Abstract: A method for designing a two-dimensional array overlay target set comprises the steps of: selecting a plurality of two-dimensional array overlay target sets having different overlay errors; calculating a deviation of a simulated diffraction spectra for each two-dimensional array overlay target set; selecting a sensitive overlay target set by taking the deviations of the simulated diffraction spectra into consideration; and designing a two-dimensional array overlay target set based on the structural parameters of the sensitive overlay target set.

Abstract: A system for through silicon via (TSV) structure measurement comprises a reflectometer, and a computing unit. The reflectometer emits a broadband light beam to at least a TSV structure and receives a reflection spectrum of at least a TSV structure. The computing unit is coupled with the reflectometer and determines the depth of the TSV structure in accordance with the reflection spectrum.

Abstract: A method for measuring a via bottom profile is disclosed for obtaining a profile of a bottom of a via in a front side of a substrate. In this method, an infrared (IR) light source is transmitted from the back of the substrate to the bottom of the via through an objective by using an IR-microscope, and lights scattered from the bottom of the via are acquired by an image capturing device to generate an image, where the image displays a diameter (2Ea) of the via bottom profile and a diameter (2Ec) of a maximum receivable base area of the via for the IR-microscope. Thereafter, by using an elliptic equation, a minor axis radius thereof (Eb) is obtained, and thus the via bottom profile is obtained from a radius (Ea) of the via bottom profile and the minor axis radius (Eb) of the elliptic equation.

Abstract: A system for via structure measurement is disclosed. The system comprises a reflectometer, a simulation unit and a comparing unit. The reflectometer is configured to collect a measured diffraction spectrum of at least a via. The simulation unit is configured to provide simulated diffraction spectrums of the at least a via. The comparing unit is configured to determine at least a depth and at least a bottom profile of the at least a via by comparing the collected diffraction spectrum and the simulated diffraction spectrums.

Abstract: A method for designing an overlay target comprises selecting a plurality of overlay target pairs having different overlay errors or offsets, calculating a deviation of the simulated diffraction spectrum for each overlay target pair, selecting a plurality of sensitive overlay target pairs by taking the deviation of the simulated diffraction spectrum into consideration, selecting an objective overlay target pair from the sensitive overlay target pairs by taking the influence of the structural parameters to the simulated diffraction spectrum into consideration, and designing the overlay target pair based on the structural parameter of the objective overlay target pair.

Abstract: A system for via structure measurement is disclosed. The system comprises a reflectometer, a simulation unit and a comparing unit. The reflectometer is configured to collect a measured diffraction spectrum of at least a via. The simulation unit is configured to provide simulated diffraction spectrums of the at least a via. The comparing unit is configured to determine at least a depth and at least a bottom profile of the at least a via by comparing the collected diffraction spectrum and the simulated diffraction spectrums.

Abstract: A method for designing a two-dimensional array overlay target set comprises the steps of: selecting a plurality of two-dimensional array overlay target sets having different overlay errors; calculating a deviation of a simulated diffraction spectra for each two-dimensional array overlay target set; selecting a sensitive overlay target set by taking the deviations of the simulated diffraction spectra into consideration; and designing a two-dimensional array overlay target set based on the structural parameters of the sensitive overlay target set.

Abstract: A method for designing a two-dimensional array overlay target comprises the steps of: selecting a plurality of two dimensional array overlay targets having different overlay errors; calculating a deviation of a simulated diffraction spectrum for each two-dimensional array overlay target; selecting an error-independent overlay target by taking the deviations of the simulated diffraction spectra into consideration; and designing a two dimensional array overlay target based on structural parameters of the error-independent overlay target.

Abstract: A method and an apparatus are disclosed for scatterfield microscopical measurement. The method integrates a scatterometer and a bright-field microscope for enabling the measurement precision to be better than the optical diffraction limit. With the aforesaid method and apparatus, a detection beam is generated by performing a process on a uniform light using an LCoS (liquid crystal on silicon) or a DMD (digital micro-mirror device) which is to directed to image on the back focal plane of an object to be measured, and then scattered beams resulting from the detection beam on the object's surface are focused on a plane to form an optical signal which is to be detected by an array-type detection device. The detection beam can be oriented by the modulation device to illuminate on the object at a number of different angles, by which zero order or higher order diffraction intensities at different positions of the plane at different incident angles can be collected.

Abstract: A reflective scatterometer capable of measuring a sample is provided. The reflective scatterometer includes a paraboloid mirror, a light source, a first reflector, a second reflector and a detector. The paraboloid mirror has an optical axis and a parabolic surface, wherein the sample is disposed on the focal point of the parabolic surface and the normal direction of the sample is parallel with the optical axis. A collimated beam generated from the light source is reflected by the first reflector to the parabolic surface and then is reflected by the parabolic surface to the sample to form a first diffracted beam. The first diffracted beam is reflected by the parabolic surface to the second reflector and is then reflected by the second reflector to the detector.

Abstract: In an overlay metrology method used during semiconductor device fabrication, an overlay alignment mark facilitates alignment and/or measurement of alignment error of two layers on a semiconductor wafer structure, or different exposures on the same layer. A target is small enough to be positioned within the active area of a semiconductor device combined with appropriate measurement methods, which result in improved measurement accuracy.

Abstract: A method for designing a grating comprises steps of (a1) generating a first diffraction spectrum based on calculation values of a plurality of structural parameters, (a2) calculating a first difference value between the first diffraction spectrum and a first nominal spectrum, (a3) setting a default difference value with the first difference value and default structural parameter values with the structural parameter values, (b1) changing one of the structural parameter values to generate a second diffraction spectrum, (b2) calculating a second difference value between the second diffraction spectrum and a second nominal spectrum, and (c) comparing the default difference value and the second difference value, updating a default difference value with the smaller one, and updating the default structural parameter values with the structural parameter values corresponding to the smaller one.

Abstract: A reflective scatterometer capable of measuring a sample is provided. The reflective scatterometer includes a paraboloid mirror, a light source, a first reflector, a second reflector and a detector. The paraboloid mirror has an optical axis and a parabolic surface, wherein the sample is disposed on the focal point of the parabolic surface and the normal direction of the sample is parallel with the optical axis. A collimated beam generated from the light source is reflected by the first reflector to the parabolic surface and then is reflected by the parabolic surface to the sample to form a first diffracted beam. The first diffracted beam is reflected by the parabolic surface to the second reflector and is then reflected by the second reflector to the detector.

Abstract: A structure for overlay measurement is provided in the present invention, using the diffraction characteristics on the boundary portion between two microstructures formed on each of two material layers. The optical intensity distribution on the boundary portion between microstructures formed on the two overlaid material layers respectively are measured by an optical microscope to obtain the overlay error between the two overlaid material layers. In addition, the present invention also provides a method for overlay measurement using the structure for overlay measurement, wherein a merit relation based on the optical intensity distribution on the boundary portion between different microstructures is determined. The merit relation can be used to analyze the overlay error to improve the efficiency and accuracy of on-line error measurement.

Abstract: The present invention provides a scatterfield microscopical measuring method and apparatus, which combine scatterfield detecting technology into microscopical device so that the microscopical device is capable of measuring the sample whose dimension is under the limit of optical diffraction. The scatterfield microscopical measuring apparatus is capable of being controlled to focus uniform and collimated light beam on back focal plane of an objective lens disposed above the sample. By changing the position of the focus position on the back focal plane, it is capable of being adjusted to change the incident angle with respect to the sample.

Abstract: A method for designing an overlay target comprises selecting a plurality of overlay target pairs having different overlay errors or offsets, calculating a deviation of the simulated diffraction spectrum for each overlay target pair, selecting a plurality of sensitive overlay target pairs by taking the deviation of the simulated diffraction spectrum into consideration, selecting an objective overlay target pair from the sensitive overlay target pairs by taking the influence of the structural parameters to the simulated diffraction spectrum into consideration, and designing the overlay target pair based on the structural parameter of the objective overlay target pair.

Abstract: A method of measuring dimensions for an optical system to measure the critical dimension of a sample object according to this aspect of the present invention includes the steps of preparing a plurality of standard objects, selecting a predetermined focus metric algorithm, performing an analyzing process on each standard object to generate a plurality of focus metric distributions using the predetermined focus metric algorithm, analyzing the focus metric distributions to determine a target order, generating a reference relation, acquiring a measured characteristic value from the sample object, and determining the critical dimension of the sample object based on the measured characteristic value and the reference relation. Each standard object has a grating-shaped standard pattern with a predetermined pitch and line width. The focus metric algorithm is a gradient energy method, a Laplacian method, a standard deviation method, or a contrast method.

Abstract: A system and method for efficiently and accurately determining grating profiles uses characteristic signature matching in a discrepancy enhanced library generation process. Using light scattering theory, a series of scattering signatures vs. scattering angles or wavelengths are generated based on the designed grating parameters, for example. CD, thickness and Line:Space ratio. This method selects characteristic portions of the signatures wherever their discrepancy exceeds the preset criteria and reforms a characteristic signature library for quick and accurate matching. A rigorous coupled wave theory can be used to generate a diffraction library including a plurality of simulated diffraction spectrums based on a predetermined structural parameter of the grating. The characteristic region of the plurality of simulated diffraction spectrums is determined based on if the root mean square error of the plurality of simulated diffraction spectrums is larger than a noise level of a measuring machine.

Abstract: A structure for overlay measurement is provided in the present invention, using the diffraction characteristics on the boundary portion between two microstructures formed on each of two material layers. The optical intensity distribution on the boundary portion between microstructures formed on the two overlaid material layers respectively are measured by an optical microscope to obtain the overlay error between the two overlaid material layers. In addition, the present invention also provides a method for overlay measurement using the structure for overlay measurement, wherein a merit relation based on the optical intensity distribution on the boundary portion between different microstructures is determined. The merit relation can be used to analyze the overlay error to improve the efficiency and accuracy of on-line error measurement.

Abstract: A method and an apparatus are disclosed for scatterfield microscopical measurement. The method integrates a scatterometer and a bright-field microscope for enabling the measurement precision to be better than the optical diffraction limit. With the aforesaid method and apparatus, a detection beam is generated by performing a process on a uniform light using an LCoS (liquid crystal on silicon) or a DMD (digital micro-mirror device) which is to directed to image on the back focal plane of an object to be measured, and then scattered beams resulting from the detection beam on the object's surface are focused on a plane to form an optical signal which is to be detected by an array-type detection device. The detection beam can be oriented by the modulation device to illuminate on the object at a number of different angles, by which zero order or higher order diffraction intensities at different positions of the plane at different incident angles can be collected.