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Showing papers on "Resist published in 1983"


Journal ArticleDOI
Hiroshi Ito1, C. Grant Willson1
TL;DR: In this article, a new resist system is described which undergoes spontaneous relief image formation, formulated from end capped poly(phthaladehyde), PPA, and a cationic photoinitiator such as a diaryliodonium or triarylsulfonium metal halide.
Abstract: A new resist system is described which undergoes spontaneous relief image formation. The resist is formulated from end capped poly(phthaladehyde), PPA, and a cationic photoinitiator such as a diaryliodonium or triarylsulfonium metal halide. The extreme sensitivity of the resist is the result of designing for chemical amplification. The desired amplification results from the fact that photolysis of the sensitizer generates acid which catalyzes main chain cleavage of the polyaldehyde. The uncapped polymer is thermodynamically unstable with respect to reversion to monomer at room temperature so a single acid catalyzed scission results in complete depolymerization to volatile monomer. A single radiochemical event is thereby amplified in the sense that it produces an enormous number of subsequent chemical transformations. PPA/onium salt resist films are so sensitive that exposure to low doses of e-beam, X-ray or ultraviolet radiation results in complete self development without post-exposure processing of any kind. The exposed area simply vaporizes.

394 citations


Patent
08 Feb 1983
TL;DR: In this paper, a thin oxide film is formed inside a window of a gate formed by selectively removing a thick oxide film formed on the surface of a substrate, an impurity is implanted from windows of a source and drain, a source region and a drain region are formed and the individual windows are filled with a conductor for electrode use.
Abstract: PURPOSE:To achieve a high-speed operation and a high integration density and to improve positional accuracy by a method wherein a thin oxide film is formed inside a window of a gate formed by selectively removing a thick oxide film formed on the surface of a substrate, an impurity is implanted from windows of a source and a drain, a source region and a drain region are formed and the individual windows are filled with a conductor for electrode use. CONSTITUTION:P regions 21 and 22 and an oxide film 23 are formed on a substrate 20; a source window, a drain window and a gate window 24, 25, 26 are formed; after that, a thin oxide film 27 is formed. Then, a photoresist 28 is formed selectively; ions of a Group V impurity are implanted; n-type impurity regions 29, 30 are formed. In addition, the implanted regions are driven and diffused deep; an n-type source region 31 and an n-type drain region 32 are formed. Then, a resist is formed selectively; the oxide film 27 on these is removed; after that, an aluminum layer 33 and a resist layer 34 are formed; these are etched. Then, the aluminum layer 33 is etched selectively by making use of the remaining resist layer 34 as a mask; the remaining resist layer 34 is removed; after that, an aluminum wiring part 35 is formed.

125 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of varying the laser wavelength has been examined and a simple model of ablative development has been used to predict the etch rate, and the processing stability of the resist has been increased without changing the optical development rate by adding a dopant.
Abstract: Nitrocellulose functions as a self‐developing photoresist which can be patterned using pulsed excimer laser radiation. The material exhibits a threshold fluence for ablation of 20 mJ/cm2 at a wavelength of 193 nm; this threshold results in higher contrast than can be obtained with most conventional photoresists. The effect of varying the laser wavelength has been examined. A simple model of ablative development has been used to predict the etch rate. The processing stability of the resist has been increased without changing the optical development rate by the addition of a dopant. The resolution of the resist is better than 0.3 μm.

120 citations


Patent
11 Jul 1983
TL;DR: In this article, a plastic substrate is injection molded to provide a pattern of channels in at least one of its sides to define a predetermined set of conductive paths, and the surfaces of the channels and the non-channel surfaces therebetween are metalling through one or more steps of flame spraying, a combination of electroless plating and electroplating, gas plating or vacuum deposition.
Abstract: A plastic substrate is injection molded to provide a pattern of channels in at least one of its sides to define a predetermined set of conductive paths. Both the surfaces of the channels and the non-channel surfaces therebetween are metalling through one or more steps of flame spraying, a combination of electroless plating and electroplating, gas plating or vacuum deposition. In one form of the invention the metallization over the non-channel surfaces is removed by abrading. In another form of the invention the initial metallization over the non-channel surfaces is coated with a resist prior to the deposition of another metal layer. The metal covering the channels is subsequently removed by stripping the resist and etching away the initial metallization.

107 citations


Journal ArticleDOI
TL;DR: In this paper, the main results obtained in microlithography with Langmuir-Blodgett (LB) films as photoresists are surveyed, and criteria for the choice of a molecule are specified, in respect of film quality, sensitivity, contrast and cross-linking.

79 citations


Patent
03 Aug 1983
TL;DR: In this paper, an optical system for determining and reproducing spatial separation of features in the range of 80 to 2500Å for optical microscopy and lithography using visible light, the system being independent of the wavelength of the incident light.
Abstract: An optical system for determining and reproducing spatial separation of features in the range of 80Å to 2500Å for optical microscopy and lithography using visible light, the system being independent of the wavelength of the incident light. An aperture mask is provided having at least one aperture of between about 80Å and 2500Å diameter. The mask may be used in optical microscopy to view objects with a high degree of resolution by placing the mask within the near field of light emanating from a sample to be viewed. The mask may also be used for high resolution optical lithography by placing a resist material within the near field of light passing through the mask.

76 citations


Journal ArticleDOI
TL;DR: In this article, Nitrocellulose films have been shown to function as self-developing resist layers that are sensitive to both low energy ( 25:1) and high energy (2.5 µm) ion beam.
Abstract: Nitrocellulose films have been shown to function as self‐developing resist layers that are sensitive to both low‐energy ( 25:1 have been demonstrated using a stencil mask and an argon ion beam; the resolution obtained was mask limited. The sensitivity of the resist to 2‐keV Ar+ ions is 36 μm/min at beam currents of 1 mA/cm2, allowing exposure times of 1 s for 0.5 μm of resist. The material is capable of functioning as a mask material for typical semiconductor dry etching processes.

73 citations


Patent
11 Nov 1983
TL;DR: In this article, an opaque gate electrode is formed on a transparent substrate, and the substrate is coated with a negative resist, which is then exposed and developed; thereafter, a gate insulation film is deposited on the substrate by etching an insulation film.
Abstract: PURPOSE:To enable to inhibit the generation of the defect of short circuiting between a semiconductor film and a gate electrode by a method wherein an opaque gate electrode is formed on a transparent substrate, and the substrate is coated with a negative resist, which is then exposed and developed; thereafter, a gate insulation film is deposited on the substrate by etching an insulation film. CONSTITUTION:The opaque gate electrode 9 of chromium, aluminum silicon, molybdenum, or the like is formed on a transparent plate 8 of quartz or sapphire. Next, after the insulation film 10 of SiOx or SiNx is deposited, it is coated with the negative resist 11 with a coater and the like and irradiated (exposed) with light 12 from back of the transparent substrate 8. Then, the insulation film is etched with the negative resist as a mask, resulting in resist exfoliation; thereafter, the gate insulation film 14 of SiOx or SiNx is deposited. The semiconductor film 15 of amorphous Si or poly Si and the source electrode 16 and the drain electrode 17 of aluminum silicon of aluminum are formed.

69 citations


Journal ArticleDOI
TL;DR: In this paper, the limitations on ω-tricosenoic acid deposition speed are investigated and a model is proposed to explain the observations, based on molecular reorganization and is thought to have general applicability to LB film deposition.

69 citations



Patent
12 Dec 1983
TL;DR: In this article, the resist pattern was prevented from becoming thinner than a desired width by the light reflection at the step of an Al layer by coating a resist of refraction coefficient n1 and a resist on the Al layer when etching it.
Abstract: PURPOSE:To prevent the resist pattern from becoming thinner than a desired width by the light reflection at the step of an Al layer by coating a resist of refraction coefficient n1 and a resist of refraction coefficient n2 on the Al layer when etching it CONSTITUTION:After evaporation of an Al layer 13, a first resist 141 with refraction coefficient n1 is coated on it, and then a second resist 142 with refraction coefficient n2 is coated on the first resist 141 Both coefficients have the relationship of n1>n2 Since a light that passes through a mask 15 is totally reflected at between the resist 141 and resist 142, the light after the reflection is as shown by Fig B, and the tightness of the contact of the resists with the Al face is increased, eliminating gaps among them Thereby the cut in the Al layer and Al wirings due to steps can be prevented

Journal ArticleDOI
TL;DR: In this article, the use of monomer-polymer multilayers has been used for fine line resolution of resist patterns in a computer-controlled electron beam technique, achieving an order of magnitude higher resolution than conventional resist resolution.

Patent
09 Nov 1983
TL;DR: In this article, a method of fabricating MESFET devices having a submicron line gate electrode is disclosed, which includes the formation of a single layer of resist material on a semiconductor surface, formation of the resist cavity through optical lithography, the cavity exposing a selected portion of the semiconductor surfaces, depositing by way of angled evaporation at least one gate wall within said resist cavity, the gate wall defining a shaped gate cavity; depositing gate electrode material within the gate cavity, and removing the resist material.
Abstract: A method of fabricating MESFET devices having a submicron line gate electrode is disclosed. The method includes the formation of a single layer of resist material on a semiconductor surface; formation of a resist cavity through optical lithography, the cavity exposing a selected portion of the semiconductor surface; depositing by way of angled evaporation at least one gate wall within said resist cavity, the gate wall defining a shaped gate cavity; depositing gate electrode material within the gate cavity, and removing the resist material. In one embodiment of the invention the gate wall is removed from the gate electrode material, leaving a free-standing electrode. In another embodiment, the gate wall is a permanent part of the electrode structure.

Journal ArticleDOI
TL;DR: In this paper, a single target shot of a frequency-tripled Nd:glass laser (λ=0.35 μm, 35 J in 1 ns) was found to be sufficient for submicron x-ray lithography in poly(butene‐1‐sulfone) (PBS) or poly(glycidyl‐methacrylate‐ethyl acrylate) (COP) resists.
Abstract: X‐ray lithography was studied, using laser‐produced plasma as a source. A single target shot of a frequency‐tripled Nd:glass laser (λ=0.35 μm, 35 J in 1 ns) was found to be sufficient for submicron x‐ray lithography in poly(butene‐1‐sulfone) (PBS) or poly(glycidyl‐methacrylate‐ethyl acrylate) (COP) resists. The incident x‐ray flux is about an order of a magnitude smaller than that normally required. This behavior could be the result of the transient character of the exposure and an abrupt rise in the resist temperature.

Patent
15 Aug 1983
TL;DR: In this article, a method of fabricating gallium arsenide devices in which contact isolation is provided by a deep mesa step structure was proposed, and the fabrication of monolithic planar mixer millimeter-wave diodes with low series resistance and reduced parasitic capacitance.
Abstract: A method of fabricating gallium arsenide devices in which contact isolation is provided by a deep mesa step structure. Step coverage of deposited conductive films is facilitated by preferential orientation of the non-centrosymmetric crystal substrate and wet anisotropic etching that provides a sloped step. Problems of fine line definition of the Schottky anode contact in the photolithographic process are addressed by a two-step exposure of a single layer of thick photoresist followed by a chlorobenzene soak prior to development that ensures a retrograde resist profile needed for good lift-off of undesired evaporated metal. Mesas as deep as 7 μm have been obtained, which permit the fabrication of monolithic planar mixer millimeter-wave diodes with low series resistance and reduced parasitic capacitance.

Patent
21 Nov 1983
TL;DR: In this article, a positive photoresist system was proposed to achieve high resolution images by exposure to a wide range of wavelengths and development using an aqueous base developer, which is also suitable for use as a planarizing layer in a multiple layer system.
Abstract: This invention relates to a positive photoresist system possessing a high degree of thermal stability. The photoresist system contains a preformed polyglutarimide polymer dissolved in a non-reacting solvent. The positive resist is capable of achieving high resolution images by exposure to a wide range of wavelengths and development using an aqueous base developer. The photoresist system is also suitable for use as a planarizing layer in a multiple layer system.

Journal ArticleDOI
TL;DR: In contrast enhancement as discussed by the authors, a very thin bleachable layer is applied to the photoresist surface, followed by conventional exposure, the layer is removed and the resist developed in the ordinary way.
Abstract: This paper will describe a new concept for the production of high contrast photopatterns. The method is designed to produce good quality patterns with very low contrast illumination through the use of photobleachable materials in conjunction with standard photoresists. A very thin bleachable layer is first applied to the photoresist surface. Following conventional exposure, the layer is removed and the resist developed in the ordinary way. As a result of the presence of the bleachable material, the contrast of the illumination that reaches the photoresist is increased. It is for this reason that the technique is called contrast enhancement. The degree to which the contrast is enhanced depends on both the photochemical properties of the bleachable material and the dose required to expose the underlying resist. The paper will discuss properties required of the bleachable material in order to make the technique feasible, such as the magnitudes of the extinction coefficient and the quantum yield. Bleaching experiments on candidate materials for the characterization of these parameters will be described. Also to be discussed is a model of the bleaching dynamics, which was used to calculate the improvements in contrast that are achieved as a function of base resist sensitivity. The extra processing steps required by the presence of the bleachable layer will be covered. Submicron resist patterns that demonstrate the resulting improvement in contrast will also be shown.

Patent
29 Apr 1983
TL;DR: In this article, the active channel area is defined by a photoresist pattern, and Ions are implanted into the exposed area in a concentration to achieve a desired threshold in order to control the threshold potential.
Abstract: A method of fabricating field effect transistors which includes control of threshold potential by an ion implantation limited to the active channel area. The active channel area is defined by a photoresist pattern. Ions are implanted into the exposed area in a concentration to achieve a desired threshold. Appropriate metals are deposited over the channel area to form a gate electrode. The photoresist is lifted off leaving the gate electrode in position over the channel area. If desired, a layer of polysilicon can be included prior to resist formation and later removed by an etchant which does not attack the gate electrode.

Patent
28 Feb 1983
TL;DR: In this article, the authors proposed a method to make an opening hole with high accuracy by a method, in which a resist film on one side of raw material for a mask is made thicker than the film on the other side, corresponding to the etching speed and quantity on the large diameter side and the small diameter side respectively, while performing etching process by making the impact force on the first half film stronger than the second half impact force.
Abstract: PURPOSE: To make an opening hole with high accuracy by a method, in which a resist film on one side of raw material for a mask is made thicker than the film on the other side, corresponding to the etching speed and quantity on the large diameter side and the small diameter side respectively, while performing etching process by making the impact force of an etching liquid on the first half film stronger than the second half impact force. CONSTITUTION: A resist film 4 on the roller 8 side is formed thicker than the resist film 4 on the roller 7 side by applying rollers 7 and 8 from both sides while drawing up the raw material 1 for a shadow mask through a photosensitive liquid 4, under such conditions that, for instance, the rollers 7 and 8 are firstly placed symmetrically as shown in dotted line, thereafter, the center of the roller 7 on one side is set up higher by h 1 than the liquid surface, while the center of the other roller 8 is set up lower by h 2 . Thereby, the thickness of the resist films 7 on the larger hole side and on the smaller hole side are preferably, for instance, 5W12μm and 3W6μm respectively. Next, the etching is performed under the condition that the impact force on the resist film may be, for instance, 5W10kg/cm 2 in the first half of etching, while the impact force on the resist film may be 2.5W5kg/cm 2 in the second half of etching. Thereby, an opening hole can be effectively made with high accuracy with no damage to the resist film. COPYRIGHT: (C)1984,JPO&Japio

Journal ArticleDOI
David C. Joy1
TL;DR: In this article, a Monte Carlo simulation was used to model two special situations: a thin, freestanding, resist and a thin resist on a bulk substrate to calculate the exposure conditions required for the highest resolution lithography in this condition.

Journal ArticleDOI
TL;DR: In this paper, the authors investigate the possibility to extend optical lithography well into the submicron regime, given a multilayer resist system that confines imaging to a thin layer, and that eliminates reflection from the substrate.
Abstract: It may be possible to extend optical lithography well into the submicron regime, given a multilayer resist system that confines imaging to a thin layer, and that eliminates reflection from the substrate. The necessary exposure and focus tolerances are determined by simulating the projection of partially coherent, diffraction‐limited images onto an ideal multilayer resist system. Exposure–defocus diagrams are then generated by requiring that critical dimensions satisfy a ±10% tolerance. We investigate the prospects for submicron lithography with 0.75 and 0.5 μm minimum features. Two lens systems are analyzed; a commercially available 0.28 NA lens operating at 436 nm, and an advanced 0.35 NA lens operating at 365 nm. The features studied include contact holes, rectangular lines and spaces, and equal line space gratings, and are representative of many typical IC mask patterns. Linewidth tailoring or biasing allows these features to be printed within tolerance simultaneously if the exposure can be controlled ...

Journal ArticleDOI
TL;DR: In this article, the general characteristics and applications of ion bombardment of resists are described and the applications of conventional ion beam lithography to range measurements in polymers and microstructure fabrication are presented.

Patent
22 Aug 1983
TL;DR: In this paper, a positive-working process is used to produce relief images or resist images using a solid photosensitive resist layer which is applied to a base and contains a compound possessing two or more aromatic and/or hetero-aromatic o-nitrocarbinol ester groups and crosslinking compounds possessing two reactive groups which are capable of reacting with carboxyl groups to form a covalent chemical bond.
Abstract: Relief images or resist images are produced by a positive-working process, using a solid photosensitive resist layer which is applied to a base and contains a compound possessing two or more aromatic and/or heteroaromatic o-nitrocarbinol ester groups and crosslinking compounds possessing two or more reactive groups which are capable, under the action of heat, of reacting with carboxyl groups to form a covalent chemical bond. To produce the relief images or resist images, the photosensitive resist layer is first exposed imagewise to actinic light, the exposed areas of this layer are then washed out with an aqueous developer, the remaining resist layer is post-exposed uniformly to actinic light and finally the post-exposed resist layer is thermally crosslinked and hardened.

Journal ArticleDOI
TL;DR: The resist materials used today in the fabrication of semiconductor devices were originally developed for use in the printing industry and were simply adopted by the electronics industry with relatively minor modifications as discussed by the authors.

Patent
10 Nov 1983
TL;DR: In this article, a printed wiring board of the type that places a solder mask over bare copper circuit traces is laid down with a flat planar surface by means of a liquid photopolymer solder mask layer deposited, photoexposed and developed to uncover those circuit trace positions such as through holes and connector pads for further processing.
Abstract: In a printed wiring board of the type that places a solder mask over bare copper circuit traces, the solder mask is laid down with a flat planar surface by means of a liquid photopolymer solder mask layer deposited, photoexposed and developed to uncover those circuit trace positions such as through holes and connector pads for further processing. Then a very thin copper layer is chemically deposited over the surface area and a resist layer is laid down as a cover insulating layer on the flat surface so that a thicker layer of copper may be electrolytically plated over the uncovered circuit traces. In this manner the conductive area about each of the connector pads is significantly increased by plating on the sidewalls of the solder mask layer which surround the connector pads. Additionally the photopolymer flat surface is glossy and does not strongly adhere to the deposited thin copper layer as does the sidewall and conductor pad areas, thereby permitting the cover insulating layer and the thin copper layer to be readily removed from the flat planar surface by mechanical methods.

Journal ArticleDOI
TL;DR: In contrast enhancement as mentioned in this paper, a photobleachable layer is applied to the resist surface to improve the imaging properties of conventional photoresist through the use of a photopattern.
Abstract: This paper introduces a new method, contrast enhancement, which improves the imaging properties of conventional photoresist through the use of a photobleachable layer applied to the resist surface. Contrast enhancement allows high contrast photopatterns to be formed even when low contrast illumination is used. A short discussion of the theory and an experimental demonstration of the method are presented.

Journal ArticleDOI
TL;DR: Proprietes de corrosion de polymeres organosilicies, caracteristiques d'exposition a un faisceau d'electrons et aux UV lointains des homo-and copolymeres de trimethylsilylstyrene.
Abstract: Proprietes de corrosion de polymeres organosilicies, caracteristiques d'exposition a un faisceau d'electrons et aux UV lointains des homo- et copolymeres de trimethylsilylstyrene. Application du copolymere d'un systeme resist bicouches

Journal ArticleDOI
TL;DR: In this paper, high resolution (approximately 10 nm) patterns were written at all beam energies with an exposure latitude that remained approximately constant up to energies for which the range of the backscattered electrons became significantly larger than the pattern area.
Abstract: We have performed electron beam lithography studies on thick substrates using beam energies of 20–120 keV and a nominal beam diameter of 2 nm in a Philips 400 electron microscope with scanning capability. Metal lines as narrow as 10 nm were fabricated on Si and GaAs substrates using liftoff of a single thin layer of resist. High resolution (approximately 10 nm) patterns could be written at all beam energies with an exposure latitude that remained approximately constant up to energies for which the range of the backscattered electrons became significantly larger than the pattern area. For large area patterns written with the small beam, the proximity effect is greatly reduced, even at 20 keV, because of the sharp edge of the exposure profile. At high beam energies, the range of backscattered electrons is large enough that they contribute only a slowly varying background dose, leading to a relatively simple proximity correction even for complex patterns.

Journal ArticleDOI
TL;DR: In this article, a profilometer is used to measure the step height changes of isolated line features of various dimensions and the viscosity of the solution appears to give a reasonable indication of the spun-on planarization properties.
Abstract: The planarization properties or thickness changes on topographical features are examined in detail for several types of spun‐on polymer films. A profilometer is used to measure the step height changes of isolated line features of various dimensions. The viscosity of the solution appears to give a reasonable indication of the spun‐on planarization properties. However, in many cases, the thermal flow of the polymer during a subsequent curing procedure is the dominant planarization mechanism. Methods for producing highly planarized surfaces with positive resist materials are described along with the effects of feature size on the planarization properties.

Patent
17 Nov 1983
TL;DR: In this paper, the authors proposed a method to form a highly reliable wiring for the titled semiconductor device by a method wherein, after the second insulating film has been formed on the back side of a substrate immediately before or immediately after the processing, an unnecessary metal layer is removed, and a desired metal wiring is formed.
Abstract: PURPOSE:To form a highly reliable wiring for the titled semiconductor device by a method wherein, after the second insulating film has been formed on the back side of a substrate immediately before or immediately after the processing wherein a metal layer will be coated on the first insulating film provided on the surface of the substrate, an unnecessary metal layer is removed, and a desired metal wiring is formed. CONSTITUTION:A metal 9 such as aluminum and the like is coated on the insulating film 8 such as an SiO2 and the like which will be provided on the semiconductor substrate 1 by performing a vapor-deposition method, for example, while at this time, the second insulating film 12 is present on the back side of the semiconductor substrate 1. Then, a resist film 10 is formed using the photoresist such as OMR (negative type) or AZ (positive type) or the like, for example. Subsequently, the unnecessary part of the metal is going to be removed by performing dry etching method, but as the second insulating film 12 exists on the back side of the semiconductor substrate 1, no current coming from the battery flows on the wiring connected to a P insulating region 3, and a desired metal wiring pattern can be formed without accompanying abnormal over-etching or corrosion being in progress. Subsequently, the resist film 10 is removed, and the formation of the metal wiring is completed.