Showing papers on "Photomask published in 1978"

Plasma development process for photoresist

Abstract: After exposure to radiation photoresist may be developed by a dry process using a gas plasma, preferably an oxygen plasma. The process can be used for chemical milling, photolithography, printed circuit board and photomask manufacture and it is particularly advantageous in the manufacture of semiconductors. The plasma development process can be followed by plasma etch and strip processes without requiring removal of the work piece from the plasma reactor.

Photomask alignment system

Abstract: An automatic photomask alignment system includes a monochromatic light source, such as a laser, a series of diffraction patterns which are located on a semiconductor substrate and keys which are located on photomasks with which the substrate is to be aligned. A light beam is directed through the key on a photomask onto the diffraction pattern to provide a pattern of light spots whose intensities at various locations are determined by the relative alignment of the mask and the diffraction grating. A feedback arrangement which employs photocells and means for moving the photomasks relative to the substrate provides the alignment of the photomasks with the substrate.

Double master mask process for integrated circuit manufacture

Abstract: A double master mask process for fabricating semiconductor integrated circuits is provided in which selectively etchable dielectric layers and ion implanted resistors are used to form dense integrated circuits with a minimum number of critical alignments. A first silicon dioxide silicon nitride layer used in conjunction with a first master photomask defines a base region and an isolation region which are self-aligned with respect to each other and with respect to resistor contact regions. After isolation and base diffusion, the first oxide/nitride layer is stripped away and a second oxide/nitride layer is grown. Using a photoresist mask, a predeposition layer for the resistor is then formed using ion implantation through the oxide/nitride layers. A second master photomask allows the formation of collector and emitter regions and base and resistor contact which are self-aligned with respect to each other. The diffusion cycle used to form the collector contact and emitter regions simultaneously anneals the ion implanted resistor region to form a high value resistor of closely controlled tolerances. In conjunction with the use of the first master mask, a base region and isolation region which are self-aligned with respect to each other are formed through the use of a "base washout" process which maintains self-alignment without the use of additional process steps.

Method of repairing a defective photomask

Abstract: A method of repairing pin holes in a defective photomask such as one comprising a patterned chromium film on a glass substrate comprises depositing an adhesion promoting film such as siloxane on the surface of the photomask, then depositing a solvent soluble layer such as a photoresist layer over the adhesion promoting layer, a window is then formed through the layers and underlying photomask in the area of the pin hole by burning through these layers by means of a laser The exposed areas of the window are etched and a metallic film is deposited over the exposed surfaces Finally, the photomask is treated with solvent for removing the solvent soluble photoresist which also causes the metal film deposited thereon to be removed in all areas except the area of the window

Correcting method for defect of photomask

Abstract: PURPOSE:To correct defects by irradiating electron beam to the photomask light transmission part in the atmosphere where organic compound vapour exists.

Photomask substrate and photomask

Abstract: PURPOSE:To obtain a photomask whose durability and electron beam exposure adaptability are excellent by using a photomask substrate provided with thim the light-transmittable film of specified electrically conductive metal such as Mo on the transparent substrate, on which it has the light-shielding thin film of specific metallic oxide. CONSTITUTION:On a transparent substrate 1, an electrically conductive thin film 4 in 1-100mum thickness and having >=60% transmissibility against the light in 200- 550nm wavelength selected from a group of Mo, Nb, Ta, Ti, V, W and Zr, and plane resistance is formed by a sputtering method. Then, on the film 4, light shielding material 2 selected from a group of metallic chromium, chromium oxide, metallic silicon, iron oxide is laminated and a light-shielding thin film 2 patterned by using a resist film is left. Next, when the resists film 3 is removed, a mask of excellent durability can be obtained on the substrate and it has high surface hardness, corrosion resistance, close contact between the substrate 1 and the light shielding film 2 and does not cause peeling off or breaking off of the film 2 due to discharging phenomenon on stripping off after the mask and a semiconductor substrate are brought into close contact with each other.

Manufacture of photomask

Abstract: PURPOSE: To reduce the number of processes or steps and labor, by making, inspecting and correcting a pattern in one process by a single unit for manufacturing a photomask. CONSTITUTION: Electronic lenses 6W8 are driven by a lens power supply unit 9, which is controlled by a scanning controller 10. A prescribed pattern is made on a mask 15 in accordance with information supplied from a pattern memory 13 through a central controller 12. The mask 15 provided with the pattern is scanned by an electron beam of energy smaller than that for making the pattern so that a secondary electron image of the pattern is obtained by a detector 11. A pattern signal from the detector 11 is compared with that from the memory 13 by the controller 12. A detective pattern portion, which does not coincide with the pattern stored in the memory 13, is stored into a defect storage region 20 of the memory. After inspection, a defective part due to the shortage of electron irradiation is patterned again in the same way as the initial patterning, thereby correcting the mask pattern. COPYRIGHT: (C)1980,JPO&Japio

Plate for photomask

Abstract: PURPOSE:A reflection preventive film is provided in the light trnasmission part of a shading film, ahd therefore, light interference is prevented, thereby obtaining a pattern of a high precision.

Photomask cleaning method

Abstract: PURPOSE:To remove the deposits containing the resist deposited on a photo mask by causing them to make chemical reaction with an active gas.

The properties of X-bar bubble memory chips

Abstract: The properties of a 16-kbit bubble memory chip having a conventional major-minor loop organization are described. The chip can be operated up to a shift rate of 300 kHz which corresponds to a mean access time of 0.5 ms to blocks of 128 bits. Overall bias field margins of 13 percent were obtained, especially as the result of an appropriately selected layout of the transfer gates which is described in detail. Additional data are given concerning the influence of ambient temperature and of the number of propagation steps. The possibility of fabricating X-bar transfer gates using a single photomask step is demonstrated.

Photomask for photomechanics

Abstract: PURPOSE:To enhance a production efficiency by giving the best arrangement type of element chip groups to the arrangement shape of photomask chip groups for photomechanical process

Production of semiconductor device

Abstract: PURPOSE:To obtain a graft base transistor of a good high-frequency characteristic by forming the emitter and base contact forming windows simultaneously and setting the distance according to the pattern dimension precision of a photomask used at this time.

An Economical Photomask Processing Scheme for the Small Laboratory

Abstract: A system for the rapid and economical production of small quantities of precision masks for photolithography is outlined. The techniques described are especially suited to the wide range of device designs encountered in the small research or teaching laboratory.