scispace - formally typeset
Search or ask a question

Showing papers on "Photomask published in 1987"


Patent
05 Oct 1987
TL;DR: In this paper, an automatic inspection system including an illuminator for illuminating a reticle or photomask to be inspected, while optically projecting a magnified image of the reticle/photomask onto a plurality of detector elements.
Abstract: An automatic inspection system including an illuminator for illuminating a reticle or photomask to be inspected, while optically projecting a magnified image of the reticle or photomask onto a plurality of detector elements. A carriage assembly moves the object at a constant velocity to allow the detector elements to sequentially view the entire surface to be inspected. The detector elements are responsive to the intensity of light incident thereupon and are periodically scanned to obtain a two-dimensional measured representation of the object. A database adaptor formulates a two-dimensional representation from the design database description corresponding to the scanned object simultaneously and in synchronism with the scanning of the photomask or reticle. The measured and database adapted representation of the scanned object are input to a signal processor for alignment and defect detection. While the representations are shifted through a memory, an alignment circuit dynamically measures and corrects for misalignment between the representations, so that a defect detector can effectively compare the representations for defects. Additional correction of misalignment between the representations is obtained by modulating the size of the measured representation as detected by the detector elements. At the operator's option, a second measured image of a multi-cell reticle or photomask may be used for comparison as a substitute for the database representation.

172 citations


Patent
08 Sep 1987
TL;DR: The disclosed process as discussed by the authors is a process for reducing the image size of an integrated circuit by depositing a conformal layer to the interior vertical surfaces of the opening, followed by anisotropic etching.
Abstract: Disclosed is a process for reducing lithographic image size for integrated circuit manufacture. A mask (14) of photosensitive material having an opening (20) of a minimum size (A) dictated by the limits of lithography is formed on a substrate (10). Reduction in the image size is achieved by establishing sidewalls (24) to the interior vertical surfaces of the opening by depositing a conformal layer (22), followed by anisotropic etching. The dimension (C) of the new opening is reduced by the combined thickness of the two opposite insulator sidewalls. In a specific direct application of the disclosed process, a photomask/stencil having a pattern of openings of a minimum size smaller than possible by lithography, per se, is formed.

165 citations


Patent
31 Jul 1987
TL;DR: The disclosed process as mentioned in this paper reduces the image size by establishing sidewalls to the interior vertical surfaces of the opening by depositing a conformal layer, followed by anisotropic etching.
Abstract: Disclosed is a process for reducing lithographic image size for integrated circuit manufacture. A mask of photosensitive material having an opening of a minimum size dictated by the limits of lithography is formed on a substrate. Reduction in the image size is achieved by establishing sidewalls to the interior vertical surfaces of the opening by depositing a conformal layer, followed by anisotropic etching. The dimension of the opening is reduced by the combined thickness of the two opposite insulator sidewalls. In a specific direct application of the disclosed process, a photomask/stencil having a pattern of openings of a minimum size smaller than possible by lighography, per se, is formed.

38 citations


Journal ArticleDOI
TL;DR: In this article, the use of focused ion beams was used to repair the mask stain caused by excess of chromium ionization during the repair process of a chromium-on-glass mask.
Abstract: Optical lithography of semiconductor microcircuits relies upon the use of chromium-on-glass masks or reticles. Opaque defects in the mask pattern due to excess of chromium can be repaired by the use of focused ion beams and commercial mask repair systems are now available. During the repair process, ions are implanted into the glass substrate of the mask, giving rise to a stain when the mask is inspected or used for lithography.

25 citations


Proceedings ArticleDOI
L. R. Harriott1
30 Jun 1987
TL;DR: The second generation micromachining system as mentioned in this paper was developed at AT&T Bell Laboratories for applications including photomask repair, integrated circuit modification, and fabrication of integrated optical structures.
Abstract: We present a description of our second generation micromachining system. This machine has been developed at AT&T Bell Laboratories for applications including photomask repair, integrated circuit modification, and fabrication of integrated optical structures. The architecture incorporates many of the features and capabilities found separately in other systems, in a unique combination with emphasis on flexibility and ease of operation. The hardware features a 30 KeV Gallium beam with a one millimeter deflection field and 250 mm by 300 mm stage travel. Provisions have been made for secondary electron and ion imaging, charge neutralization, gas phase material deposition and secondary ion mass spectroscopy (SIMS).

22 citations


Patent
31 Jul 1987
TL;DR: In this article, the phase shifters are disposed in a part or the whole of the photomask to be used as the original plate at the time of exposing the image with an exposure device using the deformed illumination.
Abstract: PURPOSE:To improve resolution and depth of focus by disposing phase shifters on a photomask to be used as an original plate and optically combining a deformed illumination method and a phase shift method. CONSTITUTION:The phase shifters are disposed in a part or the whole of the photomask to be used as the original plate at the time of exposing the photomask with an exposure device using the deformed illumination. The phase shifters preferably consist of a shifter thickness different from the shift thickness to apply the phase shift of 0.5 times the exposure wavelength. For example, the phase shift mask to be used is not the conventional phase shift mask of applying the phase shift of lambda/2 but is the phase shift mask of, for example, lambda/4 The phase shift quantity varies from lambda/2 when this phase shifters are imparted to the mask patterns 2 finer than the optimum line width/inter-line spacing and, therefore, the zero order diffracted light is not completely erased and is suppressed to the extent that the light is weakened. Further, the effect of weakening the intensity of the zero order diffracted light eventually makes up the defect of the low contrast of the projected image possessed by the deformed illumination exposure device.

21 citations


Patent
01 Dec 1987
TL;DR: In this paper, a process for producing a blazed diffraction grating by using a transmission modulation Diffraction Grating as a photomask in photolithography is described.
Abstract: The present invention provides a process for producing a blazed diffraction grating by using a transmission modulation diffraction grating as a photomask in photolithography. The photomask is composed of a relief modulation diffraction grating (A) made of a transparent material and a blazed diffraction grating (B) made of a material containing a ray absorbing agent. The diffraction grating (A) and the diffraction grating (B) are mated with each other through their grating surfaces.

19 citations


Patent
16 Nov 1987
TL;DR: In this article, a solution of photoresist is used to spray over the projection surface of a printed circuit substrate to expose the entire projection surface, followed by a photomask having a plurality of planar images, each image being positioned parallel to the others but separated by a small distance.
Abstract: Printed circuit patterns are photolithographically defined on a three dimensional "projection" surface (204) of a printed circuit substrate (202) using a projection image aligner and a photomask (210) having a planar image (210A). The geometry of the projection is restricted such that the slope of the projection surface, as measured at any point on the projection surface and relative to a reference plane which is parallel to the focal plane of the projection image aligner, is less than 90 degrees. A solution of photoresist includes a photoresist solvent, a fluorosurfactant and an aromatic hydrocarbon solvent, and is preferably sprayed over the projection surface. In one method of manufacture, the printed circuit substrate is moved from one position to another during the exposure of the photoresist layer (206). In another method, after a first portion of the projection surface is exposed by a first photomask (502), a second photomask (504) is substituted and the remainder of the projection surface exposed. In still another method, a photomask having a plurality of planar images (604A, 604B and 606A) each image being positioned parallel to the others but separated by a small distance, is used to simultaneously exposed the entire projection surface.

14 citations


Patent
18 Feb 1987
TL;DR: In this article, a projection exposure apparatus has a pattern lighting optical system including an exposure light source for lighting a pattern on a photomask, a projection optical system for forming an image of the pattern lighted by the exposure light sources on the surface of a wafer, and an alignment lighting illumination system for detecting relative positional relationship between the mask pattern and the wafer.
Abstract: A projection exposure apparatus has a pattern lighting optical system including an exposure light source for lighting a pattern on a photomask, a projection optical system for forming an image of the pattern lighted by the exposure light source on the surface of a wafer, an alignment lighting optical system including an alignment light source for lighting alignment marks on the photomask and the wafer, and an alignment optical system for detecting relative positional relationship between the mask pattern and the wafer through the projection optical system, and further the projection optical system includes an image-forming system which exhibits two extremums of axial aberration as a function of wavelength.

14 citations


Patent
Willis Seifert1
24 Dec 1987
TL;DR: In this article, an apparatus for removing a pellicle that is adhesively bonded to a photomask is described, where a pair of blades are mounted on a carriage that is longitudinally movable within the housing.
Abstract: An apparatus for removing a pellicle that is adhesively bonded to a photomask. A first embodiment of the invention is provided for removing a pellicle having a generally rectangular shape. The photomask is placed in a housing with the pellicle facing down. A pair of blades are mounted on a carriage that are longitudinally movable within the housing. The blades are adjustable such that the cutting edges are immediately below the surface of the photomask. The carriage is driven by a rack and pinion assembly causing the blades to cut through the adhesive layer bonding the pellicle to the photomask. A second embodiment of the invention is provided for removing a pellicle having a generally circular shape. In this embodiment, the blades are mounted on a rotating bar. Rotation of the bar causes the blades to cut through the adhesive layer bonding the pellicle to the photomask.

11 citations


Patent
21 Jan 1987
TL;DR: In this article, an exposure apparatus for arranging an photomask having a plurality of alignment marks to face a surface to be exposed of a board has been proposed, where contours of the larger alignment marks encircle the smaller alignment marks when the board is overlapped with the photOMask.
Abstract: An exposure apparatus for arranging an photomask having a plurality of alignment marks to face a surface to be exposed of a board having a plurality of corresponding alignment marks with the alignment marks of the photomask and the board being aligned to each other, to expose the board by radiating light through the photomask. The alignment marks of the board are different in size from the alignment marks of the photomask, whereby contours of the larger alignment marks encircle the smaller alignment marks when the board is overlapped with the photomask. In this state, the respective positions of the alignment marks of the board and the photomask are detected. The positions of the alignment marks thus detected are compared with each other to obtain displacement from desired positions, so that the photomask is moved in its surface direction to correct the displacement.

Patent
Feely Wayne Edmund1
12 Jan 1987
TL;DR: In this paper, a process for thermally stable microplastic structures and processes for their manufacture are described. Butterfly structures are prepared from crosslinkable photosensitive compositions using one or more suitable photomasks, e.g. a specially designed radiation attenuating photomask.
Abstract: Thermally stable microplastic structures and processes for their manufacture are provided. The microplastic structures are prepared from crosslinkable photosensitive compositions using one or more suitable photomasks, e.g. a specially designed radiation attenuating photomask, which permits preselection of the size, length, width and thickness of the desired structure. The microplastic structures are stable at temperatures in excess of 200°C and can, for example, be used as components in miniature electrical, mechanical, chemical and optical devices, such as smart sensors integral to a silicon chip device.

Patent
21 Feb 1987
TL;DR: In this article, a pattern a is provided on a plate made of glass, quartz etc., and a lubricant such as Teflon resin etc. on the surface of the photomask.
Abstract: PURPOSE:To prevent close adhesion of a photomask and resist and to prevent the occurrence of resist separation by coating a lubricant such as 'Teflon(R)' resin etc. on the surface of the photomask. CONSTITUTION:A pattern a is provided on a plate made of glass, quartz etc., and a lubricant such as Teflon resin etc. is coated on the pattern by a spin coater to form a lubricant layer 9. A photomask 4' is placed on a mask stage 10 and fixed by vacuum adsorption 11. A wafer 1 on which resist 3 is applied is placed on a wafer stage 12. The wafer stage 12 is fixed to a vertically movable shaft 13, and the shaft 13 is connected to a pulse motor. The shaft 13 is raised by rotation of the pulse motor, and the wafer 1 is brought into contact with the photomask 4'. At this time, the wafer 1 is exhausted as shown by the arrow mark A, and closely adhered fixing is made. When the photomask 4' is detached from the wafer 1 after exposure by light, close adhesion of the photomask 4' and resist 3 is prevented, and separation of resist does not occur owing to coating of the lubricant layer 9 of Teflon.

Patent
18 Apr 1987
TL;DR: In this paper, a photomask is cleaned and held in the vapor of alkylfluoroalkoxysilane to arrange fluoroalkyl groups on the surface of the photOMask.
Abstract: PURPOSE:To easily form a protective coating film on a photomask by cleaning the photomask and bringing it into contact with the vapor of alkylfluoroalkoxysilane. CONSTITUTION:The photomask is cleaned and held in the vapor of alkylfluoroalkoxysilane to arrange fluoroalkyl groups on the surface of the photomask. The alkylfluoroalkoxysilane is obtd. by substituting a fluoroalkyl group for at least one alkyl group represented by a formula ClH2l+1 in alkylalkoxysilane represented by formula I.

Patent
14 Apr 1987
TL;DR: In this article, the authors proposed an electroconductive thin film made of a tantalum oxide having a specific transmissivity and a thickness of the thin film on a transparent substrate and then by providing a thin film having a light shaft property on the prescribed film.
Abstract: PURPOSE:To prevent the generation of the discharge phenomenon of an static electricity which has especially tendency for generating in the large sized photomask and to improve an transparency of the titled photomask and an adhesive property between said photomask and its adjacent layer by providing an electroconductive film made of a tantalum oxide having a specific transmissivity and a thickness of the thin film on a transparent substrate and then by providing a thin film having a light shaft property on the prescribed film. CONSTITUTION:The titled photomask is composed of the electroconductive thin film 2 which is made of the tantalium oxide (TaOx:X =75% transmissivity against a light having a photosensitive range of a photosensitive resin provided on the transparent substrate, and the thin film 3 having a light shade property against the prescribed light provided on said film 2. When the X is 25, said tantalium oxide means the tantalium penta oxide (Ta2O5) which is a complete insulator and does not display an electrically conductivity. When said film is thinner than that of 30Angstrom , its conductivity is a rather insufficient. While when said film is thickener than that of 80Angstrom , as the film does not display >=75% the transmissivity against the prescribed light, it is not preferable. The optimum value of the thickness of the film is 40-60Angstrom . Thus, the surface resistance value of said film is 10-20kOMEGA/cm and is preferable.

Proceedings ArticleDOI
30 Jun 1987
TL;DR: In this paper, a rigid SiC-W-membrane and a stress compensated W-absorber system are used for X-ray stepper mask fabrication with a smooth surface and Young's modulus as high as the bulk value.
Abstract: This paper deals with the development of an X-ray stepper mask technology based on a rigid SiC.-membrane and a stress compensated W-absorber system. The SiC-mask blanks are being fabricated using batch processes like CVD-deposition and selective thin etching. As a result of extensive process optimization the polycristalline membranes can be fabricated with a smooth surface (< 40 nm) and a Young's modulus as high as the bulk value (4.6*10 11 N/m 2). Membranes of 2.7 μm in thickness are being prepared routinely with excellent transparency for synchrotron and optical radiation. For a high X-ray absorption and low thermal expansion sputter deposited tungsten has been applied. Ihe proposed stress compensating technique enables absorber stresses of less than 1*107 N/m , resulting in a mask distortion of < 100 nm. Precise sub-0.5-micron pattern with steep profiles have been generated by use of e-beam lithography and RIE techniques. High doses SOR experiments indicate an excellent long-term stability of SiC-W-masks.

Patent
10 Feb 1987
TL;DR: In this article, the pattern width of an adjoining edge part was made wider than other when the photomask having the display area divided at plural areas was reduced and projected onto the substrate.
Abstract: PURPOSE:To manufacture a liquid crystal display electrode substrate with a satisfactory yield by making the pattern width of an adjoining edge part wider than other, when the photomask having the display area divided at plural areas is reduced and projected onto the substrate. CONSTITUTION:A photomask 1 manufactured so that a gate bus pattern 2 and a display electrode pattern 3 can be positive pattern is successively reduced, projected and exposed on the substrate 6, and the pattern width of an edge 4 superposing each other with the adjoining mask is thicker than other. Consequently, the thinness of the thin part formed on the substrate of a double exposed overlapping part 7 is eliminated, the disconnection is prevented and the production yield can be improved.

Patent
25 Jun 1987
TL;DR: In this article, the problem of mask pattern transfer with high accuracy was addressed by providing slits each having an untransferrable width to the internal angle side of curved parts.
Abstract: PURPOSE:To permit the transfer of a mask pattern with high accuracy by providing slits each having an untransferrable width to the internal angle side of curved parts. CONSTITUTION:A photomask 21 is for forming the gate wiring pattern of a semiconductor device and is formed by forming a fine mask pattern 23 on a mask substrate 22 consisting of a transparent glass plate, etc. The mask pattern 23 is formed of a light shieldable film such as chromium oxide film and is provided with the slits 24 at the internal angle theta 21 (<180 deg.) of the curved parts thereof. The slits 24 are set at such a width (for example, <=0.5mum) which are not resolved at the exposing (irradiation) wavelength of an exposing device. Each slit 24 is disposed in such a position where one end thereof exists at the peak part of the internal angle theta 21 and the other end exists near the external angle theta 22 opposite to the peak part of the internal angle and where the curved part is parted to two patterns by the slits 24.

Patent
07 Oct 1987
TL;DR: In this article, the authors proposed a photomask blank consisting of synthetic quartz glass, the thin film light shielding layer 13 which is stuck onto the surface of the substrate 12 and consists of molybdenum silicide and the thin-film antireflection layer 14 which is attached to the substrate by a needle.
Abstract: PURPOSE:To prevent an increase of the thickness of a thin film antireflection layer by providing a thin film light shielding layer consisting of a high refractive index material and the thin film antireflection layer which is directly stuck onto the surface of the light shielding layer and consists essentially of tantalum oxide or tantalum nitride or the mixture composed thereof to the titled photomask. CONSTITUTION:A photomask blank 11 consists of a substrate 12 consisting of synthetic quartz glass, the thin film light shielding layer 13 which is stuck onto the surface of the substrate 12 and consists of molybdenum silicide and the thin film antireflection layer 14 which is stuck onto the surface of the thin film light shielding layer 13 and consists essentially of the tantalum oxide and tantalum nitride. The molybdenum silicide is the high refractive index material and the thin film antireflection layer 14 essentially consisting of the tantalum oxide and tantalum nitride has high resistance to acids and alkalis and high refractive index. The photomask which has the excellent optical characteristics, dry etching property and resistance to acids and alkalis and has consequently the high accuracy of pattern transfer at the time of photolithography is thus obtd. while the undesirable increase of the thickness of the thin film antireflection layer 14 is suppressed.

Patent
16 Sep 1987
TL;DR: In this paper, a photomask blank with the resist is immersed in the resist stripping liquid in a resist stripping device to strip the resist while ultrasonic waves are propagated therein for 3min.
Abstract: PURPOSE:To make effective use of a photomask blank by providing a stage for stripping the resist coated on the light shieldable film of the photomask blank by a resist stripping liquid, stage for removing the resist stripping liquid and stage for freshly coating the resist on the light shieldable film. CONSTITUTION:The photomask blank with the resist is immersed in the resist stripping liquid in a resist stripping device to strip the resist while ultrasonic waves are propagated therein for 3min. The photomask blank is then successively immersed into the cleaning liquids which consists of an isopropyl alcohol and the housed in 3 pieces of cleaning tank. The photomask blank is subjected to 1min of ultrasonic cleaning respectively in said tanks, by which the resist stripping liquid is removed from the light shieldable film and the photomask blank is dried. The resist stripping liquid and cleaning liquid are thus thoroughly removed. The resist is freshly coated by a known spin coating method on the light shieldable film of such clean photomask blank. The film thickness is inspected, and if the film thickness is of a desired value, the photomask blank is subjected to stages for exposing, developing, etching of the light shieldable film, etc., which are post stages, by which the photomask is manufactured.

Proceedings ArticleDOI
Katsumi Suzuki1
30 Jun 1987
TL;DR: In this article, a novel X-ray mask fabrication process, which is as simple as that used for conventional photomasks, has been developed, and masks with SIN, membranes which are stretched over rectangular rigid Si-frames, are fabricated from the same large wafer.
Abstract: A novel X-ray mask fabrication process, which is as simple as that used for conventional photomasks, has been developed. Several step and repeat X-ray lithography masks with SIN, membranes, which are stretched over rectangular rigid Si-frames, are fabricated from the same large wafer. Transparent window formations fot several tens of X-ray mask substrates are carried out simultaneously, by etching the (100) oriented Si wafers in KOH solution using no protection. V-grooves with (111) plane side walls, for dividing individual wafers into individual X-ray mask substrates, are simultaneously formed by the unisotropic etching. X-ray absorber patterns are fabricated on the SiNv membrane with rf-sputtered tungsten, by the subtractive method. Employing the present method, SIN, mask blanks, with less than 0.3μm warpage across a 26mm square window, have been fabricat&I with several tens of times higher throughput than can be achieved by the conventional process.

Patent
26 Sep 1987
TL;DR: In this article, a selective etching using no photoresist was performed by a method wherein plasma is generated by applying an electric field on halogenated hydrocarbon, and after polymer has been formed, the polymer is decomposed and removed on irradiation of a substrate with high energy rays.
Abstract: PURPOSE:To perform a selective etching using no photoresist by a method wherein plasma is generated by applying an electric field on halogenated hydrocarbon, and after polymer has been formed, the polymer is decomposed and removed on irradiation of a substrate with high energy rays CONSTITUTION:An Si substrate 1 is placed in the CHF3 atmosphere of 03Torr, and grown polymer 3 is deposited on the SiO2 layer 2 which is formed in deposition on the surface of the substrate 1 A photomask 4 is placed on the position away from said substrate, and the substrate is irradiated with an excimen laser beam through the photomask 4 As the laser beam is not transmitted on the light-shielding part of the photomask, the deposition of the polymer makes progress, but the laser beam is transmitted on the transparent part, and an SiO2, layer 2 is exposed by decomposing the polymer deposted on the substrate As a result, the SiO2 layer 2 is etched by the F in the plasma

Patent
17 Apr 1987
TL;DR: In this article, a photomask having a defect to be corrected is arranged, and a vacuum degree specified beforehand is kept in the vacuum container 12, and the position where a laser beam 5 is irradiated corresponds to the pin hole 3, a fine area 6 is irradized so that the irradiating scope can be the same size as the pinhole 3, the beam diameter of the laser beam 3 is adjusted and the pin holes 3 is irradoured.
Abstract: PURPOSE:To decrease the occurrence of separation of a correcting part by irradiating a laser beam or electronic beam to a defective part to be corrected on a photomask in the mixed gas atmosphere with metallic compound gas and carbon compound gas, forming silicon carbide at the defective part and filling the defective part. CONSTITUTION:In a vacuum container 12, a photomask 10 having a defect to be corrected is arranged, and a vacuum degree specified beforehand is kept in the vacuum container 12. Next, by using the stage system, the laser beam irradiating position of a laser beam generating source 4 is almost opposite to a pin hole 3 to be corrected for the photomask, and the silane gas and the carbon dioxide gas are introduced into the vacuum container 12. The position, where a laser beam 5 is irradiated, corresponds to the pin hole 3, a fine area 6 is irradiated so that the irradiating scope can be the same size as the pin hole 3, the beam diameter of the laser beam 5 is adjusted and the pin hole 3 is irradiated. A silicon carbide SiC is formed and accumulated to the pin hole 3, the pin hole 3 is filled by a silicon carbide 13 and comes to be transparent. Thus, without worry about the peeling off of the defect correcting part, correction can be executed without fail.

Proceedings ArticleDOI
30 Jun 1987
TL;DR: In this article, a new interferometric optical-heterodyne method has been developed for detection of displacement between a mask and a wafer using three symmetrically-arranged gratings and detects the displacement from the phases of beat signals using a 076-μm-period grating system and a He-Ne transverse-mode Zeeman laser.
Abstract: A new interferometric optical-heterodyne method has been developed for detection of displacement between a mask and a wafer This method uses three symmetrically-arranged gratings and detects the displacement from the phases of beat signals Using a 076-μm-period-grating system and a He-Ne transverse-mode Zeeman laser( wave length = 06328 μm ), sensitivity better than 1° /001 μm was obtained and displacement smaller than 5nm was detected independently of the mask-wafer gap variations With this method, a prototype alignment system having vertical mask and wafer stages was constructed for synchrotron x-ray lithography The alignment accuracy better than 001 μm was achieved Effects of several factors ( dimension of grating, resist coating, etc ) influencing the alignment accuracy are discussed

Patent
30 May 1987
TL;DR: In this paper, a pair of foam generating parts facing each other to the inside of a cleaning tank in which a detergent such as org. solvent or pure water is filled is used to remove the deposit on the surface of a photomask.
Abstract: PURPOSE:To remove the deposit on the surface of a photomask by providing a pair of foam generating parts facing each other to the inside of a cleaning tank in which a detergent such as org. solvent or pure water is filled. CONSTITUTION:Foam groups 7 are ejected from the fine pores of the foam generating parts 6 in the cleaning tank 4 to which the detergent 5 is supplied from an inlet 8 at a prescribed flow rate by the high-pressure air forced into the foam generating parts 6. A mask holder 3 is then moved upward or down ward by which the photomask 1 is immersed into the detergent 5. The foam groups 7 are then injected to the surface of the photomask 1. The collision energy of the foam groups 7 by the injection, the rupturing force of the foam groups 7 in the stage of collision and further the resistance on the surface with the detergent 5 by the vertical movement of the photomask 1 are thereby synergistically acted, by which the fine foreign matter sticking to the surface of the photomask 1 is efficiently removed.

Patent
25 Sep 1987
TL;DR: In this paper, a resist pattern is applied to the light shielding film, exposed and developed to form a resist patterns on the film and this film is selectively etched with a mixed aqueous soln.
Abstract: PURPOSE:To obtain a photomask whose substrate is free from invisible scratches and has small roughness on one principal surface on which the light shielding film is not present by using a specified soln. when a light shielding film on a substrate is selectively etched. CONSTITUTION:One principal surface of a transparent substrate of quartz glass or the like is coated with a light shielding film to form a photomask substrate. A resist is applied to the light shielding film, exposed and developed to form a resist pattern on the film and this film is selectively etched with a mixed aqueous soln. contg. one or more among ammonium hydrogenfluoride, ammonium fluoride, hydrosilicofluoric acid and fluoboric acid and hydrogen peroxide and/or nitric acid. The resist pattern is then stripped off to obtain a desired photomask.

Patent
02 Apr 1987
TL;DR: In this article, a positive type photoresist is applied on a substrate formed with the existing pattern consisting of a material having a reflectivity higher than the reflectivity of the substrate, exposing said resist and utilizing a difference in reflectivity.
Abstract: PURPOSE:To permit reproduction of the same pattern on an existing pattern without using a photomask and without requiring alignment by coating a positive type photoresist on a substrate formed with the existing pattern consisting of a material having the reflectivity higher than the reflectivity of the substrate, exposing said resist and utilizing a difference in the reflectivity. CONSTITUTION:The positive type photoresist 4 is coated on the substrate having the existing pattern 1 consisting of the high refractive index material such as metallic film. The entire surface of the resist is thereafter exposed without using the photomask. The exposing is progressed faster in the resist on the existing pattern 1 consisting of the high refractive index material than in the resist on the substrate 2 by the difference in the reflection of the light. The resist on the existing pattern is, therefore, removed by projecting min. required light energy thereto, while the resist on the substrate 2 remains. The negative resist pattern 8 of the existing pattern 1 is thus obtd. The film 3 which is the 2nd layer is then formed thereon and is patterned by a lift off method using the resist pattern 8, by which the same pattern is completed on the existing pattern.

Patent
18 Jun 1987
TL;DR: In this paper, a dummy pattern 30 is provided at the position corresponding to the end part of lower wiring where reflected light from the slanting surface on the end parts exerts influence upon an electrode wiring pattern during photoengraving.
Abstract: PURPOSE:To prevent electrode wiring from becoming thin and being broken by providing a dummy light shield pattern of size smaller than the resolution limit size of an exposing device in an area where a light transmission area is limited. CONSTITUTION:A photomask 1 used for a photoengraving method has the dummy pattern of size smaller than the resolution limit size of the exposing device in its light transmission area 3 at a position corresponding to a lower wiring end part. This dummy pattern 30 is provided at the position corresponding to the end part of lower wiring where reflected light from the slanting surface on the end part exerts influence upon an electrode wiring pattern during photoengraving. Therefore, a photoresist film 10 on the lower wiring end part is exposed and no photoresist pattern is formed at the position. The light, however, is weakened in intensity as compared with ultraviolet light which is transmitted through the light transmission area 3 of the photomask 1 where the dummy pattern 30 is not present and reaches the photoresist film 10. Consequently, the metallic electrode wiring which neither becomes thinner nor has a break is formed closely to the lower wiring.

Patent
10 Mar 1987
TL;DR: In this article, a method is proposed to minimize any measurement errors by a method wherein, after spot-exposing an inspected region arbitrarily selected on a semiconductor substrate, a chip pattern is aligned, exposed and developed to expose the inspected region and then the substrate is inspected on the exposed part.
Abstract: PURPOSE:To minimize any measurement errors by a method wherein, after spot-exposing an inspected region arbitrarily selected on a semiconductor substrate, a chip pattern is aligned, exposed and developed to expose the semiconductor substrate in the inspected region and then the semiconductor substrate is inspected on the exposed part CONSTITUTION:Prior to the alignment process, a product wafer is spot-exposed to be followed by normal lithography process so that the thickness of film coating a substrate 1 and the dust stuck thereon may be inspected assuming the spot-exposed region to be the inspected region The light passing through a glass fiber is applicable to the spot exposure The substrate 1 is coated with photoresist by a coater 21; a photomask is aligned and exposed by a spot exposer 22 with its fiber end set on an arbitrary spot on a wafer as well as an aligner 23 to be developed by a developer 24; finally the inspected region 2 and a chip pattern are formed in photoresist Through these procedures, any measurement errors can be minimized

Patent
25 Mar 1987
TL;DR: In this paper, the authors proposed to prevent the interference of a light beam for exposing by interposing an antireflection film between a mask substrate and a transfer pattern, where the transfer pattern exists and a metallic film consisting of, for example, Cr, Ni, Ta, etc.
Abstract: PURPOSE:To prevent the interference of a light beam for exposing by interposing an antireflection film between a mask substrate and transfer pattern. CONSTITUTION:The transparent film 2 which acts to prevent the reflection of the light beam for exposing is provided at the boundary face 4 on the side of a glass mask 1 of quartz, etc. where the transfer pattern exists and a metallic film consisting of, for example, Cr, Ni, Ta, etc. is formed on the film 2. The pattern 3 for guide tracks and address parts is formed to the metallic film. Such constitution and mask producing means which prevent the etching of the film 2 are used in the stage of etching the film 3. The interference of the light for exposing in a gap is eliminated even if such gap exists between the photomask and the resist film coated thereon. The satisfactory transfer of the pattern for the guide tracks, etc. is thus made possible.