摘要:
A method of measurement of at-resolution overlay offset may be implemented in a scatterometer. At least three targets are provided on a wafer, each target comprising a first marker grating and a second interleaved marker grating and each target having a different overlay bias between its first and second marker. The first and second markers are provided by subsequent lithography steps in a double patterning lithographic process. The targets are measured with a scatterometer and for each target a measured CD of at least one of the markers is determined using reconstruction. The CD of the first marker may be fixed in the reconstruction. The measured CDs and at least one of the overlay biases is used to determine an overlay result corresponding to a minimum measured CD. The overlay result may be determined by fitting a function such as a parabola to the measured CDs and the overlay biases and determining the overlay at the minimum of the fitted function.
摘要:
A method of measurement of at-resolution overlay offset may be implemented in a scatterometer. At least three targets are provided on a wafer, each target comprising a first marker grating and a second interleaved marker grating and each target having a different overlay bias between its first and second marker. The first and second markers are provided by subsequent lithography steps in a double patterning lithographic process. The targets are measured with a scatterometer and for each target a measured CD of at least one of the markers is determined using reconstruction. The CD of the first marker may be fixed in the reconstruction. The measured CDs and at least one of the overlay biases is used to determine an overlay result corresponding to a minimum measured CD. The overlay result may be determined by fitting a function such as a parabola to the measured CDs and the overlay biases and determining the overlay at the minimum of the fitted function.
摘要:
In a method for determining one or more properties of a substrate, scatterometry spectra can be measured from one or more targets on the substrate. Reconstructions of each of said spectra can be performed to derive one or more values for the property of the substrate, by comparing representations of each of the measured spectra with one or more modeled representations of spectra calculated using variable parameter values. At least one parameter in the reconstruction for each spectrum can be linked to the value of the parameter used in the reconstruction for a different spectrum.
摘要:
A plurality of targets including a second population superimposed on a first population are formed. In the first target the second population has an asymmetry with respect to the first population. In the second target the second population has a different asymmetry with respect to the first population. Reflected radiation is detected from both the targets and used to determine different characteristics of the underlying populations.
摘要:
In order to determine whether an exposure apparatus is outputting the correct dose of radiation and its projection system is focusing the radiation correctly, a test pattern is used on a mask for printing a specific marker onto a substrate. This marker is then measured by an inspection apparatus, such as a scatterometer, to determine whether there are errors in focus and dose and other related properties. The test pattern is configured such that changes in focus and dose may be easily determined by measuring the properties of a pattern that is exposed using the mask. The test pattern may be a 2D pattern where physical or geometric properties, e.g., pitch, are different in each of the two dimensions. The test pattern may also be a one-dimensional pattern made up of an array of structures in one dimension, the structures being made up of at least one substructure, the substructures reacting differently to focus and dose and giving rise to an exposed pattern from which focus and dose may be determined.
摘要:
In a method for determining one or more properties of a substrate, scatterometry spectra can be measured from one or more targets on the substrate. Reconstructions of each of said spectra can be performed to derive one or more values for the property of the substrate, by comparing representations of each of the measured spectra with one or more modeled representations of spectra calculated using variable parameter values. At least one parameter in the reconstruction for each spectrum can be linked to the value of the parameter used in the reconstruction for a different spectrum.
摘要:
A plurality of targets including a second population superimposed on a first population are formed. In the first target the second population has an asymmetry with respect to the first population. In the second target the second population has a different asymmetry with respect to the first population. Reflected radiation is detected from both the targets and used to determine different characteristics of the underlying populations.
摘要:
During a multiple patterning process every nth element of the pattern is removed. The removal of the elements of the patterns happens after the pattern has been printed into the radiation sensitive material or etched into substrate. Advantageously, the original mask is not varied, and another exposure step is used to remove the elements of the pattern.
摘要:
The present invention relates to a method for determining parameter value related to a lithographic process by which a marker structure has been applied on a product substrate based on obtaining calibration measurement data, with an optical detection apparatus, from a calibration marker structure set on a calibration substrate, including at least one calibration marker structure created using different known values of the parameter. The method further determines a mathematical model by using said known values of said at least one parameter and by employing a regression technique on said calibration measurement data, obtains product measurement data, with said optical detection apparatus, from a product marker structure on the product substrate, with at least one product marker structure being exposed with an unknown value of said at least one parameter. Furthermore, the method determines the unknown value of at least one parameter for the product substrate from the obtained product measurement data, wherein the optical detection apparatus may be a SEM and the obtained data includes an image obtained by the SEM.
摘要:
In order to determine whether an exposure apparatus is outputting the correct dose of radiation and its projection system is focusing the radiation correctly, a test pattern is used on a mask for printing a specific marker onto a substrate. This marker is then measured by an inspection apparatus, such as a scatterometer, to determine whether there are errors in focus and dose and other related properties. The test pattern is configured such that changes in focus and dose may be easily determined by measuring the properties of a pattern that is exposed using the mask. The test pattern may be a 2D pattern where physical or geometric properties, e.g., pitch, are different in each of the two dimensions. The test pattern may also be a one-dimensional pattern made up of an array of structures in one dimension, the structures being made up of at least one substructure, the substructures reacting differently to focus and dose and giving rise to an exposed pattern from which focus and dose may be determined.