Abstract: A method is provided of smoothing the perturbations on a surface, in particular the surface of a magnetic head slider, the method comprising several steps. At least one air-bearing surface to be smoothed is exposed to an ion species generated from a defined source to form a beam of incident radiation. The beam has a linear axis emanating from the source and thus forms an angle of incident radiation with respect to the surface to be smoothed. The at least one surface is smoothed by exposing the surface(s) to be smoothed to the beam of incident radiation, where the angle of incident radiation is less than 90° relative to a vertical axis drawn perpendicular to the surface to be smoothed. To make a corrosion resistant magnetic head slider, the method further comprises coating the smoothed surface with a layer of amorphous carbon.

Abstract: An apparatus for masked ion-beam lithography comprises a mask maintenance module for prolongation of the lifetime of the stencil mask. The module comprises a deposition means for depositing material to the side of the mask irradiated by the lithography beam, with at least one deposition source being positioned in front of the mask, and further comprises a sputter means in which at least one sputter source, positioned in front of the mask holder means and outside the path of the lithography beam, produces a sputter ion beam directed to the mask in order to sputter off material from said mask in a scanning procedure and compensate for inhomogeneity of deposition.

Abstract: A solid state structure having a surface is provided and exposed to a flux, F, of incident ions under conditions that are selected based on: ∂ ∂ t ⁢ C ⁡ ( r , t ) = F ⁢   ⁢ Y 1 + D ⁢ ∇ 2 ⁢ C - C τ trap - F ⁢   ⁢ C ⁢   ⁢ &sigm

Abstract: First electrode layers are formed on second antiferromagnetic layers, and in a step separate from the above, second electrode layers are formed above internal end surfaces of the second antiferromagnetic layers and the first electrode layers and parts of the upper surface of the multilayer film with an additional film provided therebetween. Since the first and the second electrode layers are formed separately, it is not necessary to perform mask alignment twice, and hence an overlap structure can be precisely formed in which the thickness of the second electrode layer at the left side is equivalent to that at the right side.

Abstract: A magnetic read head with reduced side reading characteristics is described. This design combines use of a current channeling layer (CCL) with stabilizing longitudinal bias layers whose magnetization direction is canted relative to that of the free layer easy axis and that of the pinned layer (of the GMR). This provides several advantages: First, the canting of the free layer at the side region results in a reduction of side reading by reducing magnetic sensitivity in that region. Second, the CCL leads to a narrow current flow profile at the side region, therefore producing a narrow track width definition. A process for making this device is described. Said process allows some of the requirements for interface cleaning associated with prior art processes to be relaxed.

Abstract: System for frequency adjustment of piezoelectric resonators by ion etching in vacuum, based on arranging the resonators in rows and columns on a tray that can be moved to simultaneously expose two rows of resonators to the two straight-track portions of an ion gun having a race-track-shaped beam pattern whose straight tracks are spaced at an integer multiple of the inter-row spacing d. As the tray is moved in steps of d, two rows can be etched simultaneously, and each row can be sequentially exposed to a “pre-etch” and “final-etch” stage, with time between the two stages for the resonators to cool down after the “pre-etch” stage.

Abstract: A method and an apparatus have been developed to fabricate large area uniform silicon cone arrays using different kinds of ion-beam sputtering methods. The apparatus includes silicon substrate as the silicon source, and metal foils are used as catalyst. Methods of surface modification of the as-synthesized silicon cones for field emission application have also been developed, including hydrofluoric acid etching, annealing and low work-function metal coating. Nano-structure modification based on silicon cones takes advantage of the fact that the cone tip consists of metal/metal siliside, which can be used as catalyst and template for nanowires growth. A method and an apparatus have been developed to grow silicon oxide/silicon nanowires on tips of the silicon cones.

Abstract: A plate assembly on which a wafer is supported in the processing chamber of a processing apparatus facilitates a precise transfer of the wafer therefrom even when a vacuum atmosphere is present in the chamber. The plate assembly includes an underlying support plate and a pad dedicated to support the rear surface of the wafer. A plurality of recesses, in the form of parallel grooves, extend in the upper surface of the pad so that the rear surface of the wafer can also be exposed to the vacuum atmosphere in the processing chamber. Accordingly, a pressure difference at both sides of the wafer is minimized. Thus, the wafer can be raised off of the plate assembly while the precise position thereof is maintained.

Abstract: A method of manufacturing an electrode for a secondary battery by depositing a thin film composed of active material on a current collector in which a surface-treated layer such as an antirust-treated layer is formed, including the steps of: removing at least part of the surface-treated layer by etching the surface of the current collector with an ion beam or plasma in order to improve the diffusion of the current collector material into the active material thin film; and depositing the thin film on the surface of the current collector subjected to the etching step.

Abstract: This invention relates to a method of making a laminated window such as a vehicle windshield. At least one of the two glass substrates of the window is ion beam milled prior to heat treatment and lamination. As a result, defects in the resulting window and/or haze may be reduced.

Abstract: A method of manufacturing a thin film magnetic head includes forming a recording gap layer of a non-alumina base nonmagnetic material on a lower magnetic pole layer, the lower magnetic pole layer being composed of materials that are milled at the same rate. An upper magnetic pole layer is formed on the recording gap layer, and a single piece of equipment is used to trim the lower magnetic pole layer and pattern the recording magnetic gap layer such that the lower magnetic pole layer has a width that is substantially the same as that of the upper magnetic pole layer. The recording gap layer and the upper and lower half-gap layers are then removed over a region of the underlying substrate. Prescribed areas of tan air-bearing surface (ABS) are then etched to form a slider shape having a protruding part and a depressed part, the ABS and the side surface having a common edge such that the depressed part along the common edge extends into, but not beyond, the region.

Abstract: A method of repairing opaque defects in lithography masks entails focused ion beam milling in at least two steps. The first step uses a large pixel spacing to form multiple holes in the defect material, with the milled area extending short of the defect material edge. The final step uses a pixel spacing sufficiently close to produce a smooth floor on the milled area, and extends to the edge of the defect. During the second step, an etch enhancing gas such as bromine is preferably used.

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: Numerous studies suggest that the current popular designs of coronary stents are functionally equivalent and suffer a 16 to 22 percent rate of restenosis. Although the use of coronary stents is growing, the benefits of their use remain controversial in certain clinical situations or indications due to their potential complications. The application of gas cluster ion beam (GCIB) surface modification such as smoothing or cleaning appears to reduce these complications and lead to genuine cost savings and an improvement in patient quality of life. The present invention is directed to the use of GCIB surface modification to overcome prior problems of thrombosis and restenosis. The atomic level surface smoothing of stents utilizing GCIB substantially reduces undesirable surface micro-roughness in medical coronary stents.

Abstract: Methods for fabricating a highly effective, micron-scale micro heat barrier structure and process for manufacturing a micro heat barrier based on semiconductor and/or MEMS fabrication techniques. The micro heat barrier has an array of non-metallic, freestanding microsupports with a height less than 100 microns, attached to a substrate. An infrared reflective membrane (e.g., 1 micron gold) can be supported by the array of microsupports to provide radiation shielding. The micro heat barrier can be evacuated to eliminate gas phase heat conduction and convection. Semi-isotropic, reactive ion plasma etching can be used to create a microspike having a cusp-like shape with a sharp, pointed tip (<0.1 micron), to minimize the tip's contact area. A heat source can be placed directly on the microspikes. The micro heat barrier can have an apparent thermal conductivity in the range of 10−6 to 10−7 W/m-K. Multiple layers of reflective membranes can be used to increase thermal resistance.

Abstract: A method of texturing the surface of a CSS/landing zone of a substrate for a magnetic recording medium, comprising steps of: (a) providing a disk-shaped substrate having a surface; (b) providing a patterned mask in overlying relation to the substrate surface, (c) selectively implanting ions in portions of the surface of the CSS/landing zone exposed by the patterned mask openings, whereby the height of the selectively ion-implanted portions is increased or decreased relative to the height of non-ion-implanted portions of the CSS/landing zone to form bumps or depressions, thereby providing the surface of the CSS/landing zone with a texture for reducing stiction and friction when the medium is used with a low flying height read/write transducer. Embodiments of the invention include hard disk magnetic recording media with textured CSS/landing zones produced by the inventive ion implation methodology.

Abstract: The invention includes methods of forming magnetoresistive devices. In one method, a construction is formed which includes a first magnetic layer, a non-magnetic layer over the first magnetic layer, and a second magnetic layer over the non-magnetic layer. A first pattern is extended through the second magnetic layer and to the non-magnetic layer with an etch selective for the material of the second magnetic layer relative to the material of the non-magnetic layer. A dielectric material is formed over the patterned second magnetic layer, and subsequently a second etch is utilized to extend a second pattern through the non-magnetic layer and at least partway into the first magnetic layer.

Abstract: The invention includes a method of forming a magnetoresistive device. A stack is formed. The stack comprises a first magnetic layer, a second magnetic layer, and a non-magnetic layer between the first and second magnetic layers. At least one of the first magnetic layer, second magnetic layer, and non-magnetic layer is etched with a primarily physical etch process in a reaction chamber to expose a portion of the etched layer. While the stack remains in the reaction chamber, a protective material is deposited over the exposed portion.

Abstract: A method of making read sensor with self-aligned low resistance leads is provided. In the method a masking step has been eliminated by employing first, second and third protective capping layers in the construction of the read sensor and first and second lead layers. The first capping layer serves as a protective layer for the read sensor sites, the second capping layer protects low resistance lead layer portions during removal of the first capping layer from high resistance lead layer sites and then serves as a sacrificial layer during removal of spin valve material from the low resistance lead layer sites. The third capping layer protects the first and second lead layers during milling of low resistance lead layer material in field regions about the read sensor and first and second lead layers. The method aligns front edges of the low resistance lead layer portions with a rear edge of the read sensor so as to lower the overall resistance of the lead layers.

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: A method and apparatus for gas cluster ion beam (GCIB) processing uses X-Y scanning of the workpiece relative to the GCIB. A neutralizer reduces surface charging of the workpiece by the GCIB. A single Faraday cup sensor is used to measure the GCIB current for dosimetry and scanning control and also to measure and control the degree of surface charging that may be induced in the workpiece during processing.

Abstract: A charged particle beam uniformly removes material, particularly crystalline material, from an area of a target by compensating for or altering the crystal orientation or structure of the material to be removed. The invention is particularly suited for FIB micromachining of copper-based crystalline structures. Uniformity of material removal can be improved, for example, by passing incoming ions through a sacrificial layer formed on the surface of the material to be removed. The sacrificial layer is removed along with the material being milled. Uniformity of removal can also be improved by changing the morphology of the material to be removed, for example, by disrupting its crystal structure or by altering its topography.

Abstract: A read sensor and method of making the same using an etch-stop layer are disclosed. The method is particularly suitable in connection with techniques requiring the partial removal of the capping layer, such as exchange tab (ET) and lead overlay (LOL) techniques. Basically, a thin “etch-stop” layer is deposited over a top free layer of sensor materials. The etch-stop layer is made of a suitable material such as copper oxide (CuO) or nickel-iron-chromium (NiFeCr). A tantalum (Ta) capping layer is then deposited over the etch-stop layer. When appropriate, top edge portions of the capping layer are exposed to a reactive ion etch (RIE) using a fluorine gas for removal. Advantageously, the etch-stop layer significantly reduces or eliminates damage to the free layer that would otherwise occur due to the fluorine gas RIE.

Abstract: An ion-assisted deposition technique to provide planarization of topological defects, e.g., to mitigate the effects of small particle contaminants on reticles for extreme ultraviolet (EUV) lithography. Reticles for EUV lithography will be fabricated by depositing high EUV reflectance Mo/Si multilayer films on superpolished substrates and topological substrate defects can nucleate unacceptable (“critical”) defects in the reflective Mo/Si coatings. A secondary ion source is used to etch the Si layers in between etch steps to produce topological defects with heights that are harmless to the lithographic process.

Abstract: A method and apparatus is disclosed that provided for the successful and precise smoothing of conductive films on insulating films or substrates. The smoothing technique provides a smooth surface that is substantially free of scratches. By supplying a source of electrons, harmful charging of the films and damage to the films are avoided.

Abstract: A magnetoresistance effect device of the present invention includes a multilayer film. The multilayer film includes an antiferromagnetic film, a first ferromagnetic film, a non-magnetic film and a second ferromagnetic film, which are provided in this order on a non-magnetic substrate directly or via an underlying layer. The antiferromagnetic film comprises an &agr;-Fe2O3 film. A surface roughness of the multilayer film is about 0.5 nm or less.

Abstract: A method is provided for grading the surface topography of a surface to improve step coverage for an overcoat. In accordance with one aspect of the present invention, an ABS of a slider and sensitive element of a magnetic head is graded to provide better step coverage of an overcoat of ultra-thin DLC film. After lapping the ABS, a thin film is deposited on the lapped surface to cover any scratches, irregularities, and steps. The thin film is sputter etched at a glancing angle to grade the topography of the slider ABS. Sputtering at a glancing angle removes the thin film in planar regions faster than the thin film under the shadow of the glancing angle, which is near surface irregularities. The graded surface is then covered by a DLC deposition.

Abstract: Substrate removal from a semiconductor chip having silicon-on-oxide (SOI) structure is enhanced via a method and system that provide a control for the removal process. According to an example embodiment of the present invention, a portion of substrate is removed from the back side of a semiconductor chip having a SOI structure and a backside opposite a circuit side. As the substrate is removed, secondary ions are sputtered from the back side. The sputtered ions are detected, and the substrate removal is controlled as a function of detected ions. In this manner, the portion of the substrate being removed can be detected and used to enhance the control of the substrate removal process, such as by detecting sputtered ions from the insulating portion of the SOI and using the insulating portion as an endpoint of the substrate removal process.

Abstract: A recording film is formed on a surface of a substrate, including the slopes, which are positioned on both sides of each information track and have surfaces not parallel to the surfaces of the information tracks. The surface of the substrate is sputter-etched by accelerated ions impinging against the substrate surface in a substantially vertical direction. The recording film on each slope is etched away based on the dependence of a sputtering rate upon an incident angle of the ions, while the recording film remains on the surface of each information track.

Abstract: A mask pattern of a phase shift mask for use in photolithography is repaired. First, an imaginary correction pattern is devised according to the pattern of a mask layer that is disposed on the surface of a transparent plate constituting the body of the mask. The surface of the mask body is etched to a predetermined depth according to the imaginary correction pattern, at a location adjacent the mask layer, to thereby form a recess in the mask body. A phase shifter having a predetermined thickness is then formed by depositing phase shifting material in the recess.

Abstract: A solid state structure having a surface is provided and is exposed to a flux, F, of incident ions.

Abstract: The present invention provides apparatus and methods to carry out the task of both reducing the surface roughness (smoothing) and improving the thickness uniformity of, preferably, but not limited thereto, the top silicon film of a silicon-on-insulator (SOI) wafer or similar thin-film electronic and photonic materials (workpiece). It also provides a method and apparatus for smoothing the surface of a (preferably) SOI wafer (workpiece) and for making the surface of the silicon film of a (preferably) SOI wafer cleaner and more free from contaminants.

Abstract: Disclosed is a system and method for forming a current-perpendicular-to-plane (CPP) spin-valve sensor with one or more metallic oxide barrier layers in order to provide a low junction resistance and a high GMR coefficient. In disclosed embodiments, the metallic oxide barrier layers are formed with oxygen-doping/in-situ oxidation processes comprising depositing a metallic film in a first mixture of argon and oxygen gases and subsequent in-situ oxidization in a second mixture of argon and oxygen gases. The exposure to oxygen may be conducted at a low partial oxygen pressure and at a moderate temperature. Smaller, more sensitive CPP spin-valve sensors may be formed through the use of the oxygen-doping/in-situ oxidization processes of the present invention, thus allowing for greater densities of disk drive systems.

Abstract: A photomask includes a mask substrate formed of a transparent nonconductor, a plurality of opaque conductive patterns formed on the mask substrate and separated from one another, and one or more conductive lines for connecting one of the conductive patterns with at least one adjacent conductive patterns. Electric charges, which accumulate in conductive patterns when using a focused ion beam (FIB) system, are dispersed through the conductive lines. The contrast of images of photomask patterns is increased by dispersion of electric charges, thereby improving the images of photomask patterns.

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: A collimating grid for an ion source located after the exit grid. The collimating grid collimates the ion beamlets and disallows beam spread and limits the beam divergence during transients and steady state operation. The additional exit or collimating grid prevents beam divergence during turn-on and turn-off and prevents ions from hitting the periphery of the target where there is re-deposited material or from missing the target and hitting the wall of the vessel where there is deposited material, thereby preventing defects from being deposited on a substrate to be coated. Thus, the addition of a collimating grid to an ion source ensures that the ion beam will hit and be confined to a specific target area.

Abstract: A diffraction grating is fabricated by forming two sets of parallel trenches in a crystal surface, one set with a crystalline-independent etching technique and the other made with a chemically crystalline-dependent etchant. The intersection of the two sets of trenches removes material from the crystal surface to produce an etched crystal surface that can be coated with a reflective material to form the diffraction grating or can be used as a master for batch fabrication of diffraction gratings.

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 system for monitoring and/or controlling an etch process associated with a dual damascene process via scatterometry based processing is provided. The system includes one or more light sources, each light source directing light to one or more features and/or gratings on a wafer. Light reflected from the features and/or gratings is collected by a measuring system, which processes the collected light. The collected light is indicative of the etch results achieved at respective portions of the wafer. The measuring system provides etching related data to a processor that determines the desirability of the etching of the respective portions of the wafer. The system also includes one or more etching devices, each such device corresponding to a portion of the wafer and providing for the etching thereof. The processor produces a real time feed forward information to control the etch process, in particular, terminating the etch process when desired end points have been encountered.

Abstract: A process for milling copper metal from a substrate having an exposed copper surface includes absorbing a halogen gas onto the exposed copper surface to generate reaction products of copper and the halogen gas; removing unreacted halogen gas from the surface; and directing a focused ion beam onto the surface to selectively remove a portion of the surface comprising the reaction products.

Abstract: The application of gas cluster ion beam (GCIB) technology in order to modify the surface of a surgical implant such as the components of an artificial hip joint, thereby substantially reducing wear debris and osteolysis complications is disclosed. The approach of the surface modification comprises an atomic level surface smoothing utilizing GCIB to super smooth the femoral heads and/or the surfaces of the acetabular cups to reduce frictional wear at the interface of the bearing surfaces. A reduction in polyethylene debris and metal debris by GCIB smoothing on one or both bearing surfaces of a surgical implant reduces osteolysis, results in a substantial cost savings to the healthcare system, and reduces patient pain and suffering.

Abstract: A system of coupling optical energy in a waveguide mode, into a resonator that operates in a whispering gallery mode. A first part of the operation uses a fiber in its waveguide mode to couple information into a resonator e.g. a microsphere. The fiber is cleaved at an angle &PHgr; which causes total internal reflection within the fiber. The energy in the fiber then forms an evanescent field and a microsphere is placed in the area of the evanescent field. If the microsphere resonance is resonant with energy in the fiber, then the information in the fiber is effectively transferred to the microsphere.

Abstract: Thin films of single crystal-like materials are made by using flow-through ion beam deposition during specific substrate rotation around an axis in a clocking action. The substrate is quickly rotated to a selected deposition position, paused in the deposition position for ionized material to be deposited, then quickly rotated to the next selected deposition position. The clocking motion can be achieved by use of a lobed cam on the spindle with which the substrate is rotated or by stopping and starting a stepper motor at long and short intervals. Other symmetries can be programmed into the process, allowing virtually any oriented inorganic crystal to be grown on the substrate surface.

Abstract: A method is provided for a repetitive deposition and etch of a substrate using a carbon containing ion beam in a gridded ion source. The method includes the actual ion beam processing step combined with the thermal and chemical conditioning of the ion source and a special cleaning step(s). The special cleaning step(s) effect robust removal of the precipitates accumulated in the operating source due to the decomposition of carbon containing gases such as hydrocarbons and halocarbons Precipitate removal is achieved by employing ions and radicals formed in an inert gas plasma or a mixture of inert gas and oxygen to reactively etch or bombard the precipitates.

Abstract: There is provided controlled fabrication of a solid state structural feature on a solid state structure by exposing the structure to a fabrication process environment the conditions of which are selected to produce a prespecified feature in the structure. A physical detection species is directed toward a designated structure location during process environment exposure of the structure, and the detection species is detected in a trajectory from traversal of the designated structure location, to indicate changing physical dimensions of the prespecified feature. The fabrication process environment is then controlled in response to the physical species detection to fabricate the structural feature.

Abstract: This invention relates to a multi-layer lithographically fabricated device used to produce improved thin-film recording heads. It further relates to a focused particle beam system for milling a recording head pole-tip assembly without irradiating a sensitive structure, e.g. a read head, of the recording head. The invention precisely forms a pole-tip assembly by milling a second structural element without irradiating a first structural element. The invention avoids irradiating the first structural element by placing a first marker element, which can be imaged and/or damaged, in the same layer of a multi-layer lithographically fabricated device as the first structural element. The marker element has a fixed spatial relationship to the first structural element.

Abstract: A method is provided for grading the surface topography of a surface to improve step coverage for an overcoat. In accordance with one aspect of the present invention, an ABS of a slider and sensitive element of a magnetic head is graded to provide better step coverage of an overcoat of ultra-thin DLC film. After lapping the ABS, a thin film is deposited on the lapped surface to cover any scratches, irregularities, and steps. The thin film is sputter etched at a glancing angle to grade the topography of the slider ABS. Sputtering at a glancing angle removes the thin film in planar regions faster than the thin film under the shadow of the glancing angle, which is near surface irregularities. The graded surface is then covered by a DLC deposition.

Abstract: A method and system for tuning a bulk acoustic wave device at the wafer level by adjusting the device thickness. In particular, the device thickness has a non-uniformity profile across the device surface. A mask with an aperture is placed over the device surface and a particle beam is applied over the mask to allow part of the particle beam to make contact with the device surface at a localized area beneath the aperture. The particles that pass through the aperture are deposited on the device surface to add material on the device surface, thereby increasing the surface thickness to correct for thickness non-uniformity. Alternatively, the particles that pass through the aperture remove part of the device surface in an etching process, thereby reducing the surface thickness. Prior to thickness adjustment, a frequency measurement device or thickness measurement device is used to map the device surface for obtaining the non-uniformity profile.

Abstract: A method for fabricating a resonator, and in particular, a thin film bulk acoustic resonator (FBAR), and a resonator embodying the method are disclosed. An FBAR is fabricated on a substrate by reducing mass from a top electrode layer. For a substrate having multiple resonators, mass is reduced from only selected resonator to provide resonators having different resonance frequencies on the same substrate.

Abstract: An improved method and apparatus for applying discrete area holograms or other optical devices directly onto documents or other substrates in a continuous process analogous to the operation of a printing press. The continuous process is carried out in a vacuum chamber in which at least two process steps are performed in sequence: the formation of a micro-grooved discrete resin area and a localized coating of it with a reflective or refractive material layer. The formation of the micro-grooved resin area can be accomplished by electron beam curing of the resin. The localized coating of the micro-grooved resin can be done by sputtering. One or more other steps, including pre-coating, post-coating and partial removal of the reflective or refractive layer, may also be carried out as part of the continuous process within the vacuum chamber.