Abstract: A metrology apparatus for and a method of determining a characteristic of interest relating to at least one structure on a substrate. The metrology apparatus comprises a sensor and an optical system. The sensor is for detecting characteristics of radiation impinging on the sensor. The optical system comprises an illumination path and a detection path. The optical system is configured to illuminate the at least one structure with radiation received from a source via the illumination path. The optical system is configured to receive radiation scattered by the at least one structure and to transmit the received radiation to the sensor via the detection path.

Abstract: There is disclosed a method of measuring a process parameter for a manufacturing process involving lithography. In a disclosed arrangement the method comprises performing first and second measurements of overlay error in a region on a substrate, and obtaining a measure of the process parameter based on the first and second measurements of overlay error. The first measurement of overlay error is designed to be more sensitive to a perturbation in the process parameter than the second measurement of overlay error by a known amount.

Abstract: A metrology tool for determining a parameter of interest of a structure fabricated on a substrate, the metrology tool comprising: an illumination optical system for illuminating the structure with illumination radiation under a non-zero angle of incidence; a detection optical system comprising a detection optical sensor and at least one lens for capturing a portion of illumination radiation scattered by the structure and transmitting the captured radiation towards the detection optical sensor, wherein the illumination optical system and the detection optical system do not share an optical element.

Abstract: A scatterometer for measuring a property of a target on a substrate includes a radiation source, a detector, and a processor. The radiation source produces a radiated spot on the target. The scatterometer adjusts a position of the radiated spot along a first direction across the target and along a second direction that is at an angle with respect to the first direction. The detector receives radiation scattered by the target. The received radiation is associated with positions of the radiated spot on the target along at least the first direction. The detector generates measurement signals based on the positions of the radiated spot on the target. The processor outputs, based on the measurement signals, a single value that is representative of the property of the target. The processor also combines the measurement signals to output a combined signal and derives, based on the combined signal, the single value.

Abstract: A method provides the steps of receiving an image from a metrology tool, determining individual units of said image and discriminating the units which provide accurate metrology values. The images are obtained by measuring the metrology target at multiple wavelengths. The discrimination between the units, when these units are pixels in said image, is based on calculating a degree of similarity between said units.

Abstract: A method includes receiving an image formed in a metrology apparatus wherein the image comprises at least the resulting effect of at least two diffraction orders, and processing the image wherein the processing comprises at least a filtering step, for example a Fourier filter. The process of applying a filter may be obtained also by placing an aperture in the detection branch of the metrology apparatus.

Abstract: A method including: obtaining a detected representation of radiation redirected by each of a plurality of structures from a substrate additionally having a device pattern thereon, wherein each structure has an intentional different physical configuration of the respective structure than the respective nominal physical configuration of the respective structure, wherein each structure has geometric symmetry at the respective nominal physical configuration, wherein the intentional different physical configuration of the structure causes an asymmetric optical characteristic distribution and wherein a patterning process parameter measures change in the physical configuration; and determining a value, based on the detected representations and based on the intentional different physical configurations, to setup, monitor or correct a measurement recipe for determining the patterning process parameter.

Abstract: A metrology tool for determining a parameter of interest of a structure fabricated on a substrate, the metrology tool comprising: an illumination optical system for illuminating the structure with illumination radiation under a non-zero angle of incidence; a detection optical system comprising a detection optical sensor and at least one lens for capturing a portion of illumination radiation scattered by the structure and transmitting the captured radiation towards the detection optical sensor, wherein the illumination optical system and the detection optical system do not share an optical element.

Abstract: A diffraction measurement target that has at least a first sub-target and at least a second sub-target, and wherein (1) the first and second sub-targets each include a pair of periodic structures and the first sub-target has a different design than the second sub-target, the different design including the first sub-target periodic structures having a different pitch, feature width, space width, and/or segmentation than the second sub-target periodic structure or (2) the first and second sub-targets respectively include a first and second periodic structure in a first layer, and a third periodic structure is located at least partly underneath the first periodic structure in a second layer under the first layer and there being no periodic structure underneath the second periodic structure in the second layer, and a fourth periodic structure is located at least partly underneath the second periodic structure in a third layer under the second layer.

Abstract: A diffraction measurement target that has at least a first sub-target and at least a second sub-target, and wherein (1) the first and second sub-targets each include a pair of periodic structures and the first sub-target has a different design than the second sub-target, the different design including the first sub-target periodic structures having a different pitch, feature width, space width, and/or segmentation than the second sub-target periodic structure or (2) the first and second sub-targets respectively include a first and second periodic structure in a first layer, and a third periodic structure is located at least partly underneath the first periodic structure in a second layer under the first layer and there being no periodic structure underneath the second periodic structure in the second layer, and a fourth periodic structure is located at least partly underneath the second periodic structure in a third layer under the second layer.

Abstract: A method to measure a parameter of a manufacturing process, the method including illuminating a target with radiation, detecting scattered radiation from the target, and determining the parameter of interest from an asymmetry of the detected radiation.

Abstract: A defect prediction method for a device manufacturing process involving processing a portion of a design layout onto a substrate, the method including: identifying a hot spot from the portion of the design layout; determining a range of values of a processing parameter of the device manufacturing process for the hot spot, wherein when the processing parameter has a value outside the range, a defect is produced from the hot spot with the device manufacturing process; determining an actual value of the processing parameter; determining or predicting, using the actual value, existence, probability of existence, a characteristic, or a combination thereof, of a defect produced from the hot spot with the device manufacturing process.

Abstract: Methods and apparatus are disclosed for determining a characteristic of a structure. In one arrangement, the structure is illuminated with first illumination radiation to generate first scattered radiation. A first interference pattern is formed by interference between a portion of the first scattered radiation reaching a sensor and first reference radiation. The structure is also illuminated with second illumination radiation from a different direction. A second interference pattern is formed using second reference radiation. The first and second interference patterns are used to determine the characteristic of the structure. Azimuthal angles of the first and second reference radiations onto the sensor are different.

Abstract: Disclosed is a method and associated apparatus for measuring a characteristic of interest relating to a structure on a substrate. The method comprises calculating a value for the characteristic of interest directly from the effect of the characteristic of interest on at least the phase of illuminating radiation when scattered by the structure, subsequent to illuminating said structure with said illuminating radiation.

Abstract: A method including: obtaining a detected representation of radiation redirected by each of a plurality of structures from a substrate additionally having a device pattern thereon, wherein each structure has an intentional different physical configuration of the respective structure than the respective nominal physical configuration of the respective structure, wherein each structure has geometric symmetry at the respective nominal physical configuration, wherein the intentional different physical configuration of the structure causes an asymmetric optical characteristic distribution and wherein a patterning process parameter measures change in the physical configuration; and determining a value, based on the detected representations and based on the intentional different physical configurations, to setup, monitor or correct a measurement recipe for determining the patterning process parameter.

Abstract: Methods and apparatus are disclosed for determining a characteristic of a structure. In one arrangement, the structure is illuminated with first illumination radiation to generate first scattered radiation. A first interference pattern is formed by interference between a portion of the first scattered radiation reaching a sensor and first reference radiation. The structure is also illuminated with second illumination radiation from a different direction. A second interference pattern is formed using second reference radiation. The first and second interference patterns are used to determine the characteristic of the structure. Azimuthal angles of the first and second reference radiations onto the sensor are different.

Abstract: A method including evaluating a plurality of substrate measurement recipes for measurement of a metrology target processed using a patterning process, against stack sensitivity and overlay sensitivity, and selecting one or more substrate measurement recipes from the plurality of substrate measurement recipes that have a value of the stack sensitivity that meets or crosses a threshold and that have a value of the overlay sensitivity within a certain finite range from a maximum or minimum value of the overlay sensitivity.

Abstract: The disclosure relates to measuring a parameter of a lithographic process and a metrology apparatus. In one arrangement, radiation from a radiation source is modified and used to illuminate a target formed on a substrate using the lithographic process. Radiation scattered from a target is detected and analyzing to determine the parameter. The modification of the radiation comprises modifying a wavelength spectrum of the radiation to have a local minimum between a global maximum and a local maximum, wherein the power spectral density of the radiation at the local minimum is less than 20% of the power spectral density of the radiation at the global maximum and the power spectral density of the radiation at the local maximum is at least 50% of the power spectral density of the radiation at the global maximum.

Abstract: A method of measuring overlay uses a plurality of asymmetry measurements from locations (LOI) on a pair of sub-targets (1032, 1034) formed on a substrate (W). For each sub-target, the plurality of asymmetry measurements are fitted to at least one expected relationship (1502, 1504) between asymmetry and overlay, based on a known bias variation deigned into the sub-targets. Continuous bias variation in one example is provided by varying the pitch of top and bottom gratings (P1/P2). Bias variations between the sub-targets of the pair are equal and opposite (P2/P1). Overlay (OV) is calculated based on a relative shifht (xs) between the fitted relationships for the two sub-targets. The step of fitting asymmetry measurements to at least one expected relationship includes wholly or partially discounting measurements (1506, 1508, 1510) that deviate from the expected relationship and/or fall outside a particular segment of the fitted relationship.

Abstract: Disclosed is a method and associated inspection apparatus for detecting variations on a surface of a substrate. The method comprises providing patterned inspection radiation to a surface of a substrate. The inspection radiation is patterned such that an amplitude of a corresponding enhanced field is modulated in a manner corresponding to the patterned inspection radiation. The scattered radiation resultant from interaction between the enhanced field and the substrate surface is received and variations on the surface of the substrate are detected based on the interaction between the enhanced field and the substrate surface. Also disclosed is a method of detecting any changes to at least one characteristic of received radiation, the said changes being induced by the generation of a surface plasmon at said surface of the optical element.