Showing papers on "Photomask published in 1985"

Laser-based system for the total repair of photomasks

Abstract: An apparatus for repairing both clear and opaque defects in a photomask having a metal film pattern on a glass plate in which a visible laser light source is pulsed at selected frequencies to direct an optically focused laser beam into a gas sealed cell containing a mask. At one frequency, the laser pulses ablate opaque mask defects. At another frequency, and with the cell filled with a metal bearing gas, the laser beam causes thermal decomposition of the gas and deposition of metal to cure clear defects.

Process of transfer of mask pattern onto substrate and apparatus for alignment therebetween

Abstract: In an exposure apparatus for manufacturing semiconductor devices, a pattern on a photomask is aligned with a plurality of patterns formed on a wafer in a manner that detects and corrects misalignment, including, inter alia, rotational errors, not only between a photomask and a wafer, but also between a photomask and individual chips formed on the wafer, so that pattern matching is attained with very high accuracy. Apparatus for achieving this result employs different arrangements of alignment marks together with optical systems and positional adjustment devices.

Method of and apparatus for adsorbingly fixing a body

Abstract: A method of and an apparatus for adsorbingly fixing a body, such as a photomask (mask) or a wafer to a chuck, effect a preliminary vacuum-adsorbing step of preventing the creation of internal stress due to the temperature change between the body and the chuck before the final vacuum adsorption is effected, or effect a preliminary vacuum releasing step for relieving the created internal stress.

Film thickness measuring device and method

Abstract: Apparatus and a method are disclosed for measuring the thickness of a very thin transparent film formed, for example, on a photomask or wafer for an integrated circuit Diffracted reflected light from a film specimen is converted photoelectrically by use of a one dimensional image sensor array and then by an A/D converter having a resolution of more than 2 10 , which allows for discrimination into 1,000 graduations of output level Enhanced precision in determining film thickness is obtained by utilizing this high discrimination to first determine the variations among individual elements of the one dimensional sensor array and compensating for them, as well as by using known averaging and statistical techniques to generate output for comparison to reference data from film specimens of known thickness

Photomask and exposure apparatus using the same

Abstract: A photomask includes a pattern region including a predetermined original image pattern, a pair of mark regions which respectively include alignment marks located on a line crossing the pattern region and which are located at two sides of the pattern region, and a pair of light-shielding regions each of which has at least the same width as that of a corresponding one of the mark regions along a direction parallel to the line. An exposure apparatus for sequentially exposing a plurality of regions on a photosensitive substrate by using a projection image on the photomask includes means for moving the photosensitive substrate and the photomask relative to each other such that images of marks for a current projection image are projected on a portion of a nonexposed region of a previous projection image, the portion being located next to a previous mark latent image and the nonexposed region being located between the latent image of the previous original image pattern and the latent image of the previous mark.

Method of aligning a semiconductor substrate and a photomask

Abstract: This specification discloses an alignment method for aligning a photomask with a substrate covered with a photosensitive layer and printing the pattern of the photomask on the substrate. The method comprises the steps of providing a reference mark on the photomask, providing on the substrate a pair of alignment marks correlated to the reference mark, the pair of alignment marks being spaced apart from each other by a predetermined distance in a mark area, one of the pair of alignment marks being formed projectedly relative to the surroundings thereof and the other alignment mark being formed as a depression relative to the surroundings thereof, providing the photosensitive layer on the substrate so that the outermost surface of the layer is substantially flat, and imaging the reference mark and the pair of alignment marks superposedly on an imaging plane by a light having a single wavelength. The specification also discloses a photomask and an apparatus for executing such method.

Photomask and method of fabrication thereof

Abstract: A photolithographic mask for use in the fabrication of semiconductor integrated circuit devices, comprising a transparent substrate having a major surface, and a metallic film formed on the major surface of the transparent substrate and impermeable to ultraviolet rays having wavelengths within a predetermined range, wherein the metallic film is doped with sulfur ions to provide a reduced angle of contact between the surface of the film and a body of pure water to achieve an increased degree of adaptability of the photomask to cleaning with pure water when the photomask is put to repeated use over a prolonged period of time.

A Holographic Photomask Defect Inspection System

Abstract: The need for automatic defect inspection of photomasks has been well recognized by the semiconductor manufacturing industry. Indeed, commercial equipment for this purpose has been available for many years. The method used in the commercial equipment is based on the point-by-point comparison of one die with an adjacent die or with the data base, in a serial fashion. As the minimum features of the production integrated circuit (IC) pattern approach micrometer and submicrometer dimensions and the pattern area increases to about 150 mm in diameter, the inspection time per photomask by this method becomes formidably long, sometimes hours. To reduce the inspection time, radically different inspection methods are clearly needed. One such method is based on an optical information processing technique.1'2 This method has an inherent advantage: the IC pattern and the defect information over the entire photomask are processed simultaneously, or in parallel. However, several difficulties in the past have prevented this method from being practical. Under the sponsorship of Insystems, scientists at the University of Daytsn Research Institute were able to circumvent these difficulties by means of holography.'. Based on the successful results achieved there, Insystems undertook the task of developing an automated photo-mask inspection system, the Model 8405. This system is designed for turn-key operation in IC manufacturing facilities. Major performance specifications of the system are listed below. . Acceptable photomask sizes: standard sizes or others up to 178 mm x 178 mm (7" x 7") . Acceptable photomask thicknesses: standard thicknesses or others up to 6.4 mm (0.25") with or without pellicle . Detectable defect sizes: 0.5 um or larger with or without pellicle . Automatic inspection time: 7 minutes or less for 100 mm x 100 mm photomasks . Hologram or filter production time: approximately 6 minutes . Defect report formats: include computer printout of defect map (indicating defect types, sizes and locations), video terminal displays of holographic defect image and corresponding microscope image The purpose of this paper is to describe this system and present some preliminary results.

Process for fabricating semiconductor components

Abstract: A process for the fabrication of semiconductor components and in particular a process in which the components are fabricated with a controlled spacing of etched channels The process is in particular utilized in fabricating a monolithic array of elements such as a pin diode array The process of the present invention combines the use of an anisotropic silicon etching process for the desired device geometries with a means of defining all device surface topology by substantially a single photomask thus eliminating critical mask alignment A second embodiment of the invention is also described employing fewer layers of deposition with a double photomask step

Processing, shipping and/or storage container for photomasks and/or wafers

Abstract: This invention pertains to a system for holding Photomasks and/or wafers in a clean environment during processing, shipment and/or storage. The apparatus of the invention comprises a processing holder that may be used for the internal processing of photomasks and/or wafers, as well as being used as the inner portion of a photomask and/or wafer shipping and storage container.

Method for repairing a photomask by laser-induced polymer degradation

Abstract: A method for repairing clear defects on a photomask. The method includes the steps of coating the photomask with a positive photoresist; exposing the photoresist to a laser beam for localized heating thereof to a temperature above 500° C. to darken or char the polymer; and removing the unexposed polymer from the photomask. The method may also include the intermediate step of heating the polymer to a temperature between 200° C. and 500° C. to brown the polymer before the polymer is exposed to the laser which heats it to a temperature above 500° C.

Reticle used in semiconductor device fabrication and a method for inspecting a reticle pattern thereon

Abstract: A reticle used in a patterning process to fabricate a semiconductor device or a photomask, having a reference pattern consisting of reference pattern pieces, each having the same shape and size, the size being less than the resolution limit of a reduction exposure performed in the patterning process. The reference pattern pieces are extensively printed in an actual pattern region being for a semiconductor die on a reticle substrate with a reticle pattern, so that the reference pattern pieces are used for inspecting the reticle pattern but do not influence the printed pattern of the reticle pattern on a substrate of the semiconductor device or the photomask. In the inspection of the reticle pattern, the reference pattern pieces are used to provide the detected reticle pattern data obtained from the reticle pattern by scanning, so as to be able to be compared with designed reticle pattern data, i.e., synchronizing detected reference signals obtained from the reference pattern pieces by scanning with reference signals obtained from the designed data of the reference pattern.

Photomask having a patterned carbon light-blocking coating

Abstract: A photomask for use in manufacturing integrated circuits is fabricated by coating a thin film of organic material, generally a solution of a thermally decomposable hydrocarbon, onto a glass plate and heating it in a reducing atmosphere to convert it into carbon. The carbon layer is masked and etched; for example, in an oxygen plasma, to produce the mask.

Pellicle mounting apparatus

Abstract: A pellicle mounting apparatus characterized by a pair of pellicle holder assemblies positioned on either side of a photomask holder assembly. A drive mechanism is coupled between the two pellicle holder assemblies to exert a simultaneous force on the two assemblies to drive them towards or away from the photomask holder assembly. An alignment assembly including a pair of telescopes are first aligned with pellicle holder assemblies, and then the photomask is adjusted to align it with the telescopes. Once the pellicle holder assemblies and photomask holder assembly are properly aligned, pellicles can be repeatedly and accurately attached to opposing sides of a series of photomasks.

Rotatable and translatable mounting mechanism for a specimen pattern in optical processing apparatus

Abstract: A translatable and rotatable mechanism is employed in optical processing apparatus for exposing a specimen pattern and inspecting light pattern or image developed from it. The mounting mechanism includes a plate that is rotatably mounted on a linear positioning table assembly. The plate includes a substrate arm and a camera arm that extend in opposite directions from the axis of rotation of the plate. The specimen pattern, such as a photomask, is positioned on the free end of the substrate arm, and a video camera is positioned on the free end of the camera arm. Whenever the plate is rotated to an exposure orientation, the photomask diffracts light rays emanating from a laser. The diffracted light rays interfere with a reference beam to form a hologram. Whenever the plate is rotated 180° to an inspection orientation, a reconstructed imate of the photomask appears at the location where the photomask was positioned during exposure. The video camera is positioned directly beneath the reconstructed image and scans it by the translational movement of the positioning table. A microscope is mounted to a stationary support and is positioned over the photomask. The video camera and the microscope observe corresponding regions of the image and the photomask, respectively, in synchronism for all translational movements of the plate.

Contacting method and apparatus in contact copying

Abstract: A contacting method comprises the steps of holding a photomask and a wafer at a predetermined interval, curving at least one of the photomask and the wafer so as to form a convexity relative to the other, and moving the photomask and the wafer relative to each other to bring them into intimate contact with each other.

A method for facilitating the alignment of a photomask with individual fields on the surfaces of a number of wafers

Abstract: Described is a method for facilitating the alignment of a photomask with individual fields on the surfaces of a number of wafers onto which fields the pattern of the photomask is to be imaged for projection printing, each of said number of wafers carrying an identical array of fields produced in at least one previous printing process. For this purpose it is possible to choose one out of the identical batch of wafers, measure the rotational adjustment necessary to bring each field into the correct direction in the horizontal plane and to use the measured value for an automatic rotational adjustment of all other wafers of the batch.

Mask protective film

Abstract: PURPOSE:To prevent a pattern formed on a mask base from being damaged at its part, especially, at its edge due to electrostatic discharge in peeling a protective film when the photomask is used, by incorporating a fine conductive power in the protective film of the photomask for use in fabrication of semiconductor integrated circuits, etc. CONSTITUTION:A pattern 12 of a thin metallic film of Cr or the like is formed on a glass base 11, and then, it is coated with a protective film 13 made of synthetic resin in order to prevent damage and pollution till it is used. A conductive fine powder of about 0.1mum particle diameter, such as iron oxide or carbon, is incorporated in said film 13. As a result, the obtained photomask can be use for semiconductor integrated circuit, etc., and its protective film is prevented from electrostatic charge. When the protective film 13 is peeled in order to use the photomask, a part of the pattern 2, especially at the edge can be prevented from being broken due to electrostatic discharge.

Variable wavelength optical alignment system

Abstract: A photomask/wafer alignment apparatus for achieving a high precision alignment of the wafer alignment mark and the photomask window at all stages of photomask patterning employs a variable wavelength light source the optical output frequency of which is selectively controllable, so as to optimize the signal-to-noise ratio of the wafer alignment mark and the photomask alignment window, either under operator control, or through an automatic feedback arrangement The system also includes a two-dimensional variable aperture plate inserted between the variable wavelength light source and the projection optics for the photomask This variable aperture plate provides the capability of control both bandwidth and coherence of the variable wavelength light beam emitted from the multi-color light source, thereby optimizing the signal-to-noise ratio of the imaged alignment mark To maintain a sharp focus of the imaged mark, an adjustable correction lens is inserted in the imaging path between the wafer and the projections/return optics, so as to compensate for changes in focus due to changes in wavelength of the imaging beam

Photomask carrier and container for photomask carrier

Abstract: An injection-molded photomask carrier includes a base with a round opening of sufficient size and shape to permit light to pass through during a photolithographic process; at least three wall members joined to, upstanding from and framing the periphery of the base to support the edges of a photomask or a photomask/pellicle array resting on the base; a flange projecting inwardly from one of the walls, and a clip on the side of the base opposite the flange for movable engagement with the portions of the photomask or photomask/pellicle combination at its edges A container for the carrier is complementary in size and shape to the carrier, injection-molded, and includes an injection-molded cover for the container

Production of photomask

Abstract: PURPOSE:To manufacture a photomask without using a photoresist process by implanting selectively metallic ions into a metallic layer and changing the etching rate. CONSTITUTION:The metallic layer 2 of a transparent base plate 1 consisting of glass, etc. is subjected to ion implantation by irradiating selectively tungsten ion to said layer with an ion ray exposing device. If the ion kind and ion quantity to be implanted are adequately selected, the etching rate in the implanted part can be made considerably larger than the metallic part where the ion is not implanted in the next etching stage of the layer 2 by plasma. The etching rate by, for example, the gaseous plasma of carbon tetrachloride of the chromium oxide layer where the tungsten ion is not implanted is 200Angstrom /min and the part where the ion is implanted is unetchable. Only the pattern subjected to the ion implantation remains consequently when the dry etching is performed. The photomask is thus manufactered.

An approach to fabricating sub‐half‐micrometer‐length gates for GaAs metal‐semiconductor field‐effect transistors

Abstract: A process for fabricating sub‐half‐micrometer‐length gates for GaAs MESFETs is described. This process, which uses conventional photolithography, incorporates a number of special techniques to produce the gates from a photomask having 1‐μm‐length gate patterns. Gates produced by this process have shapes and cross‐sectional areas that are comparable to those of gates produced by liftoff using sub‐half‐micrometer electron‐beam lithography. Gates with lengths less than 0.2 μm have been fabricated.

Mask for semiconductor device

Abstract: PURPOSE:To know the directivity of a mask easily and to improve operation efficiency by cutting four corners of a square mask at 1-3 positions and forming chamfered parts. CONSTITUTION:A photomask consists of a device pattern part 1, chromium film 2, identification part 3 for the kind of the substrate, mask name part 4, chamfered parts 5, etc. The photomask is formed by patterning, for example, a glass surface by using a pattern material made of chromium. In this case, up to three chamfered parts 5 may be formed when necessary. The size of chamfering is preferably 3-10cm , but may be increased without reaching the device pattern part 1.

Electron beam exposure

Abstract: PURPOSE:To facilitate a formation of a photomask with a high accuracy by a method wherein a monitoring pattern is provided in each chip of an exposed part of a photomask, a wafer and the like in addition to a regular original pattern in order to check an accuracy of an electron beam equipment. CONSTITUTION:A monitoring pattern 10 is composed of patterns with which a scanning width W, an accuracy of a joint part of a stripe 4 and an accuracy of a beam are checked. An electron beam exposure of each stripe pattern 4 is performed in such a manner that the monitoring pattern 10 is exposed and scanned on one side and the original pattern is exposed and scanned and each chip of the whole surface of the photomask 1 is exposed along X-axis direction. Then the top pattern of the monitoring pattern 10 is drawn and the original pattern is exposed. The drawing of the monitoring pattern 10 and the exposure of the original pattern are repeated for every chip 2 and the exposure of the whole surface of the photomask 1 is completed. The accuracy of the joint part can be confirmed all over the photomask 1. The accuracy in the stripe 4 and a deflecting condition of an electron beam are also checked.

Photomask automatic defect inspection device

Abstract: PURPOSE:To improve the reliability of inspection by employing a photomask comprising a false defect pattern which is preset in advance so as to adjust an automatic defect inspection device in the optimum state. CONSTITUTION:A pattern of a photomask 1 is exposed onto a dummy wafer 11 and after transfer the pattern, the wafer is put on a movable table 12 and chip patterns 2 and 3 are detected and recognized by detection optical systems 13, 14 facing to each other and a detection circuit 15. The obtained electric signals are compared with a threshold value Vth in a comparison circuit 21 thereby detecting false defects. Then the chip patterns 2 and 3 are compared mutually in the contrast circuit 22 so as to recognize respective false defects 8 and 9 and that an automatic defect inspection device 10 is adjusted correctly is displayed by a display 25. If the false defect 8 or 9 is not detected in the comparison circuit 21, a slice level adjustor 23 operates to do the detection in the comparison circuit 21 again while changing the threshold value Vth gradually.

Analysis Of Linewidth Measurement Techniques For The Purpose Of Automation

Abstract: A model is described for the formation of diffraction-limited optical images of chrome on glass photomasks using an optical microscope. The effect of the imaging transducer is also considered, and a Gaussian model for a television camera is presented. National photomask calibration standards were examined using bright- and dark-field illumination, and the results are compared with the images predicted by the models. From the results it is concluded that the physical edge and the material properties of the chrome coating cannot be ignored when making precise linewidth measurements on photomasks. A dark-ground measurement technique is described that makes use of the physical edge of the chrome in order to determine linewidths. It is demonstrated how this technique may be used with bright-field illumination in order to measure linewidths on semiconductor wafers precisely. Both the photomask and wafer linewidth measurements may be automated, and a method of adopting the technique for automation is described.

System for aligning unexposed printed-circuit board blanks and photomasks with respect to one another

Abstract: System for aligning unexposed printed-circuit board blanks 10 and photomasks 1, 2 with respect to one another in the production of single- and multi-layer printed-circuit boards, comprising positioning aids which are disposed at the edge of the photomasks and of the printed-circuit boards respectively, and are assigned to one another which, in the printed-circuit board, have the form of positioning holes 12, a photomask lying on the printed-circuit board blank on one or both sides, characterised in that, the positioning aids at the edge of the photomask(s) have the form of opaque marks 6, 8 which are part of the mask pattern, a light source directs essentially parallel light perpendicularly at the composite comprising the printed-circuit board blank 10 and photomask(s) 1, 2, and through the positioning bores 12, which act as a diaphragm, over the marks, and that on the side of the composite facing away from the light source there is disposed, in the range of each positioning bore, an electronic line scan camera 14 in the beam path of the transmitted residual light, which camera is provided with an analysis circuit for determining the position of the shadow of the mark(s) 6, 8 with respect to the positioning holes.

Production for optical formed article

Abstract: PURPOSE:To present a producing method of an optical formed article which has not the loss of connection to an optical fiber when it is used as an optical waveguide and is easy to release when it is used as a printing plate, by making the mask density of a photo mask variable and rounding corner parts of an obtained optical formed article. CONSTITUTION:A photo mask 13 consists of shielding parts A, half-shielding parts B, and a non-shielding part C, and the density distribution of the mask 13 is as shown by a curve in figure. A method changing the thickness of the mask, a method changing the concentration of an emulsion, or the like is adopted as the method making the mask density variable. A photosensitive material 12 is exposed through this photomask 13 and is washed to produce the optical formed article, thus rounding corner parts.