Abstract: A method for pattern-etching thick alumina layers in the manufacture of thin film heads (TFH) by using compatible metallic mask layers and a wet chemical etchant. The deep alumina etching facilitates a studless TFH device where the coil and bonding pads are deposited and patterned simultaneously, and vias are later etched through the alumina overcoat layer to expose the bonding pads. The method also enables the etching of scribe-line grooves of street and alleys across the wafer for sawing and machining of sliders. These grooves eliminate most alumina chipping due to stress and damage introduced by the sawing and machining operations. Similarly, pattern-etching of the alumina undercoat facilitates the formation of precise craters for recessed structures. These can improve planarity and alleviate problems related to adverse topography and elevated features of TFH devices.

Abstract: Method for making a mesh-and-plate surgical implant includes the steps of applying maskant to first and second faces of a metal sheet, selectively ablating the maskant on both faces, affixing a first tape to the first face to cover same and maskant thereon, but leaving an exposed portion for a screw hole, affixing a second tape to the second face to cover same and maskant thereon, etching the first face screw hole portion to form a crater, removing the first tape, etching the crater and other exposed portions of the first face, removing the second tape, etching opposite the crater and other exposed portions of the second face to provide openings in communication with the crater, and other second face openings extending to the first face, and removing remaining maskant to provide the implant configured to include a pliable mesh portion and a rigid plate portion, and having a screw hole therein.

Abstract: A phase shifting mask repair process is described. The process uses an etching gas or a hydrofluoric acid solution to etch the quartz substrate and the characteristics of the phase shifter layer being only slightly etched when clean with a NH3/H2O2/H2O2 solution to calculate and adjust the respective processing time accordingly. As a result, the phase difference between the quartz substrate and the MoSiON phase shifter layer stays relatively the same before and after the repair process.

Abstract: The present invention relates to a novel process for removing sidewall residue after dry-etching process. Conventionally, after dry-etching, photoresist and sidewall residues are removed by ozone ashing and hot sulfuric acid. Normally, they are hard to be removed completely. It was found in the present invention that the addition of fluorine-containing compound, preferably hydrogen fluoride and ammonium fluoride, in sulfuric acid results in complete removal of photoresist and sidewall residue without the need for stripper. The process is simple and does not affect the original procedures or the other films on the substrate. The present invention also relates to a novel solution for removing sidewall residue after dry-etching, which comprises sulfuric acid and a fluorine-containing compound, preferably hydrogen fluoride and ammonium fluoride, in the range of from 10:1 to 1000:1 by weight.

Abstract: The invention includes a method of cleaning a surface of a copper-containing material by exposing the surface to an acidic mixture comprising NO3−, F− and one or more organic acid anions having carboxylate groups. The invention also includes a semiconductor processing method of forming an opening to a copper-containing material. A mass is formed over a copper-containing material within an opening in a substrate. The mass contains at least one of an oxide barrier material and a dielectric material. A second opening is etched through the mass into the copper-containing material to form a base surface of the copper-containing material that is at least partially covered by particles comprising at least one of a copper oxide, a silicon oxide or a copper fluoride. The base surface is cleaned with a solution comprising nitric acid, hydrofluoric acid and one or more organic acids to remove at least some of the particles.

Abstract: An etching treatment agent which can etch insulating film with high speeds without damaging the resist pattern, provide realistic throughput when the insulting film etching process in the semiconductor manufacturing process is replaced with the single wafer processing etching treatment method, and prevent roughness on the surface of the semiconductor after etching.

Abstract: An implantable prosthesis, for example a stent, is provided having one or more micropatterned microdepots formed in the stent. Depots are formed in the prosthesis via chemical etching and laser fabrication methods, including combinations thereof. They are formed at preselected locations on the body of the prosthesis and have a preselected depth, size, and shape. The depots can have various shapes including a cylindrical, a conical or an inverted-conical shape. Substances such as therapeutic substances, polymeric materials, polymeric materials containing therapeutic substances, radioactive isotopes, and radiopaque materials can be deposited into the depots.

Abstract: A method of manufacturing a glass substrate for a magnetic disk. The method includes the step of scrub-etching the glass substrate using a pad in the presence of an acid treatment solution. As the acid treatment solution, hydrofluoric acid is used in a range of 0.01 to 1 wt %. The scrub-etching step is performed at temperatures ranging from 5 to 60° C. for 1 second to 300 seconds. The method produces a substrate that is substantially free of asperity.

Abstract: A method for removing metal cladding adhered to an airfoil, such as a turbine blade, wherein the airfoil comprises a substrate and wherein at least a portion of the cladding is adhered to at least one surface of the substrate of the airfoil. In this method the cladding is treated with a chemical etchant of the metal that the cladding is made of for a period of time sufficient to remove at least the portion of the cladding adhered to the at least one surface of the substrate. The substrate is made of a material that is chemically resistant to the etchant.

Abstract: An electrode plate is formed by a substrate and a plurality of patterned electrodes formed on the substrate. Each patterned electrode has a laminate structure including a first layer of nickel metal formed on the substrate and a second layer of copper formed thereon. The electrode plate may be prepared by a process including a step of etching such a multi-layer metal electrode-forming film formed on a substrate by spraying an etchant downwardly and uniformly onto the substrate while rotating the substrate at a rotation speed sufficient to allow quick liberation of the etchant from the substrate. The metal electrodes can be formed with good adhesion onto the substrate and with good width and thickness accuracy. By incorporating the electrode plate as a pair of substrates sandwiching a liquid crystal, a liquid crystal device free from transmission delay and rounding of voltage waveforms can be provided.

Abstract: Emission of NOx during acid-piclding treatment of metals in an aqueous solution containing at least nitric acid is controlled by the addition of hydrogen peroxide. The addition amount of hydrogen peroxide is minimized to avoid excessive addition by monitoring the potentiostatic electrolytic current of the solution or by combinedly monitoring the potentiostatic electrolytic current and the redox potential of the solution.

Abstract: A method for forming rough surface: first, provide a substrate; then, immerse a surface layer of substrate in a solution which is able to etch surface layer; next, form numerous bubbles in solution such that part of bubbles are located on a surface of surface layer, where surface is contacted with solution; finally, remove solution. The method also could form bubbles in solution before surface layer is immersed in solution, and could perform a dry process after solution is removed. Significantly, this method at least could be used to enhance adhesion of photoresist and increases capacitance of capacitor.

Abstract: Disclosed is a method for forming a shallow trench isolation. A pad oxide layer is formed on a semiconductor substrate. First and second stopping layers are sequentially formed on the pad oxide layer. The second stopping layer, the first stopping layer, the pad oxide layer and the semiconductor substrate are etched to form a second stopping layer pattern, a first stopping layer pattern, a pad oxide layer pattern and a trench. A trench inner wall oxide layer is formed at an inner surface portion of the trench. A nitride layer liner is formed on a resulted structure. A field oxide layer is formed in the trench. By selectively removing the second stopping layer pattern, the first stopping layer pattern is exposed. Then, the first stopping layer pattern is removed. Since the chemical mechanical polishing is stopped at the second stopping layer pattern, the first stopping layer pattern is prevented from erosion when the chemical mechanical polishing process is carried out.

Abstract: A process is described for etching oxide films containing at least one bismuth-containing oxide, in particular a ferroelectric bismuth-containing mixed oxide. A substrate onto which at least one oxide film containing at least one bismuth-containing oxide has been applied is provided. An etching solution containing from 2 to 20% by weight of a fluoride ion donor, from 15 to 60% by weight of nitric acid and from 20 to 83% by weight of water is brought into contact with the substrate so that the etching solution can react with the oxide film. The etching solution is removed from the substrate. The etching solution is also used in a process for structuring bismuth-containing oxide films.

Abstract: A mixed aqueous solution containing HCl with a concentration of 10 to 25% by weight, H2O2 with a concentration of 2 to 5% by weight, and HF with a concentration of 0.01 to 2% by weight or a mixed aqueous solution containing H2SO4 with a concentration of 65 to 82% by weight, H2O2 with a concentration of 4 to 16% by weight, and HF with a concentration of 0.01 to 2% by weight is used as a platinum group impurity recovery liquid. The recovery liquid is dripped onto a silicon substrate surface or a film thereon so as to scan the entire surface of the substrate with the droplets. As a result, the platinum group impurity is dissolved into the recovery liquid, and the platinum group impurity is thus recovered.

Abstract: A method of etching comprising subjecting a material under plasma etching conditions to an etching composition comprising at least an etchant compound having the formula CXHCFZ wherein: x=3, 4 or 5; 2x≧z≧y; and y+z=2x+2; and further including an etching composition which includes said etchant compound and a second material different from the etchant compound that enhances or modifies plasma etching.

Abstract: A three-part etching process is employed to selectively pattern exposed magnetic film layers of a magnetic thin film structure. The magnetic structure to be etched includes at least one bottom magnetic film layer and at least one top film layer which are separated by a tunnel barrier layer. The three-part etching process employs various etching steps that selective removing various layers of the magnetic thin film structure stopping on the tunnel barrier layer. The first etching step selective removes any surface oxide that may be present in the passivating layer that is formed on the top magnetic thin film layer, the second etching step selectively removes portions of the passivating layer and the third etching step selectively removes a portion of the exposed magnetic film layer of the structure stopping on the tunnel barrier layer.

Abstract: The present invention discloses an etching apparatus comprising an etching bath having an etchant; an etchant recycling part in the etching bath; a DI and undiluted etchant supply part for supplying a DI water and a undiluted etchant; an etchant mixing part for mixing the DI water and the undiluted etchant; and an etchant heating part for heating the mixed etchant.

Abstract: A silica glass jig for semiconductor industry, which is does not contaminate semiconductor elements, and generates less cracks and a production method thereof are provided.

Abstract: A thin discontinuous layer of metal such as Au, Pt, or Au/Pd is deposited on a Group III-V material surface. The surface is then etched in a solution including HF and an oxidant for a preferably brief period, as little as a couple seconds to one hour. A preferred oxidant is H2O2. Morphology and light emitting properties of porous Group III-V material can be selectively controlled as a function of the type of metal deposited, doping type, doping level, metal thickness, whether emission is collected on or off the metal coated areas and/or etch time. Electrical assistance is unnecessary during the chemical etching of the invention, which may be conducted in the presence or absence of illumination.

Abstract: There is disclosed an etching solution containing at least hydrofluoric acid, nitric acid and hexafluorosilicic acid wherein the concentration of hexafluorosilicic acid is not less than 10% by weight based on the weight of the etching solution.

Abstract: A surface-micromachined rotatable member formed on a substrate and a method for manufacturing thereof are disclosed. The surface-micromachined rotatable member, which can be a gear or a rotary stage, has a central hub, and an annulus connected to the central hub by an overarching bridge. The hub includes a stationary axle support attached to the substrate and surrounding an axle. The axle is retained within the axle support with an air-gap spacing therebetween of generally 0.3 &mgr;m or less. The rotatable member can be formed by alternately depositing and patterning layers of a semiconductor (e.g. polysilicon or a silicon-germanium alloy) and a sacrificial material and then removing the sacrificial material, at least in part. The present invention has applications for forming micromechanical or microelectromechanical devices requiring lower actuation forces, and providing improved reliability.

Abstract: An inductive pinched-gap thin film head (TFH) device having pole-tips which are in substantial contact along their side-edges, thereby precisely defining a pinched-gap segment. The substantial contact between the pole-tips' side-edges effectively eliminates all flux lines emanating from the edges and corners during the write operation. The write magnetic field is thus precisely confined to across the pinched-gap segment. As a result, the written medium track width is accurately defined by the width of the pinched-gap segment with high degree of magnetization coherency and virtual elimination of the track-edge noise. The improved (medium) signal-to-noise ratio facilitates substantial increase of the track density. Photolithographic definition and etching of the gap-vias to the bottom pole-tip, followed by deposition of the top pole-tip, facilitates precise and consistent control of the width of the pinched-gap segment (and the written track) drawn to ≦1 &mgr;m.

Abstract: A composition and process are described which are useful in treating metal surfaces, which composition comprises an oxidizer, an acid, a corrosion inhibitor, an organic nitro compound and, optionally, a benzotriazole with an electron withdrawing group in the 1-position which electron withdrawing group is a stronger electron withdrawer than a hydrogen group, optionally, a source of adhesion enhancing species selected from the group consisting of molybdates, tungstates, tantalates, niobates, vanadates, isopoly or heteropoly acids of molybdenum, tungsten, tantalum, niobium, vanadium, and combinations of any of the foregoing and optionally but preferably a source of halide ions. The composition and process are useful in increasing the adhesion of metal surfaces to polymeric substances and in preserving said adhesion through temperature variation.

Abstract: The present invention relates to a method of cleaning and drying a semiconductor structure in a modified conventional gas etch/rinse or dryer vessel. In an embodiment of the present invention, a semiconductor structure is placed into a first treatment vessel and chemically treated. Following the chemical treatment, the semiconductor structure is transferred directly to a second treatment vessel where it is rinsed with DI water and then dried. The second treatment vessel is flooded with both DI water and a gas that is inert to the ambient, such as nitrogen, to form a DI water bath upon which an inert atmosphere is maintained during rinsing. Next, an inert gas carrier laden with IPA vapor is fed into the second treatment vessel. After sufficient time, a layer of IPA has formed upon the surface of the DI water bath to form an IPA-DI water interface.

Abstract: A phase shifting mask repair process is described. The process uses an etching gas or a hydrofluoric acid solution to etch the quartz substrate and the characteristics of the phase shifter layer being only slightly etched when clean with a NH3/H2O2/H2O2 solution to calculate and adjust the respective processing time accordingly. As a result, the phase difference between the quartz substrate and the MoSiON phase shifter layer stays relatively the same before and after the repair process.

Abstract: A method for controlled removal of a portion of a diffusion coating from the outer surface of a nickel-containing superalloy article. A diffusion coating typically includes a diffusion layer between an outer aluminide layer and the nickel-containing substrate. The method includes contacting the coated superalloy article in a preselected chemical stripping solution for a preselected period of time sufficient to remove only the outer aluminide layer, without substantially affecting the diffusion layer underlying the outer aluminide layer. After neutralizing the stripping solution, the article can be inspected and repaired as needed. The aluminide outer layer can then be restored in a conventional manner.

Abstract: After a Ta radiation absorber 13 is subjected to reactive ion overetching to form a desired pattern till an upper portion of the SiO2 buffer film 12 is removed, the buffer film 12 is removed by two steps of reactive sputter pre-underetching and final wet etching. In the wet etching, a substrate is rotated while spraying a dilute hydrofluoric acid solution, spray and rotation are ceased, the substrate is illuminated with a light beam to detect regularly reflected light, the detected signal is amplified, differentiated and compared with a reference voltage to detect an etching endpoint, and etching is ceased after a predetermined time has elapsed from the detection of the etching endpoint. At an inspection step, an image of a reflective mask is obtained with a microscope and it is determined that the side etching amount of the buffer film is short if the luminance, at a point of the maximum change rate on a luminance curve around the edge of the Ta radiation absorber 13, is lower than a reference value.

Abstract: A composition comprising bifluoride salts in a somewhat viscous form for roughening glass, ceramic and porcelain surfaces in preparation for refinishing includes: a. bifluoride salts in an amount ranging from 10.0 to 85.0 parts by weight; b. thickener in an amount ranging from 0.1 to 5.0 parts by weight; c. organic solvent in an amount ranging from 2.0 to 20.0 parts by weight; and d. water in an amount ranging from 7.0 to 75.0 parts by weight. A coating of the composition is applied to a substrate, such as those having low surface tensions and to which paint adhesion is difficult. The coating is left in contact with the substrate for a period of time effective to roughen the substrate. The coating is then removed and discarded or alternatively, collected and reused. The substrate after treatment will have a roughened surface from which improved paint adhesion results.

Abstract: A surface-micromachined chain and a microelectromechanical (MEM) structure incorporating such a chain are disclosed. The surface-micromachined chain can be fabricated in place on a substrate (e.g. a silicon substrate) by depositing and patterning a plurality of alternating layers of a chain-forming material (e.g. polycrystalline silicon) and a sacrificial material (e.g. silicon dioxide or a silicate glass). The sacrificial material is then removed by etching to release the chain for movement. The chain has applications for forming various types of MEM devices which include a microengine (e.g. an electrostatic motor) connected to rotate a drive sprocket, with the surface-micromachined chain being connected between the drive sprocket and one or more driven sprockets.

Abstract: A micromachined fluid handling device having improved properties. The valve is made of reinforced parylene. A heater heats a fluid to expand the fluid. The heater is formed on unsupported silicon nitride to reduce the power. The device can be used to form a valve or a pump. Another embodiment forms a composite silicone/parylene membrane. Another feature uses a valve seat that has concentric grooves for better sealing operation.

Abstract: A method of removing a ceramic coating (18), and particularly zirconia-containing thermal barrier coating (TBC) materials such as yttria-stabilized zirconia (YSZ), that has been either intentionally or unintentionally deposited on the surface of a component (10). The method entails subjecting the ceramic coating (18) to an aqueous solution containing an acid fluoride salt, such as ammonium bifluoride (NH4HF2) or sodium bifluoride (NaHF2), and a corrosion inhibitor. The method is capable of completely removing the ceramic coating (18) without removing or damaging the underlying substrate material, which may include a metallic bond coat (16).

Abstract: The present invention relates to methods for controlling the etching rate of CoSi2 layers by adjusting the pH of an HF-based solution to obtain the desired etch rate. The pH of the HF-based solution may be adjusted by adding pH modifying chemicals to the solution. A further aspect of the invention is an improved method for manufacturing Schotky barrier infared detectors employing the controlled etching step. A method for reducing drain induced barrier lowering in an active transistor having a small gate length is also provided.

Abstract: A liquid processing apparatus is capable of uniformly processing substrates by a liquid process. The liquid processing apparatus has a chemical liquid tank (21) containing a processing liquid for processing wafers (W) by a predetermined liquid process, a carrying device (24) provided with a wafer holder (42) capable of holding a plurality of wafers (W) to be subjected to the liquid process in a vertical position, and capable of carrying the wafers (W) between a processing position where the wafers (W) are immersed in the chemical liquid contained in the chemical liquid tank (21) and a position above the processing position, and a cover (50) for covering a space extending over the wafers (W) held on the wafer holder (42) of the carrying device (24) so that any air currents may not be substantially generated in the same space.

Abstract: A method of manufacturing semiconductor devices is provided, including the formation of a conductive plug and the minimizing of the step-height of an interlayer dielectric layer. An etching composition is also provided for such a manufacturing method. The method of manufacturing semiconductor devices includes the steps of forming an insulating layer over a semiconductor substrate, forming contact holes in the insulating layer, forming a conductive layer over the insulating layer to burying the contact holes, rotating the semiconductor substrate, and etching the conductive layer by supplying an etching composition on the rotating semiconductor substrate, and spin-etching the tungsten layer using an etching composition such that the conductive layer remains only inside the contact holes and does not remain over the insulating layer.

Abstract: The present invention relates to an improved oxygen sensor and particularly to oxygen sensors used as exhaust sensors in vehicles. The oxygen sensor, which has an improved lean-rich response time and operability at lower temperatures, has been chemically etched and electrically treated, or chemically etched with a non-hydrofluoric acid solution.

Abstract: A composition for converting asbestos-containing material, covering metal pipes or other metal surfaces, to non-regulated, environmentally benign-materials, and inhibiting the corrosion of the metal pipes or other metal surfaces. The composition comprises a combination of at least two multiple-functional group reagents, in which each reagent includes a Fluro acid component and a corrosion inhibiting compoment. A method for converting asbestos-containing material, covering metal pipes or other metal surfaces, to non-regulated, environmentally benign-materials, and inhibiting the corrosion of the metal pipes or other metal surfaces is also provided.

Abstract: A method of manufacturing semiconductor devices is provided for forming a tungsten plug or polysilicon plug and minimizing the step-height of the intermediate insulating layer. An etching composition for this process is also provided as are semiconductor devices manufactured by this process. The method of manufacturing semiconductor devices includes the steps of forming a tungsten film having a certain thickness on an insulating layer and burying contact holes formed in the insulating layer constituting a specific semiconductor structure, and spin-etching the tungsten film using a certain etching composition such that the tungsten film is present only inside the contact holes not existing on the insulating film. The etching composition includes at least one oxidant selected from the group comprising H.sub.2 O.sub.2, O.sub.2, IO.sub.4.sup.-, BrO.sub.3, ClO.sub.3, S.sub.2 O.sub.8.sup.-, KlO.sub.3, H.sub.5 IO.sub.6, KOH, and HNO.sub.3, at least one enhancer selected from the group comprising HF, NH.sub.4 OH, H.

Abstract: A method for improving etch uniformity during a wet etching process is disclosed. The method comprises the steps of first rinsing the wafer to form a water film over the wafer surface, followed by liquid phase etching. The water film helps the subsequent viscous etchant to be spread across the wafer surface more uniformly to thereby improve the etch uniformity.

Abstract: Solutions useful for etching semiconductor devices comprise ammonium fluoride, hydrofluoric acid, hydrogen peroxide, and water. Processes for forming the solutions comprise mixing first solutions which comprise ammonium fluoride, hydrofluoric acid, and water with second solutions which comprise hydrogen peroxide and water to form the solutions of the invention. Methods for etching semiconductor devices comprise contacting the devices which comprise a substrate and oxide layer thereon with the solutions of the invention to etch the devices. The oxide layer, for example a damaged silicon oxide layer on a silicon substrate, is selectively etched to the substrate.

Abstract: A surface having an exposed silicon/silica interface is cleaned by an HF dip, followed immediately by a rinse in citric acid, followed by a rinse in deionized water. Low pH of the citric acid significantly prevents the formation of a charge differential between the silica and silicon portions of the surface, which charge differential would otherwise cause any silica particles present to remain on the silicon portion of the surface. Surfactant properties of the citric acid help remove any silica particles from the surface. The deionized water rinse then removes the citric acid from the surfaces, leaving a very clean, low particulate surface on both the silica and silicon portions thereof, with little or no etching of the silicon portion.

Abstract: A process for removing metallic material, for instance copper, iron, nickle and their oxides, from a surface of a substrate such as a silicon, silicon oxide or gallium arsenide substrate. The process includes the steps of: a) placing the substrate in a reaction chamber; b) providing in the reaction chamber a gas mixture, the mixture comprising a first component which is fluorine or a fluorine-containing compound, which will spontaneously dissociate upon adsorption on the substrate surface and a second component which is a halosilane compound, the halosilane, and the fluorine if present, being activated by: i) irradiation with UV; ii) heating to a temperature of about 800.degree. C. or higher; or iii) plasma generation, to thereby convert said metallic material to a volatile metal-halogen-silicon compound, and c) removing the metal-halogen-silicon compound from the substrate by volatilization. The process may be used to remove both dispersed metal and bulk metal films or islands.

Abstract: An oxide etchant and method of etching are provided. The etchant includes at least one fluorine-containing compound and at least one auxiliary component selected from the group of a boron-containing compound and a phosphorus-containing compound.

Abstract: A wet chemical process is provided for treating an emitter formed on a substrate of a field emission display, the process comprises applying a solution including hydrogen to the emitter. In one embodiment of the invention, the steps of applying a solution comprises applying a solution of hydrofluoric acid to the emitter.

Abstract: The gate oxide film is prevented from being thinned partially. The semiconductor substrate (wafer) can be etched (processed) under excellent conditions. The impurities on the wafer surface can be analyzed and further reduced. In the first aspect, the substrate is irradiated with ultraviolet rays in contact with an F-containing aqueous solution, so that the oxide film and the substrate can be etched at roughly the same etching speed under excellent controllability without deteriorating the planarization of the substrate. In the second aspect, the substrate is etched by irradiating ultraviolet rays during exposure to an acid aqueous solution, so that surface metallic contamination and particles can be removed without deteriorating the wafer surface roughness. Further, the impurity elements in the outermost surface layer of the wafer can be analyzed at high precision by analyzing elements contained in the acid aqueous solution used for the etching.

Abstract: The invention comprises methods of forming contact openings and methods of forming contacts. In but one implementation, an inorganic antireflective coating material layer is formed over an insulating material layer. A contact opening is etched through the inorganic antireflective coating layer and into the insulating layer. Insulative material within the contact opening is etched and a projection of inorganic antireflective coating material is formed within the contact opening. The inorganic antireflective coating material is etched to substantially remove the projection from the contact opening. The preferred etching to remove the projection is facet etching, most preferably plasma etching. The preferred inorganic antireflective coating material is selected from the group consisting of SiO.sub.x where "x" ranges from 0.1 to 1.8, SiN.sub.y where "y" ranges from 0.1 to 1.2, and SiO.sub.x N.sub.y where "x" ranges from 0.2 to 1.8 and "y" ranges from 0.01 to 1.0, and mixtures thereof.

Abstract: An etchant for etching a glass substrate includes distilled water containing HF of more than 5 vol % and about 5 vol % of alcohol. The HF etches a glass substrate and the alcohol dissolves the residue particles attached to a surface of the substrate to apply the etchant to the total area for uniform thickness and smooth surface.

Abstract: An alumina film, a silicon oxide film, and a silicon nitride film formed on a substrate containing a large amount of alumina are etched by using an etching material in which the concentration of ammonium fluoride, which is a component of BHF, is set low. Etching is performed by using an etching material that is an aqueous solution produced by mixing hydrofluoric acid, ammonium fluoride and water at a weight ratio of x:y:(100-x-y) where x and y satisfy a relationship y<-2x+10 (0<x.ltoreq.5, 0<y.ltoreq.10). 50% hydrofluoric acid on the market and 40% aqueous solution of ammonium fluoride are used.

Abstract: An inductive pinched-gap thin film head (TFH) device having pole-tips which are in substantial contact along their side-edges, thereby precisely defining a pinched-gap segment. The substantial contact between the pole-tips' side-edges effectively eliminates all flux lines emanating from the edges and corners during the write operation. The write magnetic field is thus precisely confined to across the pinched-gap segment. As a result, the written medium track width is accurately defined by the width of the pinched-gap segment with high degree of magnetization coherency and virtual elimination of the track-edge noise. The improved (medium) signal-to-noise ratio facilitates substantial increase of the track density. Photolithographic definition and etching of the gap-vias to the bottom pole-tip, followed by deposition of the top pole-tip, facilitates precise and consistent control of the width of the pinched-gap segment (and the written track) drawn to .ltoreq.1 .mu.m.

Abstract: A surface of a diamond, particularly a diamond window, is treated by depositing a layer of a carbide-forming metal such as titanium, on the surface and thereafter removing the layer. The treatment has the effect of passivating stress surface defects in the diamond such as grain boundaries, twin defects and polishing damage.