invention is useful at frequencies beginning at about 240 nanometers, particularly when antireflection coatings are used. Indeed, the use of an antireflection coating on both surfaces of the cellulose acetate butyrate membrane of the invention permits transmission at frequencies as low as the cut-off transmission frequency of silica mask substrates which is approximately 190 nanometers.
A preferred cellulose acetate butyrate composition employs about 15% butyryl, and a 15 sec viscosity.
The butyryl content can vary from 5% to 40%. Its viscosity can vary from 5 sec to 20 sec. This material is available from Eastman Kodak under their catalog number 4623, CAS Registry No. 9004-36-8. This material is offered for sale by Eastman Kodak for use as a hot melt or as a strippable coating used for high-gloss coatings and protective coatings, respectively. Eastman Kodak cellulose acetal butyrate coatings are described in their bulletins No. 3.4A, E-101B, and E-184A, each of which is dated July, 1973.Note that these coatings are not suggested by
Eastman Kodak to be capable of free standing use as a transparent film but are always intended to be fixed in surface to surface contact with a substrate such as a wooden surface which is to have a desired finish appearance or a metallic surface which is to be protected by the film which ordinarily adheres to its surface.
It was found that this material can be dissolved in a suitable solvent, preferably cyclohexanone, to a workable viscosity which enables the material to be filtered and then spin-coated on a glass substrate.
For example, from 3% to 10% of the cellulose acetate butyrate, by weight, solids content, can be dissolved in cyclohexanone. The substrate can be rotated at any appropriate speed selected from about 300 rpm to about 2,000 rpm and is spun for a time depending on the desired thickness to be obtained. This time will also depend upon atmospheric conditions and solvent concentration in the spinning appratus. It was found that the spin coating process inherently forms an acceptably thin coating and by suitable
adjustment of speeds and other parameters a thick
ness of 2.85 microns can be obtained in a repeatable
manner within suitable tolerances by spinning at from 400 to 600 rpm, nominally, at 500 rpm. Film thicknesses from 1 micron to 5 microns can be made
by appropriate adjustment of the process.
Thereafter, the substrate and film thereon is
loaded into a water bath and the film is loosened from the glass substrate and secured to the end of a
metal frame as by cementing with an epoxy type
cement or the like.
The film may also be coated on one or both
surfaces with an antireflection coating of known composition, for example calcium fluoride. The index of refraction of the cellulose acetate butyrate is approximately that of nitrocellulose so that the low reflectivity coating will be almost as effective on membranes of either material.
The novel pellicle film of the invention and having a thickness, for example of 2.85 microns has the novel characteristic in the mid ultraviolet range which extends between 280 nanometers and 360 nanometers that it transmits an average of about greater than 90% of incident light without the use of antireflection coatings. Moreover, there is substantial light transmission into the deep ultraviolet range which is less than about 280 nanometers. When the surfaces of the pellicle of the invention are provided with one or more antireflection coatings, transmission in the deep ultraviolet range is further improved such that an average greater than 90% transmission is obtained at frequencies above about 240 nanometers. When coated with one or more antireflection coatings, the film will transmit greater than about 90% of incident light and the band of 240 nanometers to 600 nanometers.
The pellicle was also found to have improved mechanical durability, better resistance to chemicals used to clean pellicles, and is not deteriorated adversely by mid ultraviolet radiation.
Brief description of the drawings
Figure 1 is a top view of a portion of a silica mask which has a conductive coating thereon and a pellicle secured thereto.
Figure 2 is a cross-sectional view of Figure 1 taken across the section line 2-2 in Figure 1.
Figure 3 shows the spectral transmission for a prior art nitrocellulose pellicle having a thickness of 2.85 microns.
Figure 4 shows the spectral transmission charac teristicforthe nictocellulose pellicle of Figure 3 when it is coated with an antireflection coating on one side of the pellicle film.
Figure shows a prior art pellicle of the type shown in Figure 3 with antireflection coatings on both surfaces of the pellicle film.
Figure 6 shows the spectral transmission of a pellicle film of cellulose acetate butyrate made in accordance with the invention and demonstrates its improved transmission in the deeper ultraviolet regions.
Figure 7 illustrates the characteristics of the cellulose acetate butyrate pellicle film of Figure 6 when one side is covered with an antireflection coating.
Figure 8 shows the spectral transmission characteristic of the film of Figure 6 when both sides are coated with an antireflection coating.
Detailed description of the invention
Figures 1 and 2 illustrate a conventional pellicleized mask wherein a silica mask 10 is a standard mask having a metallized pattern 11 on its upper surface (Figure 2). The pellicle shown in Figures 1 and 2 consists of a thin organic film 12 which is fastened to a rectangular metal frame 13 which will have a shape dependent upon the manner in which the mask is to be mounted in the projection aligner or step and repeat aligner used for the microlithography process. The film area can be any area desired or necessary in the microlithography application and will match the shape of the underlying mask.
Film 12 has been made of numerous materials in the past, notably nitrocellulose having a thickness of 2.85 microns. Other thicknesses have also been used, for example 0.865 microns. A commercially available pellicle manufactured by the assignee of the present application is a nitrocellulose film pellicle known as "Type 1" having a thickness of 2.85 microns and a spectral transmission characteristic which is shown in Figure 3.
In Figure 3, the horizontal axis of the graph is wavelength in nanometers of a standard high pressure mercury lamp while the vertical axis shows the percentage transmission of light through the pellicle.
Conventionally, the pellicle of Figure 3 is preferably operated at the i, hand g wavelengths which are shown in dotted lines in the band between 350 and 450 nanometers. Note particularly that the pellicle having the characteristic of Figure 3 cannot be used in relatively deep ultraviolet application since the transmission of light is sharply reduced below about 360 nanometers.
Nitrocellulose films having the characteristic of
Figure 3 can be made by numerous processes, preferably a spinning process employing the weliknown technology used in spinning photoresists onto a substrate. The films are then conventionally lifted off in a water bath and cemented to frames such as the frame 13 of Figures 1 and 2 so that they are stretched tautly on the frame.
In order to improve its spectral transmission characteristics, it is known to apply an antireflection coating on one surface of the pellicle. This improves the characteristic to that shown in Figure 4 for the nitrocellulose film of 2.85 microns.
A still further improvement in the light transmission of the pellicle can be obtained by using an antireflective coating on both sides of the pellicle film as shown in Figure 5. These antireflection coatings can be any desired type, for example calcium fluoride coatings which are applied by conventional known processes.
In accordance with the present invention, the film 12 of Figures 1 and 2 is made of a cellulose acetate butyrate. In a preferred embodiment of the invention, the cellulose acetate butyrate contained about 15% butyryl and had a 15 sec viscosity. The material is commercially available from Eastman Kodak; catalog material No. 4623, CAS Registry No. 9004-36- 8. The viscosity can vary in the range of from 5 sec to 20 sec and the butyryl content can vary between 5% and 40%. Three percent to 10% solids by weight, preferably 6% of this material was dissolved in cyclohexanone to a workable viscosity and was then filtered and thereafter spin coated on a glass substrate. Other solvents can be used, for example, organic acetates, keytones, ethylene and propylene chlorides. These will produce good films, but cyclohexanone lent itself to good filtering.
The spinning process is essentially identical to conventional spin processes used for spinning photoresists onto a substrate. Thus, in solutions with 3% to 10% solids, spin rates of 300 to 2,000 rpm can be used to produce pellicles in a range of thicknesses from 1 micron to 5 microns. For a 2.85 micron thick pellicle, and using 6% solids by weight, the spin speed is from 400 to 600 rpm, nominally 500 rpm.
After forming the film, the substrate and film are placed in a water bath and the film is separated from the glass substrate. The film is then appropriately cemented to a support frame (support frame 13 of
Figures 1 and 2) by a suitable epoxy cement and extends tautly across the frame.
When the pellicle film had a thickness of 2.85 microns, the spectral transmission characteristics shown in Figure 6 were obtained. When the film was coated on one surface or two surfaces respectively, the characteristics of Figures 7 and 8, respectively, were obtained.
In examining the spectral transmission characteristics of Figure 6, it will be observed that the spectral transmission of the 2.85 micron cellulose acetate butyrate film at 240 nanometers is greater than about .72% and, at 250 nanometers, peaks at about 90%. These transmission characteristics are adequate for application in the deep ultraviolet region in photomicrolithography applications. The transmission is substantially improved by use of antireflection coatings on one or both pellicle surfaces. Thus, in Figure 7, it will be seen that the transmission at 240 nanometers is substantially greater than 80%, and in Figure 8, approaches 90%.
Although the present invention has been described in connection with a preferred embodiment thereof, many variations and modifications will now become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.
Claims (21)
1. A pellicle comprising a thin film of substantially uniform thickness which is tautly fixed to one edge of an enclosed frame; said thin film consisting of cellulose acetate butyrate.
2. The pellicle of claim 1, wherein said thin uniform film has a thickness of from about 1 micron to about 5 microns.
3. The pellicle of claim 1, wherein the opposite edge of said enclosed frame is adapted for mounting to a silica mask.
4. The pellicle of claim 1, wherein said thin film in the absence of antireflection coatings has a spectral transmission characteristic whereby an average greater than bout 90% of incident light in the band of frequencies from 280 nanometers to 360 nanometers is passed by said film.
5. The pellicle of claim 1, wherein said thin film has an antireflection coating on one of its surfaces.
6. The pellicle of claim 5, wherein said thin film transmits greater than about 90% of incident light in the band of 240 nanometers to 600 nanometers.
7. The pellicle of claim 3, wherein said thin uniform film has a thickness of about 2.85 microns.
8. The pellicle of claim 4, wherein said thin uniform film has a thickness of about 2.85 microns.
9. The pellicle of claim 5, wherein said thin uniform film has a thickness of about 2.85 microns.
10. The pellicle of claim 6, wherein said thin uniform film has a thickness of about 2.85 microns.
11. A process of making a pellicle comprising the steps of dissolving cellulose acetate butyrate in a solvent, filtering said dissolved cellulose acetate butyrate and solvent, spin coating said cellulose acetate butyrate and solvent on a spinning substrate and driving off said solvent to form a substantially uniformly thick film of cellulose acetate butyrate, lifting said film from said substrate and cementing said film to one end of a support frame with said film tautly stretched over said frame.
12. The process of claim 11, wherein said cellulose acetate butyrate contains from 5% to 40% butyryl, and has a viscosity of from 5 sec to 20 sec.
13. The process of claim 12, wherein said solvent is cyclohexanone.
14. The process of claim 11, wherein said cellulose acetate butyrate has about 15% butyryl and a viscosity of about 15 sec.
15. The process of claim 13, wherein said cellulose acetate butyrate has about 15% butyryl and a viscosity of about 15 sec.
16. The process of claim 11, wherein from 3% to 10% by weight of said cellulose acetate butyrate is dissolved in said solvent.
17. The process of claim 13, wherein from 3% to 10% by weight of said cellulose acetate butyrate is dissolved in said solvent.
18. The process of claim 16, wherein said spin rate is in the range of 300 to 2,000 rpm.
19. Pellicle film whenever made by the process claimed in any one of claims 11 to 18:
20. A pellicle film substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
21. A process for making a pellicle substantially as hereinbefore described.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US66157784A | 1984-10-16 | 1984-10-16 |
Publications (3)
Publication Number | Publication Date |
---|---|
GB8523609D0 GB8523609D0 (en) | 1985-10-30 |
GB2165545A true GB2165545A (en) | 1986-04-16 |
GB2165545B GB2165545B (en) | 1988-03-30 |
Family
ID=24654183
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB08523609A Expired GB2165545B (en) | 1984-10-16 | 1985-09-25 | Pellicle structure for transmission of mid ultraviolet light |
Country Status (5)
Country | Link |
---|---|
JP (1) | JPH065383B2 (en) |
DE (1) | DE3536708A1 (en) |
FR (1) | FR2573219B1 (en) |
GB (1) | GB2165545B (en) |
IT (1) | IT1187747B (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0314418A2 (en) * | 1987-10-26 | 1989-05-03 | Mitsui Petrochemical Industries, Ltd. | Dust-proof film |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5950467B2 (en) * | 2013-09-24 | 2016-07-13 | 信越化学工業株式会社 | Pellicle |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB716398A (en) * | 1952-07-07 | 1954-10-06 | Rose Rand | Improvements in or relating to purses or handbags |
GB1184008A (en) * | 1967-12-15 | 1970-03-11 | Polaroid Corp | Optical Devices Comprising Cellulose Acetate and Cellulose Acetate Butyrate |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4453828A (en) * | 1981-12-02 | 1984-06-12 | Advanced Semiconductor Products, Inc. | Apparatus and methods for measuring the optical thickness and index of refraction of thin, optical membranes |
JPS58219023A (en) * | 1982-06-15 | 1983-12-20 | Daicel Chem Ind Ltd | Manufacture of resin membrane |
US4482591A (en) * | 1983-03-08 | 1984-11-13 | J. T. Baker Chemical Company | Polyvinyl butyrate pellicle compositions and pellicles thereof for projection printing |
-
1985
- 1985-09-25 GB GB08523609A patent/GB2165545B/en not_active Expired
- 1985-10-02 IT IT22329/85A patent/IT1187747B/en active
- 1985-10-03 FR FR858514692A patent/FR2573219B1/en not_active Expired
- 1985-10-15 DE DE19853536708 patent/DE3536708A1/en not_active Withdrawn
- 1985-10-16 JP JP23088085A patent/JPH065383B2/en not_active Expired - Lifetime
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB716398A (en) * | 1952-07-07 | 1954-10-06 | Rose Rand | Improvements in or relating to purses or handbags |
GB1184008A (en) * | 1967-12-15 | 1970-03-11 | Polaroid Corp | Optical Devices Comprising Cellulose Acetate and Cellulose Acetate Butyrate |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0314418A2 (en) * | 1987-10-26 | 1989-05-03 | Mitsui Petrochemical Industries, Ltd. | Dust-proof film |
EP0314418A3 (en) * | 1987-10-26 | 1991-01-30 | Mitsui Petrochemical Industries, Ltd. | Dust-proof film |
Also Published As
Publication number | Publication date |
---|---|
IT8522329A0 (en) | 1985-10-02 |
GB2165545B (en) | 1988-03-30 |
IT1187747B (en) | 1987-12-23 |
JPS61106243A (en) | 1986-05-24 |
FR2573219A1 (en) | 1986-05-16 |
DE3536708A1 (en) | 1986-04-17 |
GB8523609D0 (en) | 1985-10-30 |
JPH065383B2 (en) | 1994-01-19 |
FR2573219B1 (en) | 1989-02-03 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) | ||
PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19980925 |