Showing papers on "Resist published in 1969"

Electron Resists for Microcircuit and Mask Production

Abstract: The properties of poly‐(methyl methacrylate), a new electron resist developed at IBM Research, are presented in comparison to commercial photoresists under electron beam exposure. It is shown that methacrylate resist, with suitable processing, presents a means for submicron device fabrication with reasonable speed. Transistors with one‐ and half‐micron emitter stripe widths have been fabricated using this resist as a medium for diffusion masking with . Also, a method for producing high‐resolution, defect‐free masks through methacrylate resist is presented.

Polymeric Electron Beam Resists

Abstract: Crosslinking polymers may be used as negative acting resists. The product of the minimum charge dose required and the weight average molecular weight is a constant and is a characteristic of the polymer. At an electron beam voltage of 10 kV, this Q‐M product is found experimentally to be 6.3 coul‐g/cm2‐mole for polystyrene, 1 coul‐g/cm2‐mole for poly (vinyl chloride), and 14 coul‐g/cm2‐mole for polyacrylamide. Degrading polymers may be used as positive acting resists. Their average molecular weights have only a very minor effect on their efficiency as positive resists. Their glass transition temperatures are an important factor. It is recommended that these resists be prebaked at , stored and developed at , and postbaked at .

Electron beam fabrication system and process for use thereof

Abstract: A SYSTEM FOR FABRICATION OF PATTERNS IS SUBSTRATES SUCH AS INTERGRATED CIRCUITS ON SILICON WAFERS, EMPLOYS A SCANNING ELECTRON MICROSCOPE TO PRODUCE A PHOTOCATHODE HAVING THE DESIRED SURFACE PATTERN THEREIN AND THE PHOTCATHODE IS THEN EMPLOYED TO PRODUCE REPLICATE PATTERNS ON A PLURALITY OF SUBSTRATES. THE PHOTOCATHODE PRODUCES A PATTERNED ELECTRON BEAM WHICH IMPINGES ON AN ELECTRON RESIST ON A SUBSTRATE TO PROVIDE FOR DIFFERENTIAL SOLUBILITY BETWEEN THE ELECTRON BEAM TTREATED ZND UNTREATED RESIST AREAS. REMOVING THE MORE SOLUBLE PORTION OF THE ELECTRON RESIST AFTER TREATMENT BY THE PHOTOCATHODE, EXPOSES THE SUBSTRATE SURFACE WHICH IS THEN ALTERED EITHER PHYSICALLY OR CHEMICALLY. ONE OR MORE HIGHLY PRECISE PATTERNS BOTH IN THEIR LOCATION AND CONFIGURATION, MAY BE PRODUCED ON THE SURFACE OF A SUBSTRATE BY APPLYING A SERIES OF SUCCESSIVE ELECTRON RESISTS TO THE SUBSTRATE AND USING A PLURALITY OF PHOTOCATHODES.

Process of producing plated through-hole printed circuit boards

Abstract: PLATED THROUGH-HOLE PRINTED CIRCUIT BOARDS ARE PRODUCED BY PRINTING A FIRST RESIST MATERIAL (I.E. PHOTORESIST) ONTO APPROPRIATE METAL-CLAD LAMINATE BOARD SURFACES IN A PATTERN PREDETERMINED BY THE DESIRED CIRCUITS AND THEN UNIFORMLY COATING ALL OF THE BOARD SURFACES WITH A SECOND RESIST MATERIAL (I.E. A NITROCELLULOSE LACQUER) AND PRODUCING DESIRED THROUGH-HOLES BETWEEN SELECTED AREAS OF THE COATED BOARD SURFACES. THEREAFTER A LAYER OF A FIRST METAL (I.E. CU) IS APPLIED ONTO THE THROUGH-HOLE WALLS AND ON THE COATED SURFACES BY A METAL-REDUCTION PROCESS AND SUCH METAL LAYER IS THEN REMOVED FROM ONLY THE COATED SURFACES AND A LAYER OF A SECOND METAL (I.E. AU) IS ELECTROPLATED ONTO METAL-RECEPTIVE HOLE WALLS AND/OR BOARD SURFACES. THEN THE SECOND RESIST MATERIAL IS REMOVED FROM THE BOARD SURFACES AND THEN PORTIONS OF THE METAL-CLAD ARE REMOVED FROM THE BOARD SURFACES IN A PATTERN PREDETERMINED BY THE DESIRED CIRCUITS. THE ELECTROPLATING CAN OCCUR BEFORE OR AFTER THE REMOVAL OF THE SECOND RESIST MATERIAL; WHEN OCCURRING BEFORE, THE SECOND METAL IS ELECTROPLATED ONLY ON THE COATED THROUGH-HOLE WALLS AND WHEN OCCURRING AFTER, THE SECOND METAL IS ELECTROPLATED ON THE COATED THROUGH-HOLE WALLS AND ON THE METAL-CLAD BOARD SURFACES FREE OF RESIST MATERIAL.

Multiple imaging charged particle beam exposure system

Abstract: An electron source illuminates a pattern mask having a desired aperture pattern therein. Electrons passing through the pattern mask impinge upon a mesh screen. A high-voltage electrical source is connected between the mesh screen and an electron-sensitive resist coated substrate to produce a strong electrical field therebetween. Each hole in the mesh screen acts as an electron lens for producing an image of the pattern mask on the electronsensitive resist, thus resulting in an array of exposed images on the electron-sensitive resist. Alternatively, an ion source may be used with an ion-sensitive resist coated substrate or ions may be implanted directly into a substrate.

Method of making a patterned metal film article

Abstract: A method of making a patterned metal film article comprising depositing an organic resist material on the surface of a relatively nonporous insulating substrate in the pattern desired for the metal, leaving portions of the substrate surface exposed, treating both the exposed substrate surface portions and the resist surface with a sensitizer and with an activator for electroless deposition of a metal on both these surfaces, treating both said surfaces with an etching solution so that only the exposed substrate surface portions become deactivated, and treating both the surfaces with an electroless metal plating solution such that metal deposits only on the resist surface.

Mold rocking mechanism in a continuous metal casting plant

Abstract: A mold-rocking mechanism installed in a continuous metal casting plant, comprises a system of pivotal links on which is mounted a frame carrying the mold. The link system includes links which resist only forces directed along their axes and these links are attached to the frame and to the framework of the plant by means of flexible members.

Chemical machining process

Abstract: A process for chemically machining metals, particularly steels and steel alloys, to depths greater than 0.010 inches by using a chemical etching solution. The metal is coated with an etch-resist, exposed to an energy source to harden and bond a predetermined area of the resist to the metal and then developed to remove the unhardened and unbonded resist. The metal is then recoated with resist, again exposed to an energy source to harden and bond the second resist layer to the first resist layer at the aforesaid predetermined area and then developed to remove the unhardened and unbonded resist. The metal is then passed through a chemical etching solution to chemically machine those areas of the metal unprotected by the double layer of resist.

Photoresist Materials and Applications

Abstract: Photoresists can be classified as either positive resists or negative resists depending on their mode of interaction with light. With the exception of photomasking, the process handling considerations for these two classes are similar. Photoresist performance is highly dependent on processing techniques. Typical processing procedures are discussed along with process problems and performance limitations of currently available materials. General materials chemistry of typical photoresists is discussed, and possible photomechanisms, development mechanisms, and adhesion mechanisms are considered. Substrates to which a resist is applied introduce another variable for consideration when evaluating resist performance.

Method of etching cu with use of pb and sn layers as a mask

Abstract: A PROCESS FOR PLATING A CUPREOUS SURFACE COMPRISING FIRST PLATING SAID SURFACE WITH IMMERSION LEAD AND THEREAFTER PLATING WITH IMMERSION TIN. THE PROCESS IS PARTICULARLY APPLICABLE TO THE FORMATION OF PRINTED CIRCUIT BOARDS WHERE THE STEPS WOULD COMPRISE APPLYING A NEGATIVE PLATING RESIST IN AN IMAGE PATTERN OVER AN INSULATING SUBSTRATE HAVING A SURFACE OF CUPREOUS METAL, THE EXPOSED AREA OF SAID METAL NOT COVERED BY THE RESIST DEFINING A DESIRED CONDUCTOR PATTERN, PROVIDING A LEAD COATING OVER THE EXPOSED METAL BY IMMERSION PLATING, PROVIDING AN IMMERSION PLATING OF TIN OVER THE LEAD, REMOVING THE PLATING RESIST AND ETCHING METAL EXPOSED BE REMOVAL OF THE PLATING RESIST.

Tin solder coated with chromium as a mask for etching a metal base

Abstract: A METHOD OF ETCHING A METAL WORKPIECE IS DESCRIBED, WHICH CARRIES A TIN RESIST (OR A TIN-COATED SOLDER RESIST), A CHROMATE COATING IS PROVIDED OVER THE RESIST, AND THE METAL WORKPIECE IS ETCHED WITH AN AQUEOUS ETCHANT SUCH AS A PEROXYSULFATE CONTAINING PHOSPHORIC ACID OR A SODIUM CHLORITE-AMMONIUM HYDROXIDE SOLUTION OR A CHROMIC-SULFURIC ACID BATH TO DISSOLVE THE METAL FREE OF RESIST, THUS PRODUCING BRIGHT, SMOOTH AND ELECTRICALLY CLEAN RELIEFS HAVING SHARP PATTERN DEFINITION ON THE METAL WORKPIECE.

Mask for etching enlargement

Abstract: A mask has a metallic material, preferably cold-rolled steel, covered by an etchant-resist layer on both sides. On one side the layer has a circular area of diameter X2 void of etchant resist, and on the second side the layer has a circular area of diameter X3 and an annular area of outer diameter X1 both void of etchant resist. The three areas are coaxially aligned.

Improvements in or relating to the Formation of Electrically Insulating Layers.

Abstract: 1,165,565. Printed circuits. INTERNATIONAL COMPUTERS Ltd. 9 Oct., 1967 [29 Oct., 1966], No. 48583/66. Heading H1R. In a method of forming a patterned electrically insulating layer on a support (e.g. a substrate carrying a printed circuit) the support is first coated with a positive photo resist layer which is masked, exposed to light, and developed leaving a resist pattern e.g. stripes 8 (Fig. 5) on the support 1. An insulating layer 9 of polymer is then formed thereon in a vacuum chamber 10 (Fig. 7). Monomer vapour from a source 12 is introduced into the chamber and electrons from an electron gun 13 polymerize the monomer vapour to form the required layer 9. The support is then immersed in a solvent bath to remove the resist stripes lying beneath the polymer layer so that portions of the polymer layer deposited on the stripes fall away leaving stripes 2 (Fig. 1) of insulation. The solvent bath may be agitated ultrasonically (Fig. 8, not shown). If required electrically conductive layers (e.g. a layer of chromium and a layer of gold) having the same pattern as the polymer layer 9 and in alignment therewith may be formed thereover by vapour deposition in the vacuum chamber before dissolving the resist pattern in the solvent bath. The polymer may be dimethyl polysiloxane.

A Process for the Production of Electrical Thin-Layer Circuits

Abstract: 1,164,635. Thin film capacitors; printed circuits. KERAMISCHE WERKE HERMSDORF VEB. 14 Nov., 1966, No. 50919/66. Headings H1M and H1R. [Also in Division C7] In a process for producing a thin-film circuit on a glass substrate 1, conductors 2, 3, contact areas 4 ... 7, and a first capacitor electrode 8, are first formed by the vapour deposition in vacuo of an alloy comprising 50% Fe and 50% Ni at c. 300‹ C. Thereafter are deposited in succession a capacitor dielectric layer 9, e.g. SiO, a second capacitor electrode 10 of the same alloy as the first, and finally resistances 11, 12 and a monitor resistance 13, of Ni-Cr alloy. The latter alloy may also be applied as a solder resist to electrode 10, or some other resist may be applied. In a modification, after the deposition of conductive areas 2 ... 8, resistances 11 ... 13 are deposited and the device is then tempered, preferably in an oxygen-containing atmosphere, at 150-400‹ C. Next, dielectric layer 9 and electrode 10 are deposited. Conductive areas 2 ...7 are then tinned, as at 14, the oxide layer formed thereon during the tempering step being previously removed by a suitable fluxing agent, and electrode 10 again being protected, as by Ni-Cr alloy. During the deposition of the resistances 11, 12, their value is measured by monitoring resistance 13 which is deposited simultaneously. The production of a circuit comprising only resistors and conductors is also described. Substrate 1 may alternatively comprise ceramic or a synthetic resin.

Improved sandblast resist

Abstract: 1,148,092. Blasting. A. TARVIT. 15 Sept., 1966 [16 June, 1965], No. 25356/65. Heading B3D. A sandblast resist comprises a flexible sheet 2 of readily abradable material and a coating 3 of a resilient resist material applied to one surface of the sheet to leave uncoated areas representing the design it is desired to reproduce by sandblasting. The coating of resist material may be applied by printing, e.g. silk-screen printing. The flexible sheet may be paper; the resist material may be applied to the ungummed surface of a sheet of gummed paper. Colouring material may be added to the resist material to facilitate observation of the progress of sandblasting. Half tone effects can be obtained by using two resists in succession, the first exposing both the half and full tone areas while the second exposes only the full tone areas.

Improvements in or relating to electrical circuit structures

Abstract: 1,143,957. Printed circuits. INTERNATIONAL COMPUTERS Ltd. 5 July, 1966 [13 July, 1965], No. 29736/65. Heading H1R. A printed circuit comprises a first set of parallel conductors 8 formed by vacuum deposition, and a second set of parallel conductors 10 similarly deposited over the first set at right angles thereto, and insulated therefrom by interposed strips 9 of insulating material, desired connections between conductors of the two sets being effected at cross-over points by connecting links 15. As shown, power conductors 3 are formed on a sintered alumina ceramic substrate 1 by silk screening thereon a pattern of Au in a glass matrix, followed by firing. An insulating layer 4, having a matrix of rectangular apertures 5 therein, is formed by silk screening a glaze over substrate 1 and conductors 3, followed by firing. An earth plane 6 is next formed, by the same method as conductors 3, having apertures which register with apertures 5, and projections 7 which protrude into the apertures. A further insulating layer 18, similar to layer 4, is next deposited, and conductors 8 are formed on layer 18 by the vacuum deposition of Au through a mask. A layer of photo-resist is now applied followed by an evaporated Au layer and a second layer of photo-resist. The second layer of resist is exposed and developed to form a protective pattern over conductors 10; the rest of the Au layer is etched away, so uncovering the underlying first resist layer, which is exposed, developed, and removed except below conductors 10, where it remains to form insulating strips 9. Discontinuities 11 are produced where required in conductors 8, 10 by spark erosion, and conductive links 15, 16 between selected conductors 8 and 10 are formed by the vacuum deposition of A1 through a layer of photo-resist exposed at the site of each link to an electron beam and subsequently etched. Electrical components 2, such as integrated circuit chips, are positioned in apertures 5, contact areas on the components being ultrasonically welded to power conductors 3, earth plane projections 7, and areas 17 of conductors 8, 10 which project into apertures 5; either the contact areas or the circuit terminal areas may be plated with Al or Au to facilitate welding. Modifications.-The substrate 1 may be of glass, Si, or a conductive material such as Al coated with an insulating material such as alumina, SiO, or photo-resist. The components 2 may be inserted in recesses in the substrate, connection to the circuit being by vacuum deposition; or apertures in the substrate may be temporarily filled with wax during the formation of the conductors which are reinforced by electroplating, the wax being subsequently removed and replaced by the components which are connected into the circuit by welding or deposition of A1 links. Other noble metals may replace Au, and conductors 3, 8, 10 may be formed by the vacuum deposition of Cr or Ni-Cr followed by Au. Insulation layers 4, 18 may be of exposed, developed photo-resist, or a polymer, or SiO; and layer 18 may be formed of strips similar to strips 9. In place of spark erosion, discontinuities in the conductors mav be formed by electron beam or laser beam scanning, chemical etching, mechanical scribing, or condenser discharge.

Improvements in or relating to Capacitors.

Abstract: 1,170,991 Capacitors; printed circuits MINISTER OF TECHNOLOGY 19 April, 1968 [31 March, 1967], No 14842/67 Headings H1M and H1R A capacitor or cross-over comprises a first conductive layer 2 on a glass or ceramic layer 1, a first dielectric layer 3, a second dielectric layer 4 formed of a hardened photo-resist material, the material of the first dielectric layer 3 having a dielectric strength resistivity, and dielectric constant greater than those of the hardened photo-resist material The photo-resist material is preferably of the negative type having a dielectric constant of between 2 and 3 The first dielectric layer preferably has a dielectric constant of at least 7, eg aluminium oxide formed by anodizing a vapour deposited aluminium layer, a deposited silicon monoxide layer, or a polysiloxane formed in situ by electron bombardment in vacuum of a precursor After the resist layer is applied, the coated substrate is baked and the resist layer is exposed to uv radiation through a mask defining the desired shape of the dielectric layer The unexposed resist is removed using the appropriate developer, and the second conductive layer applied, eg by vacuum evaporation of aluminium through a stencil

Fabrication of integrated circuits using the electron image projection system (ELIPS)

Abstract: ELIPS is based on the use of an electron image tube principle to project large area (2" dia.) ultra high resolution (1 micron) images from a patterned photocathode onto an electron sensitive resist layer thereby replacing the conventional photoresist optical procedures in integrated circuit fabrication (1).