Classifications

• • 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
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/26—Processing photosensitive materials; Apparatus therefor
  • G03F7/30—Imagewise removal using liquid means
  • G03F7/32—Liquid compositions therefor, e.g. developers
  • G03F7/325—Non-aqueous compositions
• • 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
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor

Definitions

• the present invention relates to a method for transferring topological images in which a layer of sensitive PBS (Poly Butene Sulfone) resin is coated with a layer of chromium oxide deposited on the surface of a substrate, the resin layer by applying appropriate radiation, for example an electron beam, on an area whose contour conforms to that of the image to be transferred, the resin is removed using a developing solvent sensitized in said zone and a rinsing is carried out, then the chromium oxide thus discovered locally is removed by etching, after which the remainder of non-sensitized resin is removed.
• PBS Poly Butene Sulfone
• the manufacture of these masks includes the inscription of a pattern on the surface of the substrate, delimited by an outline around which the chromium oxide is present.
• Photographic masks are used for image transfer by light printing.
• the glass substrate is transparent to light, while chromium oxide constitutes a barrier to the passage of light.
• the current and future technical needs of image transfer require the use of very fine geometry patterns implying a resolution less than a micrometer.
• the inscription of the pattern in chromium oxide is carried out by covering the thin layer of a photosensitive or electrose ⁇ sible polymer resin depending on the writing tool used. This organic resin is exposed or bombarded locally very precisely by appropriate means in order to prescribe a virtual image in the thickness of the polymer. The molecular structure of the resin is modified by this external energy supply. The organic polymer is then said to be sensitized.
• the virtual image is revealed by contact with one or more agents for dissolving the sensitized resin fraction.
• This development step which takes place in a liquid medium, is followed by a rinsing step which allows the elimination of the solubilizing agent and the entrainment of the partially dissolved polymer residues.
• the mask is then dried by the usual means.
• the image thus revealed leaves a protective layer of chromium oxide resin at the undisclosed locations.
• the elimination of chromium oxide by etching the areas not protected by the resin is obtained by chemical attack in a liquid medium, while the areas protected by the presence of the resin are not attacked.
• the protective resin leaves the pattern delimited by chromium oxide on the substrate.
• the PBS polymer resin chosen is electrosensitive and of positive polarity.
• This resin is therefore sensitized by the impact of an electron beam and it is the part thus insolated which will be sensitive to the action of the developing solvent.
• This polymer resin is currently widely used because of its high sensitivity to electronic impact. Writing a mask with an electron beam is a long operation, because the pattern is produced by the succession of very small elementary studs. The juxtaposition of these impacts creates the isolated geometric zone.
• the object of the present invention is to remedy the drawbacks of the current techniques mentioned above, by making it possible to carry out the revelation in a non-iterative and reproducible manner over time of the images written in the layer of PBS resin, as well as to dispense with hypersensitivity of the PBS resin to moisture.
• a mixture of monoethyl ether of ethylene glycol (product A) and isoamyl acetate (product B) is used, both as a developing solvent and as a rinsing solvent, product A being in the minority in the development solvent and in the majority in the rinsing solvent, while the product B is in the majority in the development solvent and in the minority in the rinsing solvent.
• the respective proportions of products A and B in the developing and rinsing solutions are variable depending on the degree of sensitization of the PBS resin.
• the mixture used as development solvent contains from 10 to 40% of product A and from 55 to 85% of product B and, for the rest, the sufficient quantity of additives and auxiliary substances to reach 100% .
• the mixture used as rinsing solvent it preferably contains from 70 to 90% of product A and from 5 to 25% of product B and, for the rest, the sufficient amount of additives and auxiliary substances to reach 100%.
• the rinsing step is started a little before the end of the development step.
• the rinser completes the action of the developer by allowing the final production of a layer of chromium oxide revealed free of any trace of resin and directly ready for the action of the etching solution, without any intermediate preparation.
• the method provides an appreciable time saving by eliminating the intermediate control steps, baking of the resin and pickling.
• the development processing followed by the etching can be carried out in one and the same equipment designed for this purpose, without interruption. As for the results obtained, it is observed that the profile of the edges of the resin is more abrupt, the process providing greater selectivity than the conventional treatment. In addition, the tolerance on the degree of sensitization of the resin is widened. The fact that the treatment takes place in a non-iterative mode increases the homogeneity of treatment on the surface of the mask.
• FIGS 1 to 4 illustrate schematically ent, in perspective, the main steps of the method according to the invention.
• This layer of resin is sensitized inside a surface area Z corresponding to an area to be removed from the layer 2 of chromium oxide, using an electron beam 4 displaced so as to create a multitude of punctual impacts inside the contour of zone Z. It is this sensitized part of the resin layer which will be sensitive to the action of an appropriate development solvent.
• the development solvent, or developer, used is a mixture containing 55 to 85% isoamyl acetate, of crude formula C -L.Op, and 10 to 40% of ethylene glycol monoethyl ether, of crude formula CF ⁇ O.
• the developer solution the temperature of which is controlled and regulated, is sprayed onto the resin surface of the substrate, kept flat on a rotary support rotating at a relatively slow speed.
• This spraying of solvent has the effect of eliminating the sensitized part of the resin layer 3 delimited by the contour of the zone Z (FIG. 2).
• the rinsing solution used contains a mixture of the same products, however in different proportions: the proportion of isoamyl acetate is now between 5 and 25%, that of monoethyl ether of ethylene glycol being between 70 and 90 %.
• the speed of rotation of the substrate is not modified for this second spraying, which lasts approximately 15 seconds.
• a second rinsing step consisting of a spraying of isopropyl alcohol, is then carried out. It also starts a few seconds (for example 5 seconds) before the end of the previous step. Then takes place a drying step, obtained by centrifugation. To this end, the speed of rotation of the substrate is increased until it reaches approximately 2000 rpm. The duration of this step is approximately 30 seconds.
• the etching of the area thus exposed of the layer 2 of chromium oxide can then begin. It is carried out by spraying an acid etching solution, for a suitable time, while the speed of rotation of the substrate is lowered to a low value. The part of layer 2 corresponding to zone Z is thus eliminated (FIG. 3). Then operations are carried out to remove the rest of the resin layer 3 (FIG. 4), to rinse with deionized water in a slow rotation regime for approximately 1 minute and to final dry, this latter operation being carried out in the same way. way that the first drying.
• the desired mask is completed, comprising the image of the zone Z transferred to the layer 2 of chromium oxide by selective elimination of the latter inside an zone faithfully reproducing the outline of the zone Z.
• composition of the solutions development and etching time, recovery time of certain successive stages, speed of rotation of the substrate at each stage, are largely dependent on the size of the mask to be produced and the degree of awareness. resin, and they should be adapted to each particular case.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Photosensitive Polymer And Photoresist Processing (AREA)
• Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)
• Preparing Plates And Mask In Photomechanical Process (AREA)
• Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9402386

Family Applications (1)

Country Status (6)

Family Cites Families (8)

• 1990
  • 1990-11-20 FR FR9014462A patent/FR2669442B1/fr not_active Expired - Fee Related
• 1991
  • 1991-11-14 KR KR1019930701503A patent/KR930703631A/ko not_active Withdrawn
  • 1991-11-14 WO PCT/FR1991/000894 patent/WO1992009012A1/fr not_active Ceased
  • 1991-11-14 JP JP4500419A patent/JPH06502502A/ja active Pending
  • 1991-11-14 EP EP92902063A patent/EP0558666A1/fr not_active Withdrawn
  • 1991-11-21 TW TW080109124A patent/TW202503B/zh active

Non-Patent Citations (1)

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