Abstract: A invention provides a method of manufacturing a thin film magnetic head is provided, capable of forming a magnetic pole layer as easily as possible. By etching a lower insulating layer and the upper insulating layer by RIE using a fluorine-based gas (CF4 or CHF3) or chlorine-based gas (Cl2 or BCl3), a magnetic pole formation space R1 is formed so as to have a uniform width in an upper insulating layer by and a magnetic pole formation space R2 is formed in the lower insulating layer so as to have a width gradually narrowed from width W1 to width W4 with distance from the magnetic pole formation space R1. After that, a plating film is grown in the magnetic pole formation spaces R1 and R2, thereby forming a main magnetic pole layer.

Abstract: A process for achieving tighter reader and writer track width control is disclosed. The write gap layer is used as the plating seed on which the upper pole is electro-formed. This allows the write gap layer to then be deposited through a precisely controllable process such as sputtering. Since less material needs to be removed during pole trimming, a thinner layer of photoresist may be used, resulting in improved dimensional control.

Abstract: The series resistance of a CPP GMR stack can be reduced by shaping it into a small upper, on a somewhat larger, lower part. Because of the sub-micron dimensions involved, good alignment between these is normally difficult to achieve. The present invention discloses a self-alignment process based on first laying down a mask that will determine the shape of the top part. Ion beam etching is then initiated, the ion beam being initially applied from one side only at an angle to the surface normal. During etching, all material on the near side of the mask gets etched but, on the far side, only material that is outside the mask's shadow gets removed so, depending on the beam's angle, the size of the lower part is controlled and the upper part is precisely centrally aligned above it.

Abstract: A coater having a substrate cleaning device is disclosed. Also disclosed are methods of processing substrates in a coater equipped with a substrate cleaning device. The substrate cleaning device comprises an ion gun (i.e., an ion source) that is positioned beneath a path of substrate travel (e.g., beneath a substrate support) extending through the coater and that is adapted for treating a bottom major surface of a substrate. Certain embodiments involve an upward coating apparatus that is further along the path of substrate travel than the substrate cleaning device. In some embodiments of this nature, the upward coating apparatus is configured for depositing a photocatalytic coating upwardly onto the bottom major surface of the substrate. Certain embodiments of the invention involve a downward coating apparatus, wherein the substrate cleaning device is further along the path of substrate travel than the downward coating apparatus.

Abstract: A solid state nanopore device including two or more materials and a method for fabricating the same. The device includes a solid state insulating membrane having an exposed surface, a conductive material disposed on at least a portion of the exposed surface of the solid state membrane, and a nanopore penetrating an area of the conductive material and at least a portion of the solid state membrane. During fabrication a conductive material is applied on a portion of a solid state membrane surface, and a nanopore of a first diameter is formed. When the surface is exposed to an ion beam, material from the membrane and conductive material flows to reduce the diameter of the nanopore. A method for evaluating a polymer molecule using the solid state nanopore device is also described. The device is contacted with the polymer molecule and the molecule is passed through the nanopore, allowing each monomer of the polymer molecule to be monitored.

Abstract: The present invention provides an apparatus and method for making an apparatus for sensing and/or characterizing a biopolymer translocating a nanopore. The apparatus of the present invention provides a first electrode, a first insulator, a second electrode, a optional insulator, a voltage source for applying a time varying potential difference between the electrodes, and a means of measuring the resulting current between the two electrodes. A method for making the apparatus is also disclosed.

Abstract: A method for protecting a write head coil during write pole notching using ion mill resistant mask formed by reactive ion etching is disclosed. Ion mill shaping of the write pole is performed after depositing an ion mill-resistant material to protect the coil.

Abstract: A head including a write element for writing data to a magnetic media, and methods for its production are provided. A write element of the invention includes one or more of a recessed first pole, a heat sink layer, and a shortened yoke length. A method of the invention provides forming an anti-reflective layer before forming a mask layer. During photolithography the anti-reflective layer suppresses undesirable reflections off of features, such as vertical sidewalls, that otherwise limit how closely to such features portions of the mask layer can be formed.

Abstract: A writing magnetic pole portion composed of a first magnetic film and a second magnetic film formed on the first magnetic film via a gap film is fabricated on a given wafer. Then, the writing magnetic pole portion is swung forward and backward around a rotation standard axis parallel to a center line of the writing magnetic pole portion in a direction parallel to a surface of the. Then, the writing magnetic pole portion is milled during the swing of the writing magnetic pole portion to define the width of the writing magnetic pole portion.

Abstract: A method of producing a stamper, an optical recording medium produced by molding using the stamper, and a method of producing the same, wherein a base member having a mirror polished main surface and comprising silicon or glass is formed with a resist film; the resist film is exposed by a focused electron beam, an ultraviolet ray laser, etc. and developed so as to form a resist film of a pattern corresponding to relief shapes; the mirror surface of the base member is processed to relief shapes (projecting regions and recessed regions) by dry etching etc. using the obtained resist film as a mask so as to obtain a stamper; the obtained stamper is used for injection molding to form a medium substrate; and an optical recording multilayer film and a protective layer are formed to thereby produce an optical recording medium.

Abstract: A method for manufacturing a write head having a small write pole tip that emits magnetic flux sufficient for effective perpendicular recording. The method creates a leading edge taper (LET) between the write pole tip and a magnetic flux guide to create a sufficient magnetic flux in the write pole. The LET is fabricated by ion milling away a sacrificial striated material whose layers have different rates of ion milling. The top layer of material thus mills away faster than lower layers, creating the required tapering of a negative mold. An endpoint material stops the milling. The LET magnetic material is then spattered into the negative mold, resulting in a well defined taper of magnetic flux shaping material extending the magnetic flux guide to the write pole tip, such that the write pole tip is able to emit sufficient magnetic flux for perpendicular recording.

Abstract: The present disclosure relates to a method for generating a three-dimensional microstructure in an object. In one embodiment, a method for fabricating a microscopic three-dimensional structure is provided. A work piece is provided that includes a target area at which the three-dimensional structure is to be fabricated. The target area has a plurality of virtual dwell points. A shaped beam is provided to project onto the work piece. The intersection of the shaped beam with the work piece defines a beam incidence region that has a desired shape. The beam incidence region is sufficiently large to encompass multiple ones of the virtual dwell points. The shaped beam is moved across the work piece such that different ones of the virtual dwell points come into it and leave it as the beam moves across the work piece thereby providing different doses to different ones of the virtual dwell points as the different dwell points remain in the beam incidence region for different lengths of time during the beam scan.

Abstract: A charged particle beam apparatus and method for locally removing material from a predetermined location on a workpiece, such as the removal of a metallization layer covering an alignment mark on a wafer. The invention is particularly suited for high-volume mass production of semiconductor chips or electromechanical devices. According to one embodiment of the invention, a layer of material covering an alignment mark on a wafer is removed by ion beam sputtering using a non-LMIS beam directed at an oblique angle to the sample surface.

Abstract: An etching apparatus comprises a workpiece holder (21) for holding a workpiece (X), a plasma generator (10, 20) for generating a plasma (30) in a vacuum chamber (3), an orifice electrode (4) disposed between the workpiece holder (21) and the plasma generator (10, 20), and a grid electrode (5) disposed upstream of the orifice electrode (4) in the vacuum chamber (3). The orifice electrode (4) has orifices (4a) defined therein. The etching apparatus further comprises a voltage applying unit (25, 26) for applying a voltage between the orifice electrode (4) and the grid electrode (5) to accelerate ions from the plasma (30) generated by the plasma generator (10, 20) and to pass the extracted ions through the orifices (4a) in the orifice electrode (4). A first collimated neutral particle beam is generated and applied to the workpiece (X) for etching a surface of a processing layer (60) of the workpiece (X).

Abstract: A piezoelectric spatial light modulator including a substrate having an array of cavities and piezoelectric cantilevers is arranged on the substrate. Each of the piezoelectric cantilevers includes a base portion on the substrate and a beam portion extending over a respective one of the cavities. Each of the piezoelectric cantilevers further includes a first electrode, a second electrode and a piezoelectric element between the electrodes. A flexible layer covers the cavities and the piezoelectric cantilevers and reflective elements are each located on the flexible layer over a respective one of the beam portions.

Abstract: The method of making a thin-film magnetic head in accordance with the present invention forms a cover layer on an insulating layer about a magnetoresistive film so as to eliminate a protrusion riding on the magnetoresistive film. Then, the protrusion can be eliminated by etching. The part of insulating layer clad with the cover layer is not etched. This can prevent short-circuit from occurring because of thinning the insulating layer.

Abstract: Conventional liftoff processes used to define track width in magnetic read heads can produce an uneven etch-depth of dielectric materials around the sensor and cause shorting to the overlay top lead layer. This problem has been overcome by printing the images of track width and stripe height onto an intermediate layer to form a hard mask. Through this hard mask, the GMR stack can be selectively etched and then back-filled with a high-resistivity material by using newly developed electroless plating processes.

Abstract: A milling device is disclosed for the preparation of microscopy specimens or other surface science applications through the use of ion bombardment. The device provides the ability to utilize both gross and fine modification of the specimen surface through the use of high and low energy ion sources. Precise control of the location of the specimen within the impingement beams created by the ion sources provides the ability to tilt and rotate the specimen with respect thereto. Locational control also permits the translocation of the specimen between the various sources under programmatic control and under consistent vacuum conditions. A load lock mechanism is also provided to permit the introduction of specimens into the device without loss of vacuum and with the ability to return the specimen to ambient temperature during such load and unload operation. The specimen may be observed and imaged during all active phases of operation.

Abstract: A method and materials to fabricate a trailing shield write pole that resolve the problems of controlling the write gap and preventing damages to the write gap or pole during fabrication of the subsequent structure. This process also introduces a CMP assisted lift-off process to remove re-deposition and fencing (increase yields) and a method to create dishing in the top of the write pole. Moreover, also included in this disclosure are suitable materials that can function as an ion mill transfer layer, CMP layer, and RIEable layer.

Abstract: A method for fabricating a current-perpendicular-to-plane (CPP) giant magnetoresistive (GMR) sensor of the synthetic spin valve type is provided, the method including an electron-beam lithographic process employing both primary and secondary electron absorption and first and second self-aligned lift-off processes for patterning the capped ferromagnetic free layer and the conducting, non-magnetic spacer layer. The sensor so fabricated has reduced resistance and increased sensitivity.

Abstract: For controlling a physical dimension of a solid state structural feature, a solid state structure is provided, having a surface and having a structural feature. The structure is exposed to a first periodic flux of ions having a first exposure duty cycle characterized by a first ion exposure duration and a first nonexposure duration for the first duty cycle, and then at a second periodic flux of ions having a second exposure duty cycle characterized by a second ion exposure duration and a second nonexposure duration that is greater than the first nonexposure duration, for the second duty cycle, to cause transport, within the structure including the structure surface, of material of the structure to the structural feature in response to the ion flux exposure to change at least one physical dimension of the feature substantially by locally adding material of the structure to the feature.

Abstract: A method of forming a tunneling magnetoresistive head begins by forming a tunneling magnetoresistive stack having a tunnel barrier. An air bearing surface is formed of the tunneling magnetoresistive stack. The air bearing surface is ion etched causing a deficiency of a constituent in a portion of the tunnel barrier adjacent the air bearing surface. The deficiency of the constituent is replenished in the portion of the tunnel barrier adjacent the air bearing surface to restore the electrical properties of the tunnel barrier.

Abstract: A device serves for reflecting electromagnetic waves, in particular in a length range less than 200 nm. It has a mirror carrier made of a material with at least approximately vanishing thermal expansion and at least one reflective layer applied on said mirror carrier. An intermediate layer made of a material which is formed such that its surface roughness is not significantly increased after beam processing methods is fitted between the mirror carrier and the reflective layer.

Abstract: Apparatus and processes are disclosed for milling copper adjacent to organic low-k dielectric on a substrate by directing a charged-particle beam at a portion of the copper and exposing the copper to a precursor sufficient to enhance removal of the copper relative to removal of the dielectric, wherein the precursor contains an oxidizing agent, has a high sticking coefficient and a long residence time on the copper, contains atoms of at least one of carbon and silicon in amount sufficient to stop oxidation of the dielectric, and contains no atoms of chlorine, bromine or iodine. In one embodiment, the precursor comprises at least one of the group consisting of NitroEthanol, NitroEthane, NitroPropane, NitroMethane, compounds based on silazane such as HexaMethylCycloTriSilazane, and compounds based on siloxane such as Octa-Methyl-Cyclo-Tetra-Siloxane. Products of the processes are also disclosed.

Abstract: The method of making a magnetic head assembly includes forming a second pole piece layer that is recessed from a head surface, forming a reactive ion etchable (RIEable) pole tip forming layer on the second pole piece layer, forming an adhesion/stop layer of tantalum (Ta) on the pole tip forming layer, forming a photoresist mask on the adhesion/stop layer with an opening for patterning the adhesion/stop layer and the pole tip forming layer with another opening, reactive ion etching (RIE) through the opening to form the other opening, forming the second pole piece pole tip in the other opening with a top which is above a top of the adhesion/stop layer and chemical mechanical polishing (CMP) the top of the second pole piece pole tip until the CMP contacts the adhesion/stop layer. The invention also includes the magnetic head made by such a process.

Abstract: Methods of making a read head with improved contiguous junctions are described. After sensor layer materials are deposited over a substrate, a lift-off mask is formed over the sensor layer materials in a central region which is surrounded by end regions. Ion milling is performed with use of the lift-off mask such that the sensor layer materials in the end regions are removed and those in the central region remain to form a read sensor. A high-angle ion mill (e.g. between 45–80 degrees) is then performed to remove redeposited material from side walls of the lift-off mask. Next, a reactive ion etch (RIE) is used to reduce the thickness and the width of the lift-off mask and to remove capping layer materials from the top edges of the read sensor. With the reduced-size lift-off mask in place, hard bias and lead layers are deposited adjacent the read sensor as well as over the mask.

Abstract: A method of repairing a semiconductor chip containing copper is taught, whereby copper is selectively removed from the chip. The method involves processing the chip inside a chamber in which the chip is exposed to various gases and an energy source, such as a focused ion beam. To the extent the chip may have non-copper materials, such as nitride and oxide layers, on top of the copper that is to be removed, those non-copper materials will first be selectively removed. Such removal typically results in a hole (a so-called “elevator shaft”) leading to the copper that is to be removed. Next, the method teaches the introduction of a combination of nitrogen and oxygen into the chamber and the directing of the ion beam at the spot where the copper is to be removed. In this manner, the copper on the chip is cleanly and reliably removed, without causing damage to the processing chamber.

Abstract: A method for reducing noise in a lapping guide. Selected portions of a Giant magnetoresistive device wafer are masked, thereby defining masked and unmasked regions of the wafer in which the unmasked regions include lapping guides. The wafer is bombarded with ions such that a Giant magnetoresistive effect of the unmasked regions is reduced.

Abstract: An apparatus and method of machining sliders to obtain the optimum PTR for each slider. An array of MEMS devices configured for angular actuation are provided, and a slider is placed in each MEMS device of the array. The ion milling of the sliders is controlled individually for each slider based on the relationship of the ion angle and relative etch rates of the slider components. The MEMS devices are controlled to ensure the ion incidence angle for each slider is such that the desired PTR of each slider is achieved.

Abstract: A stamper suppressed in surface roughness, uneven thickness, and deviation of circularity in inner circumference, a method of producing the same, an optical recording medium produced by molding using the stamper, and a method of producing the same, wherein a base member having a mirror polished main surface and comprising silicon or glass is formed with a resist film; the resist film is exposed and developed so as to form a resist film of a pattern corresponding to relief shapes; the mirror surface of the base member is processed to relief shapes (projecting regions and recessed regions) by dry etching etc. using the obtained resist film as a mask so as to obtain a stamper; the obtained stamper is used for injection molding to form a medium substrate; and an optical recording multilayer film and a protective layer are formed to thereby produce an optical recording medium.

Abstract: A method for forming a trimmed upper pole piece for a magnetic write head, said pole piece having a tapered profile that is widest at its trailing edge. Such a pole piece is capable of writing narrow tracks with sharply and well defined patterns and minimal overwriting of adjacent tracks. The present method produces the necessary taper by using NiCr, NiFeCr, Rh or Ru as write gap filling materials which have an etch rate which is substantially equal to the etch rate of the other layers forming the pole piece and are highly corrosion resistant. As a result, the write gap does not protrude to mask the effects of the ion-beam etch used to form the taper.

Abstract: A method and system for registering a CAD layout to a Focused Ion Beam image for through-the substrate probing, without using an optical image and without requiring biasing, includes an improved method of trench endpointing during the FIB milling operation with a low beam energy. The method further includes removal of Ga at the trench floor using XeF2, as well as the deposition of an insulating layer onto the trench floor.

Abstract: In order to establish processing techniques capable of making multi-tip probes with sub-micron intervals and provide such microscopic multi-tip probes, there is provided an outermost surface analysis apparatus for semiconductor devices etc. provided with a function for enabling positioning to be performed in such a manner that there is no influence on measurement in electrical measurements at an extremely small region using this microscopic multi-tip probe, and there are provided the steps of making a cantilever 1 formed with a plurality of electrodes 3 using lithographic techniques, and forming microscopic electrodes 6 minute in pitch by sputtering or gas-assisted etching a distal end of the cantilever 1 using a focused charged particle beam or using CVD.

Abstract: A Focused Ion Beam (FIB) milling end-point detection system uses a constant current power supply to energize an Integrated Circuit (IC) that is to be modified. The FIB is cycled over a conductive trace that is to be accessed during the milling process. The input power, or voltage to the IC is monitored during the milling process. The end-point can be detected when the FIB reaches the conductive trace. The FIB can inject charge onto the conductive trace when the FIB reaches the level of the conductive trace. An active device coupled to the conductive trace can amplify the charge injected by the FIB. The active device can operate as a current amplifier. The change in IC current can result in an amplified change in device input voltage. The end-point can be detected by monitoring the change in input voltage from the constant current power supply.

Abstract: At least one strippable film on a surface of a thin film to be patterned is formed, then the at least one strippable film and the thin film to be patterned is patterned by using FIB, and thereafter the at least one strippable film is removed.

Abstract: A method for minimizing damage to a substrate while repairing a defect in a phase shifting mask for an integrated circuit comprising locating a bump defect in a phase shifting mask, depositing a first layer of protective coating to an upper surface of the bump defect, depositing a second layer of protective coating to areas of the phase shifting mask adjacent the bump defect, etching the first layer of protective coating and removing the bump defect.

Abstract: Method and apparatus for reducing the curvature of a micromachined structure having lamella (12). Surface treatment by an ion beam (30) of the lamella (12) such as by sputtering removes regions of stress allowing the lamella (12) to return to a planar condition. The resulting outer surface is made suitable for use as a reflector and other purposes needing a substantially planar surface.

Abstract: A method for tuning an electro-mechanical device such as a MEMS device is disclosed. The method comprises operating a MEMS device in a depressurized system and using FIB micromachining to remove a portion of the MEMS device. Additionally, a method for tuning a plurality of MEMS devices by depositing an active layer and then removing a portion of the active layer using FIB micromachining. Also, a method for tuning a MEMS device and vacuum packaging the MEMS device in situ are provided.

Abstract: A recording medium manufacturing method has a surface treatment process which removes contamination from a surface of a thermoplastic resin support substrate and also improves its wettability. This surface treatment process is conducted prior to forming the layer structure, which includes at least a signal recording layer, onto the surface of the thermoplastic resin support substance. The support substance is placed in an active gas atmosphere, such as ozone, followed by an inert gas atmosphere, such as nitrogen. This surface treatment process generates little deterioration in the support substrate surface.

Abstract: A method for forming a trimmed upper pole piece for a magnetic write head, said pole piece having a uniform width above and below a write gap layer. Prior art methods of trimming pole pieces to a final width using ion-beam etches produce pole pieces with thickness differentials due to the etch resistant nature of the alumina write-gap filling material. The present method uses NiCr, NiFeCr or Ru as write gap filling materials which have an etch rate which is substantially equal to the etch rate of the other layers forming the pole piece and are highly corrosion resistant.

Abstract: A method of improving focused ion beam milling particularly suitable for uniformly removing multiple layers of conductor and dielectric, such as the removal of multiple layers consisting of dummy copper pads and SiO2 on a semiconductor device. Variable Pixel Milling is first used to more uniformly remove most of a layer of conductor and dielectric. The use of Variable Pixel Milling may also be used in conjunction with a technique whereby incoming ions pass through a sacrificial layer formed on the surface of the layer being removed in order to further increase uniformity of material removal. Focused ion beam sputtering in conjunction with an oxygen containing gas, such as H2O vapor or oxygen, is then used to smooth out the trench floor before the next layer is removed.

Abstract: Regardless of the materials used in an artificial joint component design, the present invention applies gas cluster ion beam (GCIB) technology in order to modify the component's surface(s) so as to increase lubrication between contact surfaces, thereby substantially reducing wear debris, osteolysis complications, and accelerated wear failure. The approach of the surface modification comprises an atomic level surface patterning utilizing GCIB to apply a predetermined pattern to the surface(s) of the joint implant to reduce frictional wear at the interface of the surfaces. A reduction in wear debris by GCIB patterning on any surface(s) of a joint prosthesis reduces accelerated failure due to wear and osteolysis and results in a substantial cost savings to the healthcare system, and reduces patient pain and suffering.

Abstract: A method of manufacturing a thin film magnetic head capable of improving a yield while making a pole width extremely minute with high precision is provided. A write gap layer and a bottom pole are selectively etched in a region other than a portion corresponding to a front end part through the RIE with the front end part having an extremely minute uniform width as a mask in an atmosphere of gas including at least chlorine out of chlorine and boron trichloride and at an ambient temperature within a range of 30° C. to 300° C. The width (pole width) of a pole portion can be made uniform with high precision along a length direction so that the yield of the thin film magnetic head can be improved.

Abstract: A method of constructing an air bearing on a single slider used as a support for a magnetic recording head is described. A recessed surface of the air bearing is constructed by: applying a polymerization initiator (preferably azomonochlorsilane), forming a pattern in the initiator, forming a polymer brush, and ion milling. The application of the polymerization initiator may be from solution or by stamping.

Abstract: A micro-machining process that includes etching a substrate having copper overlying a dielectric layer to a charged particle beam in the presence of an etch assisting agent. The etch assisting agent is selected from the group consisting of ammonia, acetic acid, thiolacetic acid, and combinations thereof.

Abstract: For machine parts, cutting tools and molds used under extremely high contact pressures, an amorphous carbon film is provided which has a sufficient adhesion to a substrate. The amorphous carbon covered member has an interlayer comprising at least one element selected from the group consisting of elements in the IVa, Va, VIa and IIIb groups and the IVb group except carbon in the periodic table, or a carbide of at least one element selected from the group, and an amorphous carbon film formed on the interlayer. The interlayer has a thickness of 0.5 nm or over and less than 10 nm.

Abstract: A method for repairing a defective photomask having contained therein a minimum of one defect within a defective pattern employs a non-defective photomask for purposes of photoexposing a photoresist layer formed upon the defective photomask such as to form a patterned photoresist layer which leaves exposed the minimum of one defect. The minimum of one defect may then be repaired with the patterned photoresist layer in place as a repair mask. The method also provides for use of a non-defective pattern region within a defective photomask in a like fashion for repairing a defective pattern region within the same photomask. The method may be extended to repairing defective microelectronic products.

Abstract: In conjunction with sputtering a metal, especially copper, into high aspect-ratio holes in a wafer, an oblique ion milling method in which argon ions or other particles having energies in the range of 200 to 1500 eV are directed to the wafer at between 10 and 35° to the wafer surface to sputter etch material sputter deposited preferentially on the upper corners of the holes. The milling may be performed in the sputter deposition chamber either simultaneously with the deposition or after it or performed afterwards in a separate milling reactor. A plurality of ion sources arranged around the chamber improve angular uniformity or arranged axially improve radial uniformity or vary the angle of incidence. An annular ion source about the chamber axis allows a plasma current loop. Anode layer ion sources and sources composed of copper are advantageous.

Abstract: This invention relates to a method of making a window (e.g., vehicle windshield, architectural window, etc.), and the resulting window product. At least one glass substrate of the window is ion beam treated and/or milled prior to application of a coating (e.g., sputter coated coating) over the treated/milled substrate surface and/or prior to heat treatment. As a result, defects in the resulting window and/or haze may be reduced. The ion beam used in certain embodiments may be diffused. In certain embodiments, the ion beam treating and/or milling is carried out using a fluorine (F) inclusive gas(es) and/or argon/oxygen gas(es) at the ion source(s). In certain optional embodiments, F may be subimplanted into to treated/milled glass surface for the purpose of reducing Na migration to the glass surface during heat treatment or thereafter, thereby enabling corrosion and/or stains to be reduced for long periods of time.

Abstract: Ion texturing methods and articles are disclosed.