Abstract: Methods described include placing a sensor system over a substrate positioned on a chuck. The sensor system generates a beam of optical energy towards the substrate and is configured to receive optical energy deflected from the substrate. The sensor system generates sensor signals in response to variations in received optical energy from the substrate and the chuck.

Abstract: An apparatus and method for controlling the curing process during the manufacture of composite laminates and components. The apparatus including a temperature controlled vessel such as an autoclave in which the material is placed during curing and an infra-red temperature measuring device such as a camera located remotely from the component to measure the temperature of at least part of the material during curing.

Abstract: A method for manufacturing an optical disc master using an existing exposure system, and a method for manufacturing an optical disc having higher recording capacity. The method for manufacturing an optical disc, using a master to produce the optical disc having an irregular pattern thereon, the master being produced by the steps of forming a resist layer composed of a resist material including an incomplete oxide of a transition metal such as W or Mo on a substrate, the oxygen content of the incomplete oxide being smaller than the oxygen content of the stoichiometric composition corresponding to a valence of the transition metal; selectively exposing the resist layer with laser according to a recording signal pattern using a light source with an irradiation power that is less than an irradiation threshold power at which exposure of the resist starts; and developing the resist layer to form the predetermined irregular pattern.

Abstract: The present invention provides a method of measuring the placement of material forming a blow-molded plastic container after the container is released from a mold of a blow molder having a plurality of molds, wherein each plastic container comprises a continuous sidewall and a base, the method comprising the steps of: detecting with an infrared camera infrared light emitted from the container after the container is released from a mold; converting the detected infrared light into corresponding electrical signals; transmitting the electrical signals to a microprocessor; comparing in the microprocessor the electrical signals with stored data regarding desired material distribution forming the plastic container; and producing output information regarding the placement of material forming the container.

Abstract: An imprint apparatus includes a detector and an adjusting device. A second mark formed on a substrate includes a grating pattern having grating pitches in first and second directions which are respectively parallel to first and second axes which are parallel to a pattern surface of a mold and orthogonal to each other. A first mark formed on the mold includes a grating pattern having a grating pitch in the first direction. The first and second marks have different grating pitches in the first direction. The detector includes an image sensor, and an optical system which forms a moire fringe on an image sensing surface of the image sensor. The adjusting device adjusts, in a plane including the second axis and a third axis that is perpendicular to the first and second axes, an angle between the optical axis of the detector and the third axis.

Abstract: A device for analyzing defects, particularly for items made of plastics, such as battery casings and the like, comprising at least one probe, which is adapted to be moved closer to, or to come into contact with, the item made of plastics to be tested, the probe being provided with a plurality of elements to which a high voltage is applied.

Abstract: A method for quality surveillance in manufacturing tablets in a rotary tablet press which, in a compression chamber, has a rotor with upper and lower rams, a die-plate, a cam system for the rams, at least one compressing station, and a charging system for the powdered material requiring compression wherein the tablets are checked for chemical and/or mechanical properties, wherein at least some chemical and/or mechanical data of the tablets is obtained by means of a NIR or LIF sensor in the compression chamber after the upper rams have left the dies, after a measuring procedure has been initiated by a machine computer in response to the die positions determined by a position generator relative to the NIR or LIF sensor.

Abstract: An imprint lithography template is provided with an alignment mark, wherein the alignment mark is formed from dielectric material having a refractive index which differs from the refractive index of the imprint lithography template, the dielectric material having a thickness which is such that it provides a phase difference between alignment radiation which has passed through the dielectric material and alignment radiation which has not passed through the dielectric material.

Abstract: Acceptance/rejection of a deposition condition is judged by detecting an exothermic quantity of a deposition portion 3 by using an infrared beam sensor 2 during laser deposition of a resin material 4 having transmissibility to a laser beam and a resin material 5 having absorptivity to the laser beam L. The exothermic condition of the deposition portion is detected by using an infrared beam sensor matching with a wavelength of an infrared beam having a high transmission factor from infrared beam transmission characteristics of the transmissible resin to judge whether or not suitable energy is applied to the deposition portion and whether or not the deposition portion is formed. The exothermic quantity of the transmissible resin is detected by an infrared beam sensor 2A to judge acceptance or rejection of the deposition portion even when the applied energy changes.

Abstract: A pattern transfer apparatus transfers an imprint pattern formed on a mold, provided with an alignment mark, to a resin material on a substrate, provided with an alignment mark. A first image pickup device obtains an image of an object positioned at a first object position. A second image pickup device obtains an image of an object positioned at a second object position. The second object position is more distant from the alignment mark of the mold than the first object position. An optical system forms an image of an object positioned at the first object position and an image of an object positioned at the second object position. Alignment is performed based on first and second information obtained about positions of images of an alignment mark of a reference substrate and an alignment mark of the substrate, to transfer the imprinting pattern to the resin material.

Abstract: According to one embodiment, first image information of a mold is acquired by irradiating the mold with first light, the mold having an uneven pattern with a shape corresponding to a pattern to be transferred onto a substrate to be processed. The position of the uneven pattern of the mold is adjusted by applying stress to the mold. Second image information is acquired by irradiating the mold whose position is adjusted with the first light. Stress information of the mold whose position is adjusted is measured by comparing the first image information with the second image information. The position adjustment is repeated until the measurement result satisfies a desired condition, and a pattern is formed on the substrate by using the mold whose position is adjusted.

Abstract: A transparent imprint template mold is configured with gratings surrounding the active imprint area. The gratings are fabricated at the same time as the active area and thus accurately define the active area with respect to the gratings. The substrate is positioned in tool coordinates under the template mold. A sensor system generates a beam of optical energy and receives reflected energy only at a specific angular window and is used to locate the template mold. The sensor system is scanned to locate the substrate and the gratings in tool coordinates. In this manner, the relative position of the template mold is determined with respect to the substrate in tool coordinates. The substrate is then accurately positioned with respect to the template mold. The system may be used to track imprinted pattern position relative to the substrate and to determine concentricity of patterns to substrates.

Abstract: A processing method for transferring a relief pattern of a mold to a resist includes the steps of compressing the mold having the relief pattern against the resist on a substrate, irradiating an exposure light onto the resist through the mold, vibrating the mold and the substrate relative to each other during the irradiating step, and releasing the mold from the resist.

Abstract: An imprinting machine that brings a mold having a pattern into contact with an object and transfers the pattern onto the object includes a measurement unit that measures a position of the mold when the mold contacts the object.

Abstract: The invention relates to systems and methods which may be used to determine when an uncured composite part is ready to be cured. In one embodiment, a system under the invention may comprise an infrared camera adapted to take infrared images of an uncured composite part, a heating device adapted to heat an uncured composite part, an image capture device adapted to capture infrared images taken by the infrared camera, and a computer adapted to analyze infrared images taken by the infrared camera in order to evaluate temperatures of an uncured composite part. The infrared images may be used to determine that the composite part is substantially covered, and/or completely covered, with resin and ready to be cured.

Abstract: A method of controlling power applied to an induction coil assembly used for densifying porous articles with a liquid matrix precursor. The control of applied power addresses dynamic changes in the electrical characteristics of the porous article being densified as it becomes denser. In particular, the power applied is controlled in accordance with changes in resonant frequency of the coupled system of the induction heating system and the porous article.

Abstract: The present invention relates to a capacitive measurement method and system for a nanoimprint process, which arranges a plurality of electrode plates on both the backside of the master mold and the surface of the supporting base carrying the wafer substrate to form a plurality of capacitive structures. By monitoring the capacitance variation signal caused by the continuous variations in the thickness and the material properties of the resist during the imprint process, the status of the resist can be monitored and recorded, which is used as the references for determining the timing to demold in the nanoimprint process and for maintaining the flatness of the resist. Accordingly, the nanoimprint process can be automated easier and the quality and the throughput of of the nanometer scaled imprint product can be improved.

Abstract: Process and apparatus for non-invasive measuring of binder mix loading of glass fibers for monitoring production of construction insulation product, such as roofing and wall insulation. The process utilizes visible (VIS) and near infrared (NIR) spectroscopy; and, is particularly advantageous when utilized in an on-line production processing following binder mix loading of glass fibers and prior to curing treatment of the binder mix loaded glass fibers. Such spectroscopic analyses can be carried out on a static or moving support substrate. The blend is then conveyed to and through curing treatment to form insulation product. The blend is exposed to VIS-NIR radiant energy, and a radiant energy sensor collects resulting data as to absorption following penetration of the VIS-NIR radiant energy. The spectroscopic instrumentation is calibrated to determine to facilitate accuracy; and, can be used to verify load following curing.

Abstract: A jig for holding a core which comprises a movable platform, a base positioned on the movable platform which has a receiving hole, and an inserter positioned inside the receiving hole of the base, shaped corresponding to the shape of the receiving hole, to fasten the core to the inserter. The inserter comprises a core receiving hole, a plurality of positioning recesses disposed symmetrically in the periphery of the core receiving hole, a plurality of positioning blocks received in the positioning recesses, and a plurality of resilient elements received in a space between the positioning recesses and the positioning blocks to hold the core firmly.

Abstract: A method for light-curing polymerizable materials to form a dental device is provided. A light-curing apparatus having at least one integrated lighting and heating source, a curing volume, and a temperature controller, preferably a fan, is used in the method. The light source and temperature controller are used to heat a first polymerizable material to temperatures within a first temperature range. A second polymerizable material is applied on or adjacent to the first polymerizable material. The light source and temperature controller are used to heat the second polymerizable material to temperatures within a second temperature range. The first temperature range has a first midpoint and the second temperature range has a second midpoint. The first midpoint temperature is at least 10° C. apart from the second midpoint temperature.

Abstract: Through hole (3) for product, through holes (7a, 7b) for laminate recognition marks, through holes (8a, 8b) for an X-ray recognition marks are formed on prepreg sheet (1) having mold release films (2a, 2b) attached to the front and back surfaces thereof. By masking through holes (7a, 7b) for laminate recognition mark, conductive paste (4) is filled in through hole (3) for product and through holes (8a, 8b) for X-ray recognition marks. Thereafter, mold release films (2a, 2b) are removed so as to manufacture a circuit board. Since conductive paste (4) is not filled in through holes (7a, 7b) for laminate recognition marks, a recognition mark with high laminating accuracy can be easily obtained, and a high density and high quality circuit formation substrate having improved laminating accuracy can be obtained.

Abstract: The cross-sectional shape data of a three-dimensional model is divided according to work small areas obtained by dividing a work entire area where optical shaping work is performed into a plurality of areas, and work small area data which is cross-sectional shape data corresponding to said work small areas is generated. Also, the work small area data is enlarged with offset width based on the contracting ratio of a light hardening resin, and areas, which are wider than the work small areas on the surface of the light hardening resin by the offset width, are subjected to one-shot exposure based on the enlarged work small area data to form a hardening layer for each of the work small areas. The present invention can be applied to, for example, an optical shaping apparatus.

Abstract: An electrospinning system using a spinneret and a counter electrode is first operated for a fixed amount of time at known system and operational parameters to generate a fiber mat having a measured fiber mat width associated therewith. Next, acceleration of the fiberizable material at the spinneret is modeled to determine values of mass, drag, and surface tension associated with the fiberizable material at the spinneret output. The model is then applied in an inversion process to generate predicted values of an electric charge at the spinneret output and an electric field between the spinneret and electrode required to fabricate a selected fiber mat design. The electric charge and electric field are indicative of design values for system and operational parameters needed to fabricate the selected fiber mat design.

Abstract: Calibrating visual (VIS) and near infra red (NIR) spectroscopic instrumentation for quantitative measurement of resin-loading of prepared wood materials, as moving in an assembly-forming line, for subsequent pressing under heat and pressure for manufacture of engineered-composite wood product. Feedback of measured data of resin-loading, during in-line assembly operations, enables maintaining consistent resin-loading and optimizes resin usage. Calibration of VIS/NIR spectroscopic instrumentation can be carried out on equipment simulating in-line movement of pre-established reference-source test-samples; or, can be carried out during on-line movement of wood-material test samples. The developed calibration method removes absorptive effects at wavelengths for constituents other than resin, such as the moisture content of the wood-materials and of the resin, while maintaining accurate and prompt VIS/NIR spectroscopic measurements of resin-loading in a continuous assembly line.

Abstract: A nano-molding process including an imprint process that replicates features sizes less than 7 nanometers. The nano-molding process produces a line edge roughness of the replicated features that is less than 2 nanometers. The nano-molding process including the steps of: a) forming a first substrate having nano-scale features formed thereon, b) casting at least one polymer against the substrate, c) curing the at least one polymer forming a mold, d) removing the mold from the first substrate, e) providing a second substrate having a molding material applied thereon, f) pressing the mold against the second substrate allowing the molding material to conform to a shape of the mold, g) curing the molding material, and h) removing the mold from the second substrate having the cured molding material revealing a replica of the first substrate.

Abstract: A method of manufacturing an article may include crosslinking a UHMWPE preform, shaping the crosslinked preform, heat-treating the shape in a temperature-controlled oven and low-oxygen environment, and inspecting the heat-treated shape for conformance to article specifications.

Abstract: The present technique provides for the use of spectroscopic probes, such as Raman probes, within the conduits of a polyolefin production system. The Raman probe or other spectroscopic probes may be used to obtain spectroscopic measurements of the contents of the conduits. The spectroscopic measurements may be processed and analyzed to determine the composition of the conduit contents. In addition, the spectroscopic measurements may be used in conjunction with correlations or other statistical models to determine one or more properties of interest of a constituent of the conduit contents. One or more processes upstream and/or downstream of the conduit may be adjusted in response to the determined composition or composition properties.

Abstract: The method of making a high quality fluoride crystalline optical microlithography lens element blank includes crystallizing a fluoride crystalline member with dimension ?200 mm from a melt, annealing the fluoride crystalline member and qualifying the resulting member for use as an optical microlithography lens element blank The fluoride crystalline optical lithography lens element blanks have multiple adjoining abutting crystalline subgrains with low boundary angles. The crystalline members made by the method are qualified for use as lens element blanks by a testing method including measuring their absorption spectra at 200 to 220 nm to determine absorbance at 205 nm and/or by making measurements of radiation diffracted by them.

Abstract: An apparatus for formation of a three dimensional object comprising a sealed container; an electron beam subsystem capable of directing energy within said container; a positioning subsystem contained within said container; a wire feed subsystem contained within said container; an instrumentation subsystem electronically connected to said electron beam subsystem, positioning subsystem, and wire feed subsystem; and a power distribution subsystem electrically connected to said electron beam subsystem, positioning subsystem, wire feed subsystem, and said instrumentation subsystem.

Abstract: Method for spectroscopically monitoring resin applied to a planar surface of veneer-wood sheets during travel in an assembly line. Spectroscopic instrumentation for monitoring applied resin is calibrated by measurements of predetermined resin applications to reference-test-samples, so as to provide a pre-determined relationship enabling monitoring of applied resin, during commercial production of a veneer-wood product using the visible light spectrum and near infrared extending to 2500 nm. Monitoring of selected radiation absorbance by the applied resin is carried out by spectroscopic measurement of non-absorbed electromagnetic radiation, as reflected back by the wood-veneer matrix; selected wavelengths are utilized for determining average resin-weight per designated surface area of a sheet.

Abstract: Process for calibration of spectroscopic instrumentation for non-invasive monitoring of resin-loading of furnish-type wood materials, such as particles or fibers for particleboard or medium density fiberboard, respectively. Selection of ranges of wavelengths within a 350 nm to 2500 nm region by providing selection of spectrometers and sensors for wavelength ranges of 350–1000 nm, 1000 to 1800 nm, 1000 to 2500 nm, and 400 to 2200 nm, for use by engineered-wood manufacturing installations. Resin-loaded wood material is exposed to selected VIS/NIR energy and monitored as it moves on-line in relation to calibrated spectroscopic instrumentation; a sensor collects non-absorbed radiation energy reflected by the wood materials. Measurements are processed, in relation to pre-established calibration data, to determine whether the resin-loading is within manufacturing objectives; monitoring and feedback are used to maintain desired specifications.

Abstract: An illustrative object of the present invention is to provide a microprocessing apparatus by which an original and a substrate to be processed can be aligned with each other with a higher precision. Disclosed in this connection is an apparatus for transferring a pattern of an original onto a substrate while maintaining the original and the substrate in contact with each other or in close proximity to each other, wherein the apparatus includes an original holding device for holding the original, a substrate holding device for holding the substrate, a reference mark, and a position measuring system for measuring a relative positional relationship between the reference mark and a mark formed on at least one of the original and the substrate.

Abstract: Method for spectroscopically monitoring resin applied to a planar surface of veneer-wood sheets during travel in an assembly line. Spectroscopic instrumentation for monitoring applied resin is calibrated by measurements of predetermined resin applications to reference-test-samples, so as to provide a pre-determined relationship enabling monitoring of applied resin, during commercial production of a veneer-wood product using the visible light spectrum and near infrared extending to 2500 nm. Monitoring of selected radiation absorbance by the applied resin is carried out by spectroscopic measurement of non-absorbed electromagnetic radiation, as reflected back by the wood-veneer matrix; selected wavelengths are utilized for determining average resin-weight per designated surface area of a sheet.

Abstract: A method of manufacturing a honeycomb structure and a through hole forming device used in the manufacture of the honeycomb structure are provided, in which the step of closing a part of the cell ends at an end surface of the honeycomb structure is rationalized. In closing a part of the cell ends (82) at the end surface (861) of a honeycomb structure body (86), a film (2) is attached to the end surface (861) of the honeycomb structure body (86) in such a manner as to cover the cell ends (82). The portion of the film (2) located at the cell ends (82) to be closed is thermally melted or burnt off thereby to form through holes (20). The end surface (861) is dipped in a slurry containing an end surface closing material, so that the slurry is caused to enter the cell ends (82) by way of the through holes (20). After that, the slurry is hardened while at the same time removing the resin film (2).

Abstract: Process for calibration of spectroscopic instrumentation for non-invasive monitoring of resin-loading of furnish-type wood materials, such as particles or fibers for particleboard or medium density fiberboard, respectively. Selection of ranges of wavelengths within a 350 nm to 2500 nm region by providing selection of spectrometers and sensors for wavelength ranges of 350-1000 nm, 1000 to 1800 nm, 1000 to 2500 nm, and 400 to 2200 nm, for use by engineered-wood manufacturing installations. Resin-loaded wood material is exposed to selected VIS/NIR energy and monitored as it moves on-line in relation to calibrated spectroscopic instrumentation; a sensor collects non-absorbed radiation energy reflected by the wood materials. Measurements are processed, in relation to pre-established calibration data, to determine whether the resin-loading is within manufacturing objectives; monitoring and feedback are used to maintain desired specifications.

Abstract: Calibrating near infra red (NIR) spectroscopic instrumentation for quantitative measurement of resin-loading of prepared wood materials, as moving in an assembly-forming line, for subsequent pressing under heat and pressure for manufacture of engineered-composite wood product. Feedback of measured data of resin-loading, during in-line assembly operations, enables maintaining consistent resin-loading and optimizes resin usage. Calibration of NIR spectroscopic instrumentation can be carried out on equipment simulating in-line movement of pre-established reference-source test-samples; or, can be carried out during on-line movement of wood-material test samples. The developed calibration method removes absorptive effects at wavelengths for constituents other than resin, such as the moisture content of the wood-materials and of the resin, while maintaining accurate and prompt NIR spectroscopic measurements of resin-loading in a continuous assembly line.

Abstract: A semiconductor chip molding apparatus includes an upper platen including an upper mold, a lower platen including a lower mold having a molding block configured to receive a lead frame, a controller, and an electrical detector for forming an electrical circuit between the controller and the lead frame when the lead frame is oriented improperly on the lower mold. A low-level test voltage is imparted to at least the lower mold. As a result, an electrical signal will flow from the detecting block when the lead frame rests on the detecting block. When such a signal is detected, therefore, the lead frame is determined as having been improperly set on the molding block. The signal generated is detected by a controller and used thereby to interrupt the operation of the molding apparatus.

Abstract: A method of determining and correcting alignment during imprint lithography process is described. During an imprint lithographic process the template may be aligned with the substrate by the use of alignment marks disposed on both the template and substrate. The alignment may be determined and corrected for before the layer is processed.

Abstract: Method of making a high quality identifiable fluoride crystalline optical microlithography lens element blank for formation into an lens element of a microlithography system. The highly qualified fluoride crystalline characteristics of the fluoride optical lithography lens blank ensure its beneficial performance in the demanding microlithography manufacturing regime which utilizes high energy short wavelength ultraviolet laser sources. The fluoride crystalline optical lithography lens element blanks are comprised of multiple adjoining abutting crystalline subgrains with low boundary angles.

Abstract: Described are methods for patterning a substrate by imprint lithography. Imprint lithography is a process in which a liquid is dispensed onto a substrate. A template is brought into contact with the liquid and the liquid is cured. The cured liquid includes an imprint of any patterns formed in the template. Alignment of the template with the substrate is performed prior to curing the liquid. Alignment of the template with the substrate includes rotational alignment of the template with respect to the substrate.

Abstract: A cross-section is obtained in which a sample shape is clearly delineated by forming a covering layer of a material different from that of the sample surface on the sample surface, forming a protective layer on the covering layer forming a hole in the protective and covering layers and the sample surface to expose the cross-section, and tilting the sample and scanning the cross-section with a focused ion beam so as to obtain a microscopic image of the cross-section. By forming the covering layer of a material different from that of the sample surface, the shape of the sample can be clearly viewed in the obtained image.

Abstract: A method for plugging selected cell channels in a honeycomb structure for the fabrication of a solid particulate filter. The method includes covering a first end face of the honeycomb structure with a mask having openings corresponding to open ends of a first plurality of cell channels; loading powdered plugging material from through the mask openings into the first plurality of cell channels; forming plugs in the first plurality of cell channels at ends opposite the first end face of the honeycomb structure; loading powdered plugging material into the open ends of a second plurality of cell channels open at the second end face of the honeycomb structure; and forming plugs in the second plurality of cell channels at the ends adjacent the first end face of the honeycomb structure.

Abstract: The invention is a process for radiant curing of a coating on a three-dimensional object.

Abstract: A rapid throughput method for the preparation, analysis or both of libraries of material samples is provided. According to the method, a plurality of samples is provided. Providing the plurality of samples can include a variety of sample formation techniques including, but not limited to, extruding, milling, compression preparation, rotary mixing, microcentrifugation, molding and casting. Preferably, the samples are solidified into a near net shape configuration appropriate for testing of properties or characteristics of the samples.

Abstract: The present invention relates to a method of forming a tissue implant that includes applying force to the tissue to form the implant which has a predetermined shape. The applied force against the tissue is monitored or controlled during the shaping of the tissue.

Abstract: A method for fabricating periodically poled structures. The method produces an electric field within a ferroelectric substrate by applying a voltage waveform to an electrode structure disposed on a surface of the substrate. The waveform raises the electric field magnitude to a level substantially greater than that required to reverse domains within the substrate. The waveform then lowers the voltage such that the electric field has a value at which a domain wall velocity is most sensitive to changes in the field. The waveform maintains the electric field value until a current through the substrate drops substantially. The electric field is then lowered to a value below a level required to sustain domain wall motion, but greater than a level below which backswitching occurs. The electric field is then lowered to zero in such a way as to prevent backswitching.

Abstract: A ceramic article is fired using a combination of microwave energy and conventional heating energy according to a microwave power-time heating schedule comprising a series of separate firing segments at predetermined microwave power settings, the core and surface temperatures of the article being monitored during firing to determine the core-surface temperature differential, that differential being controlled and limited to prevent cracking of the ceramic article by adjusting the level of applied conventional heat energy during firing.

Abstract: A method of manipulating data in a method for forming a three-dimensional object layer by layer from an ink jettable, solidifiable material by providing data corresponding to a plurality of polygons defining the outer surfaces of a plurality of three-demiensional objects and providing sets of x, y, and z coordinates corresponding to each layer and identifying x and y coordinates with each z coordinate such that directional values and counter values are determined for each y coordinate in a first set of coordinates generated. A second set of y coordinates are generated according to a formula that permits the determined layers to be processed to form a three-dimensional object.

Abstract: A method for producing a fired decoration with an essentially defect-free visual appearance on substrates made of glass, glass-ceramic, ceramic, or other substances with other decorative colors consisting of base enamel, pigments, and additives, whereby as additives, UV-sensitive optical whitening agents, in particular thiophene-benzoxazol derivatives, are added to the decorative color.

Abstract: A method of measuring the width of bottom under cut includes forming spacers around an oxide line pattern and determining the width of the tail ends of the spacers that are removed along with the bottom under cut. An oxide line pattern is first formed on a substrate and a deposition layer is then deposited thereon. The deposition layer is etched to form a deposition pattern by using a photoresist pattern as a mask. A spacer is also formed against each side wall of the oxide line pattern as a result of the etching process. The etching is continued to under cut the deposition pattern and remove the tail ends of the spacers. By measuring the width of the photoresist pattern, the width of the spacer before and after the tail end is removed during each respective step, the width of the bottom under cut can be determined.