Showing papers on "Resist published in 1984"

A mathematical model for spin coating of polymer resists

Abstract: The success of lithographic processes in microelectronics fabrication depends on the reproducible generation of desired polymer resist film thickness and profile uniformity. Numerous process variables affect the outcome of spin coating of resists on wafers. A thorough understanding of the intricate interdependence of process parameters is essential to guide future process design and improvement. A mathematical model is derived to elucidate the dominant mechanisms governing film formation. The non‐Newtonian character of the resist solution is taken into account, as well as the changes in resist viscosity and solvent diffusivity with changing polymer concentration. Results obtained from this model show that polymer film thickness is controlled by convective radial flow of the resist solution and solvent evaporation. The former process governs film thickness during the early stages of the process, while the latter becomes significant in later stages. The model accurately describes the experimentally observed dependence of film thickness on the variables affecting the spin‐coating process.

The phase-shifting mask II: Imaging simulations and submicrometer resist exposures

Abstract: Submicrometer optical lithography is possible with conventional projection cameras when the mask controls the phase of the light at the object plane. Two-dimensional imaging simulations for the Mann 4800 projection camera show that the maximum spatial frequency for 60-percent contrast increases from 640 1/mm to 896 1/mm. The geometrical quality of the images of typical microcircuit patterns was shown to be acceptable for feature sizes of 0.7, 0.6, and 0.5 µ, respectively, and various parameters of the irradiance patterns were calculated. Exposures were made using a high-performance two-layer photoresist system and a mask containing patterns similar to those in the simulation. The phase-shifting mask was shown to increase exposure latitude and to produce a 95-percent yield of 833 1/mm (0.6 µ line and gap) patterns, whereas the transmission mask gave a 7-percent yield. Half micrometer features were patterned with a 22-percent yield using 0.436-µ light.

Use of plasma polymerized organosilicon films in fabrication of lift-off masks

Abstract: Pinhole-free thin films deposited by glow discharge or plasma polymerization of organosilanes, organosilazones and organosiloxanes for use as reactive ion etch oxygen barriers in multilayer resist structures, of lift-off masks, for fabrication of semiconductor devices, such as integrated circuits. The process includes deposition of thin plasma polymerized organosilicon barrier film over a radiation insensitive polymeric base layer previously coated on a substrate, followed by thermal annealing of the plasma polymerized barrier layer, over which is then coated a radiation sensitive resist layer. After definition of the desired resist pattern by imagewise exposure and development, the image is etch transferred into the barrier layer by reactive sputter etching in a fluorine containing ambient, and subsequently transferred into the base layer, down to the substrate, in an oxygen plasma, during which time the plasma deposited film functions as an oxygen barrier. Final metal patterns are formed by metallization and lift-off steps.

Composite back-etch/lift-off stencil for proximity effect minimization

Abstract: This composite back-etch/lift-off stencil method avoids the uncontrolled changes in the properties of contacts in small devices caused by the close proximity of the lift-off resist stencil to the contact area during the precleaning, surface preparation and metal deposition processes. This method limits the area of the wafer exposed to back-etching and thus restores the freedom of choice of contact metallurgy. Back-etching is only applied in the areas of the wafer near to the contact holes; lift-off techniques are used for the rest of the integrated circuit.

Process for producing micro Fresnel lens

Abstract: A process for producing a micro Fresnel lens comprises the following steps: moving either a substrate coated with a resist layer for providing the micro Fresnel lens or a source of actinic radiation such as electron beam for exposing the resist layer relative to each other in a fixed direction; scanning linearly the resist coat with the actinic radiation in a direction perpendicular to the direction of the relative movement; during the scanning operation, performing exposure to the actinic radiation or interrupting or overlapping the application of the actinic radiation so as to form a latent image in an area corresponding to the grooved surface of the micro Fresnel lens within a predetermined width; repeating the above procedures in a direction perpendicular to that of the relative movement of the substrate and the source of actinic radiation; and developing the exposed resist layer to provide a micro Fresnel lens having the desired grooved surface.

Manufacture of semiconductor device

Abstract: PURPOSE:To obtain a multilayer wiring forming method, through which a first layer wiring made of an Al/Cu alloy is not corroded even through treatment by an acid when removing resist slag, by previously leaving an anodic oxidation film when a through-hole is formed to an insulating film and removing the anodic oxidation film through reverse sputtering when forming a second layer wiring. CONSTITUTION:The Al/Cu alloy 12 is formed on an SiO2 film 11 on a semiconductor substrate in the thickness of 0.6mum through whole-surface sputtering, and the anodic oxidation film 13 is formed in the film thickness of 100Angstrom -200Angstrom . A resist is applied on the whole surface to form a resist film, and the anodic oxidation film 13 and the Al/Cu alloy layer 12 are etched through dry etching while using resists 14 obtained by patterning the resist film as masks to form the first layer Al/Cu alloy wirings 12a. When the resist films 14 are exfoliated through dry etching, the resist slag 14a remains on the anodic oxidation films 13. The resist slag 14a is removed by an oxalic acid liquid in the same manner as a conventional method. In the treatment by the acid, the first layer wirings 12a made of the Al/Cu alloy are not corroded by oxalic acid because their surfaces are coated with the anodic oxidation films 13, and remain in a complete shape.

AlF3—A new very high resolution electron beam resist

Abstract: Using dose resolved energy loss and energy filtered imaging, the mechanism of a new high resolution resist, AlF3, is examined It is found that exposure induces mass loss including the displacement of Al ions From the energy filtered images, it is observed that the Al coats the walls of the exposed area Further, it is demonstrated that high resolution patterns exposed in AlF3 can be replicated into Si3N4 substrates

X-ray lithography system

Abstract: An x-ray lithography system is disclosed in which x-rays are generated by directing a high energy laser beam against a metal target to form an x-ray emitting plasma. The x-rays from the plasma are then directed through a mask towards a resist covered wafer to cause a patterned exposure on the wafer resist coating. The mask, the portion of the target which the laser beam strikes and the portion of the wafer to be exposed are all within an evacuated chamber. The laser, prior to entering the chamber, is split into two separate beams, each of which are focused and directed through a window in the side of the chamber towards the same spot on the target. Apparatus, including an air bearing, seal and positioner, is provided to move the target at periodic intervals. Similar apparatus is provided to move the wafer from exposure section to exposure section. The laser beam system includes a face pumped laser beam amplifier and unidirectional beam expanders to allow the maximum energy to be transferred to the laser beam by the amplifier. A series of two or more laser pulses are provided in order to maximize the energy obtained from the laser amplifier. A magnet and a membrane shield are also provided to prevent high energy particles and dust contaminants from the plasma from effecting the lithography process. A materials handling device is provided for moving wafers, targets and masks and an alignment system operating within the evacuated chamber, positions of the wafer with respect to the mask prior to the exposure thereof.

Method for manufacturing an optical memory element

Abstract: An optical memory element includes stripe-shaped grooves formed directly on a glass substrate. To manufacture the optical memory element, a resist film is disposed on the glass substrate, and the groove pattern is formed in the resist film. A reactive ion etching is conducted through the groove pattern formed in the resistfilm so as to form the guide grooves in the glass substrate. After removing the resist film from the glass substrate, a magneto-optical recording layer is formed on the glass substrate.

Method for manufacture of printed wiring board

Abstract: A method for the manufacture of a printing wiring board, which proves particularly useful as a printed coil, is characterized by the fact that in the work in process which has undergone the step for fomation of a conductor circuit and which has not undergone the step for separation of a plating resist, the plating resist and other insulating substratal material are separated for transfer from the surface of the substrate having the conductor circuit formed thereon. Since this method permits formation of an extremely thin insulating layer and a conductor circuit layer thicker than the insulating layer, it enables production of very thin printed wiring board and printed coil (8) having high circuit density in the surfaces of component layers as well as in the direction of superposition of component layers.

Resist process using anti-reflective coating

Abstract: The present invention teaches a two-and-one-half-level resist process, wherein a first planarizing resist layer is applied, an anti-reflective coating (which need not be a photoresist itself) is applied, and then a top photoresist layer is applied. The top layer is patterned conventionally, at a wavelength which the anti-reflective coating absorbs, and a flood exposure (preferably in deep ultraviolet light) is then used to transfer this pattern to the bottom planarizing resist layer. Good patterning of non-planar surfaces despite topography is thus achieved, and pattern degradation due to spurious reflections (e.g., from an aluminum layer being patterned) is avoided.

Semiconductor integrated circuit device

Abstract: PURPOSE:To obtain the semiconductor integrated circuit device with a color filter of high reliability, which resists heat and color characteristics thereof of not change by heat, by forming the quality of material for the color filter by an inorganic compound. CONSTITUTION:A semiconductor substrate 101 on which an image pickup element is formed is coated with aluminum in approximately 1mum, and aluminum is changed into porosity partially. The semiconductor substrate 101 selectively coated with a resist such as a photo-resist is used as an anode and a platinum plate as a cathode-that is, anodic oxidiation, is executed selectively. Consequently, porous aluminum oxide layers 103 and aluminum layers 102 can be formed. The aluminum layers 102 are formed in regions coated with photo-resist, and the aluminum oxide layers 103 are formed in regions to which anodic treatment is executed. The porous aluminum oxide layers 103 are dyed, thus forming the color filters. Photoelectric elements are formed under the regions 103 used as the filters, and the lower sections of the aluminum layers 102 correspond to element isolation regions.

Submicron, vacuum ultraviolet contact lithography with an F2 excimer laser

Abstract: An F2 excimer laser at 157 nm has been used for the first time as an exposure source for high resolution photolithography. At this short wavelength, conventional glass and quartz mask substrates are opaque, and therefore alkaline‐earth halides and sapphire were used as mask substrates. The masks were patterned by electron beam lithography, and mask features as narrow as 150 nm have been replicated and represent the smallest features yet produced by contact photolithography.

Use of depolymerizable polymers in the fabrication of lift-off structure for multilevel metal processes

Abstract: An improved lift-off process for multilevel metal structure in the fabrication of integrated circuits by employing lift-off layer formed from polymers which undergo clean depolymerization under the influence of heat or radiation and allow rapid and residue-free release of an "expendable mask". An embedded interconnection metallurgy system is formed by application of the lift-off layer of this invention over a cured polymer film or on an oxygen RIE barrier layer previously deposited on organic or inorganic substrate, followed by another barrier over which is then coated a radiation sensitive resist layer. After definition of the desired resist pattern by imagewise exposure and development, the image is replicated into the barrier by sputter etching in a fluorine containing ambient and subsequently into the base layer down to the substrate by oxygen reactive ion etching which is followed by blanket metal evaporation and finally the lift-off by brief heat treatment at the depolymerization temperature of the lift-off layer, and brief solvent soak.

Manufacture of semiconductor device

Abstract: PURPOSE:To prevent the breakdown of a wiring at a contact region, by forming metal on a contact region, thereafter forming an interlayer insulating film, applying positive type resist thereon, exposing and developing the entire surface, forming a hole in the positive resist on the contact region, and thereafter performing etching. CONSTITUTION:A positive type resist film 17 is applied on a part, where an interlayer insulating film 16 is formed. The thickness of the positive type resist film becomes thin at a part, where a step part is steep, or at a region, where the step part is high. When the entire surface of a wafer is exposed under this state, the thin positive type resist film on the region, where metal is formed, is exposed to light, which is reflected from the surface of the metal, and the light from the upper side. Therefore, the amount of the absorbed light becomes much in comparison with the resist film in the other region. When development is performed, the positive type resist film on the region, where the metal is formed, is developed in a developing time shorter than the time for the positive type resist in the other region. Then, the interlayer insulating film on the metal is etched, and the surface of the metal is exposed. The positive type resist film is removed, and a lower metallic wiring layer 18, which is to become a wiring, is formed. Thus a contact region and the metallic layer 18, which is to become the wiring, are connected.

Manufacture of semiconductor device

Abstract: PURPOSE:To make is possible to obtain an alignment mark which is high in both positioning accuracy and S/N, by simultaneously forming an element-forming pattern and an alignment mark-forming pattern on an insulating film, and forming an alignment mark by the use of the latter pattern. CONSTITUTION:An emitter-forming oxide film 11 is deposited on a substrate 1. The film 11 is coated with a resist film 12, on which an emitter hole pattern 13A and a mark pattern 14A are simultaneously formed. The film 11 is etched to form emitter holes 13B and a mark pattern 14B, and the resist film 12 is removed. The oxide film 11 is coated with a shielding film 15. The portion of the film 15 in a mark area part 16 is removed. With the oxide film in the mark area part employed as a mask, etching is carried out to form a stepped mark 17. The film 15 is removed, thereby to complete an alignment mark. By this manufacturing method, the positioning accuracy between the mark-forming pattern and the element-forming pattern is extremely high. In addition, it is possible to obtain an alignment mark with a large S/N in the electron-beam or optical aligner system.

Method and apparatus for forming resist pattern

Abstract: A method for forming a highly precise resist pattern with good reproducibility has the steps of: applying a resist material to a substrate to form a resist film; baking the resist film; cooling the resist film in a controlled manner; selectively irradiating the resist film with one of electromagnetic waves in a predetermined wavelength range and particle beam having predetermined energy; and developing the resist film to form a resist pattern.

Gas‐Phase‐Functionalized Plasma‐Developed Resists:Initial Concepts and Results for Electron‐Beam Exposure

Abstract: Fonctionnalisation par reaction en phase gazeuse avec des reactifs mineraux ou organometalliques par liaison selective des atomes mineraux aux regions des resists exposes ou non

Manufacture of semiconductor device

Abstract: PURPOSE:To enable the employment of an economical contact type exposing apparatus by utilizing a negative photo resist other than that of the cyclized rubber system for the photolithography process in manufacture of a semiconductor device in the minimum manufacturing size of 5mum or less CONSTITUTION:In the figure, 7 is negative photo resist allowing the resist film of sensitive part to remain and 8 is the sensitive part An ordinary negative photo resist has the sufficient strength of film, no adhesiveness to photo mask 5 and bad resolution Therefore, the negative photo resist other than that of cyclized rubber system is used for the photolithography Since the negative photo resist has the strength of film and the exposure is carried out using a contact type exposing apparatus for the exposing process As explained above, an economical contact type exposing apparatus can be used and manufacturing cost of semiconductor device can be reduced

Electron lithography apparatus

Abstract: An electron image projector for transferring mask patterns onto a semiconductor wafer comprises a patterned photoemissive cathode mask and a target formed by the semiconductor wafer coated with an electron sensitive resist. A patterned electron beam is projected from the cathode onto the target with unity magnification by acceleration with a uniform electric field E and focussing by a uniform magnetic field H. The electric field E is established between the cathode and an electron permeable anode grid situated between the cathode and the target. For fast alignment with low power consumption, beam deflection is achieved electrostatically. The electrostatic deflection plates which may be integral with the anode grid or form part of a further grid, are arranged for deflecting at least part of the beam as it travels from the anode grid to the target. In one arrangement to correct for misalignment, the entire beam is deflected in the same direction. In another arrangement part of the beam is oscillated in one direction, while another part of the beam is simultaneously oscillated at a different frequency in a different direction, and phase sensitive detection is used to align the mask and the target.

Image-recording materials and image-recording carried out using these

Abstract: A resist film comprises a dimensionally stable base (B), which is transparent to actinic light in the wavelength range from 300 to 420 nm, and a mask-forming layer (ML) which is sensitive to heat radiation and contains a thermochromic system which, when irradiated with an IR laser having a wavelength greater than 1.00 μm, undergoes an irreversible change in its absorption spectrum in the wavelength range from 300 to 420 nm so that the optical density of the mask-forming layer (ML) in this wavelength range changes by not less than 1.3 units. The base of the resist film can also be applied onto the photosensitive relief-forming layer (RL) of a recording material to give a multilayer image-recording material. Imagewise irradiation with heat, for example using an IR laser, produces, in the mask-forming layer (ML) of the resist film, a UV photomask which is very useful for exposing photosensitive recording materials.

Development of a New Nickel-Base Superalloy

Abstract: A wrought nickel-base superalloy based on the Ni-Cr-W system was developed for high-temperature applications. The new alloy is solid solution and carbide strengthened. It is essentially free of cobalt, and it resists the formation of detrimental intermetallic compounds after prolonged exposure to elevated temperatures. Various mechanical, oxidation and physical properties of the new alloy were measured, and the microstructural features were characterized. These were compared with those of other solid solution-strengthened superalloys. Also, the fabricability of the alloy was evaluated. A number of advantages of the new alloy are defined.

Method of forming resist pattern

Abstract: A method of forming a resist pattern, which comprises printing a predetermined pattern on a substrate by a lithographic technique using a resist ink curable by irradiation of an active energy ray and/or heating, said ink containing (1) a metal chelate resin obtained by reacting (a) at least one resin selected from the group consisting of alkyd resins, modified alkyd resins, fatty acid-modified epoxy resins, urethanized oils and maleinized oils and (b) a metal compound capable of forming a coordination bond using the resin (a) as a ligand and (2) a polymerizable compound containing at least two ethylenically unsaturated bonds per molecule; and curing the printed pattern by irradiating an active energy ray and/or by heating.

Planarization of multi-level interconnected metallization system

Abstract: The planarization of structures having vertical interconnection studs embedded in an insulator layer utilizing a resist layer with dry etching in a CF 4 ambient for equal etching of resist and the insulation to planarize the insulation, followed by dry etching in essentially a noble gas (argon) ambient for equal etching of the insulator layer and stud metal to desired planarization.

Electron beam enhanced surface modification for making highly resolved structures

Abstract: A method for forming high resolution submicron structures on a substrate is provided by direct writing with a submicron electron beam in a partial pressure of a selected gas phase characterized by the ability to dissociate under the beam into a stable gaseous leaving group and a reactant fragment that combines with the substrate material under beam energy to form at least a surface compound. Variations of the method provide semiconductor device regions on doped silicon substrates, interconnect lines between active sites, three dimensional electronic chip structures, electron beam and optical read mass storage devices that may include color differentiated data areas, and resist areas for use with selective etching techniques.

Process for delineating photoresist lines at pattern edges only using image reversal composition with diazoquinone

Abstract: An optical photolithographic process in which resist lines having widths in the micron and sub-micron range are produced without the use of a fine line photomask. A positive photoresist having an additive for image reversal is applied to the surface of a semiconductor substrate. The photoresist is exposed through a photomask to ultraviolet light. The edges of the opaque sections of the mask diffract the ultraviolet light, forming partially exposed areas between the exposed and unexposed areas formed in the photoresist. After development in a solvent to remove the exposed areas, the photoresist undergoes an image reversal process. The photoresist is first baked at 100° C. for 30 minutes. During this bake step, the photoactive decomposition products present in the partially exposed areas react, freezing the solubility of the partially exposed areas with respect to that of the unexposed areas. The photoresist is then blanket exposed and developed in a solvent, leaving the partially exposed areas on the substrate. The resulting thin resist lines can be used to form narrow isolation trenches by coating the substrate with a quartz film and lifting off the resist lines.

Polysilane Bilayer uv Lithography

Abstract: Polysilanes are a class of Si-Si backbone polymers that have been demonstrated to function as high resolution positive resists with excellent uv sensitivity. These materials have a unique photochemistry with high quantum yields and nonlinear bleaching. Polysilanes serve as excellent RIE barriers for bilevel resist applications because a protective layer of SiO 2 is formed during exposure to an oxygen plasma. Aliphatic polysilanes have been applied to full wafer mid-uv lithography with 0.75 μm resolution.

Manufacture of semiconductor device

Abstract: PURPOSE:To obtain an MOS semiconductor device of high reliability enabled to be formed in high deisnity, in high integration and to act in a high speed by a method wherein high concentration impurities are introduced using a gate and a film on the side wall of the gate as masks to form high concentration diffusion layers. CONSTITUTION:After a gate oxide film 2 and a gate electrode 3 are formed on a P-type substrate 1, phosphorus ions are implanted to form low concentration diffusion layers 4. Then after a nitride film 5 is adhered, a resist 6 is applied, and the resist on a source region and on a gate region in the neighborhood of the source is removed. Then the nitride film 5 is removed according to CDE using the resist 6 as a mask, and the resist 6 is removed. When RIE is performed moreover, the nitride film 5 is left only at the side wall part of the gate. Then when arsenic ions are implanted using the gate electrode 3 and the nitride film 5 as masks, a high concentration diffusion layer is formed on the source side, a low concentration diffusion layer is formed in the neighborhood of the gate on the drain side, and a high concentration diffusion layer is formed at a part saparated a little from the gate on the drain side. Then after a CVD-SiO2 film 8 is adhered, contact holes are opened, and an Al wiring is patterned to form a gate wiring 9, a source wiring 10 and a drain wiring 11.

Method for forming semiconductor devices

Abstract: A method is disclosed for forming openings in polyimide layers and for thereby forming semiconductor devices. The method allows for the forming of openings having tapered side walls and precise dimensional control. First and second layers of polyimide are sequentially formed on a surface. The first layer, in contact with the surface, is fully cured while the second layer is only partially cured. Overlying the second layer is a masking layer which can alternatively be an inorganic material or a resist material. A pattern is formed in the masking layer to expose portions of the upper polyimide layer. The pattern includes openings of predetermined size having a precise critical dimension. Using the patterned masking layer as an etch mask the upper layer of polyimide is isotropically etched in an etchent which etches the partially cured polyimide but which does not etch the fully cured underlying polyimide. The underlying polyimide layer is then anisotropically etched using the patterned masking layer as an etch mask to form openings in the cured polyimide layer having the same critical dimensions as in the masking layer pattern. The masking layer is then removed and the second polyimide layer is fully cured.

Semiconductor device and manufacture thereof

Abstract: PURPOSE:To prevent the generation of cracks in a protection film by a method wherein the upper cross section of a metallic wiring of a semiconductor device is formed into a trapezoid. CONSTITUTION:An Al film 10 approx. 1mu thick is superposed on the surface 11 of an Si wafer 11, and a resist pattern 13 of approx. 1.5mu wide is provided. After removing the Al film by etching approx. 0.4mu by dipping in an etchant containing phosphoric acid as the main constituent, when reactive ion etching is performed by using CCl4 gas, the Al10 under the resist 13 is vertically removed. When it is covered with a PSG14 by a CVD method after removing the resist 13, the PSG is adhered by forming a gentle slope at a stepwise difference. This constitution enables to prevent the generation of cracks of the protection film 14 without damaging the fineness, and the yield and the reliability improve.