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 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 method for correlating a structural parameter of a plurality of gratings acquires images from a plurality of gratings, which have different structural parameters. A focus metrics algorithm is then performed to find the off-focus offset of the orders of each grating from the intensity variation of these images, and the variation ratio of the off-focus offset to the order for each grating is calculated later. Consequently, the structural parameters of these gratings can be correlated based on the variation ratio of the off-focus offset to the order. The present method acquires images from an unknown grating at different off-focus offsets, and performs a focus metrics algorithm to find the off-focus offset of the orders of the unknown grating. The variation ratio is calculated and the structural parameter of the unknown grating is determined based on the variation ratio.

Abstract: A method for inspecting a grating biochip comprises the steps of irradiating a grating biochip using a light beam, measuring a diffracted light using a photodetector, selecting a plurality of parameters of the grating biochip, and optimizing the parameters to enhance the detection sensitivity, wherein the diffracted light is generated by the light beam passing the grating biochip. The grating biochip comprises a grating structure including a semiconductor substrate, a grating positioned on the semiconductor substrate and a dielectric layer covering the grating and the semiconductor substrate. The sample of the biochip is positioned on the grating structure.

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: This disclosure provides methods for measuring asymmetry of features, such as lines of a diffraction grating. On implementation provides a method of measuring asymmetries in microelectronic devices by directing light at an array of microelectronic features of a microelectronic device. The light illuminates a portion of the array that encompasses the entire length and width of a plurality of the microelectronic features. Light scattered back from the array is detected. One or more characteristics of the back-scattered light may be examined by examining data from complementary angles of reflection. This can be particularly useful for arrays of small periodic structures for which standard modeling techniques would be impractically complex or take inordinate time.

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: Apparatuses and methods for analyzing semiconductor workpieces are disclosed herein. In one embodiment, for example, an apparatus for analyzing a semiconductor workpiece includes a first metrology unit configured to measure photoluminescence from the workpiece and a second metrology unit configured to determine a topographical profile of the workpiece. The apparatus can further include a control unit operatively coupled to the first metrology unit and the second metrology unit to receive and associate data regarding the photoluminescence and the topographical profile to produce an integrated map of the workpiece. The apparatus may have several different configurations. In one embodiment, for example, the first metrology unit and the second metrology unit can be housed in a single tool. In other embodiments, the first metrology unit and the second metrology unit may be in separate tools.

Abstract: A method for inspecting a grating biochip comprises the steps of irradiating a grating biochip using a light beam, measuring a diffracted light using a photodetector, selecting a plurality of parameters of the grating biochip, and optimizing the parameters to enhance the detection sensitivity, wherein the diffracted light is generated by the light beam passing the grating biochip. The grating biochip comprises a grating structure including a semiconductor substrate, a grating positioned on the semiconductor substrate and a dielectric layer covering the grating and the semiconductor substrate. The sample of the biochip is positioned on the grating structure.

Abstract: A target system for determining positioning error between lithographically produced integrated circuit fields on at least one lithographic level. The target system includes a first target pattern on a lithographic field containing an integrated circuit pattern, with the first target pattern comprising a plurality of sub-patterns symmetric about a first target pattern center and at a same first distance from the first target pattern center. The target system also includes a second target pattern on a different lithographic field, with the second target pattern comprising a plurality of sub-patterns symmetric about a second target pattern center and at a same second distance from the second target pattern center. The second target pattern center is intended to be at the same location as the first target pattern center. The centers of the first and second target patterns may be determined and compared to determine positioning error between the lithographic fields.

Abstract: Non-contact methods and apparatuses for detecting defects such as pile-ups in semiconductor wafers are disclosed herein. An embodiment of one such method includes irradiating a portion of a semiconductor workpiece, measuring photoluminescence from the irradiated portion of the semiconductor workpiece, and estimating a density of defects in the irradiated portion of the semiconductor workpiece based on the measured photoluminescence.

Abstract: Scatterometers and methods of using scatterometry to determine several parameters of periodic microstructures, pseudo-periodic structures, and other very small structures having features sizes as small as 100 nm or less. Several specific embodiments of the present invention are particularly useful in the semiconductor industry to determine the width, depth, line edge roughness, wall angle, film thickness, and many other parameters of the features formed in microprocessors, memory devices, and other semiconductor devices. The scatterometers and methods of the invention, however, are not limited to semiconductor applications and can be applied equally well in other applications.

Abstract: Scatterometers and methods of using scatterometry to determine several parameters of periodic microstructures, pseudo-periodic structures, and other very small structures having features sizes as small as 100 nm or less. Several specific embodiments of the present invention are particularly useful in the semiconductor industry to determine the width, depth, line edge roughness, wall angle, film thickness, and many other parameters of the features formed in microprocessors, memory devices, and other semiconductor devices. The scatterometers and methods of the invention, however, are not limited to semiconductor applications and can be applied equally well in other applications.

Abstract: Scatterometers and methods of using scatterometry to determine several parameters of periodic microstructures, pseudo-periodic structures, and other very small structures having features sizes as small as 100 nm or less. Several specific embodiments of the present Invention are particularly useful in the semiconductor industry to determine the width, depth, line edge roughness, wall angle, film thickness, and many other parameters of the features formed in microprocessors, memory devices, and other semiconductor devices. The scatterometers and methods of the invention, however, are not limited to semiconductor applications and can be applied equally well in other applications.

Abstract: Apparatuses and methods for evaluating microstructures on workpieces are disclosed herein. In one embodiment, a scatterometer comprises an irradiation source, an optic member, and an object lens assembly. The irradiation source can be a laser that produces a beam of radiation at a wavelength. The optic member is aligned with the path of the beam and configured to condition the beam (e.g., shape, randomize, select order, diffuse, converge, diverge, collimate, etc.), and the object lens assembly is positioned between the optic member and a workpiece site. The object lens assembly is configured to (a) simultaneously focus the conditioned beam through a plurality of altitude angles to a spot at an object focal plane, (b) receive radiation scattered from a workpiece, and (c) present a distribution of the scattered radiation at a second focal plane. The object lens assembly maintains a sine relationship between the altitude angles and corresponding points on the radiation distribution at the second focal plane.

Abstract: Scatterometers and methods of using scatterometry to determine several parameters of periodic microstructures, pseudo-periodic structures, and other very small structures having features sizes as small as 100 nm or less. Several specific embodiments of the present invention are particularly useful in the semiconductor industry to determine the width, depth, line edge roughness, wall angle, film thickness, and many other parameters of the features formed in microprocessors, memory devices, and other semiconductor devices. The scatterometers and methods of the invention, however, are not limited to semiconductor applications and can be applied equally well in other applications.

Abstract: Scatterometers and methods of using scatterometry to determine several parameters of periodic microstructures, pseudo-periodic structures, and other very small structures having features sizes as small as 100 nm or less. Several specific embodiments of the present invention are particularly useful in the semiconductor industry to determine the width, depth, line edge roughness, wall angle, film thickness, and many other parameters of the features formed in microprocessors, memory devices, and other semiconductor devices. The scatterometers and methods of the invention, however, are not limited to semiconductor applications and can be applied equally well in other applications.

Abstract: Scatterometers and methods of using scatterometry to determine several parameters of periodic microstructures, pseudo-periodic structures, and other very small structures having features sizes as small as 100 nm or less. Several specific embodiments of the present invention are particularly useful in the semiconductor industry to determine the width, depth, line edge roughness, wall angle, film thickness, and many other parameters of the features formed in microprocessors, memory devices, and other semiconductor devices. The scatterometers and methods of the invention, however, are not limited to semiconductor applications and can be applied equally well in other applications.

Abstract: Scatterometers and methods of using scatterometry to determine several parameters of periodic microstructures, pseudo-periodic structures, and other very small structures having features sizes as small as 100 nm or less. Several specific embodiments of the present invention are particularly useful in the semiconductor industry to determine the width, depth, line edge roughness, wall angle, film thickness, and many other parameters of the features formed in microprocessors, memory devices, and other semiconductor devices. The scatterometers and methods of the invention, however, are not limited to semiconductor applications and can be applied equally well in other applications.

Abstract: Methods for the determination of center of focus and process control for a lithographic tool. Diffraction signatures are obtained from a plurality of diffraction structures located within multiple different focus setting fields. Variability of diffraction signatures with each field are determined, by direct analysis or comparison to a library. The variation or uniformity may be represented by any measure, including the standard deviation or the range of values of a chosen feature of a library of theoretical diffraction structures or the variability or uniformity of the diffraction signatures themselves, such as by RMS difference or intensity range. The methods may be used for process control and monitoring of focus drift by determining intra-field variation of diffraction signatures of multiple diffraction structures in a series of wafers.