Abstract:
Described herein is are method for determining a stack configuration for a substrate subjected a patterning process. The method includes obtaining (i) measurement data of a stack configuration with location information on a printed substrate, (ii) a substrate model configured to predict a stack characteristic based on a location of the substrate, and (iii) a stack map including a plurality of stack configurations based on the substrate model. The method iteratively determines values of model parameters of the substrate model based on a fitting between the measurement data and the plurality of stack configurations of the stack map; and predicts an optimum stack configuration at a particular location based on the substrate model using the values of the model parameters.
Abstract:
A substrate has first and second target structures formed thereon by a lithographic process, lithographic process comprising at least two lithographic steps. Each target structure has two-dimensional periodic structure formed in a single material layer, wherein, in the first target structure, features defined in the second lithographic step are displaced relative to features defined in the first lithographic step by a first bias amount, and, in the second target structure, features defined in the second lithographic step are displaced relative to features defined in the first lithographic step by a second bias amount. An angle- resolved scatter spectrum of the first target structure and an angle-resolved scatter spectrum of the second target structure is obtained, and a measurement of a parameter of a lithographic process is derived from the measurements using asymmetry found in the scatter spectra of the first and second target structures.
Abstract:
Described is a method for determining a root cause affecting yield in a process for manufacturing devices on a substrate, the method comprising; obtaining yield distribution data comprising the distribution of a yield parameter across the substrate or part thereof; obtaining sets of metrology data, each set comprising a spatial variation of a process parameter over the substrate or part thereof corresponding to a different layer of the substrate; comparing the yield distribution data and metrology data based on a similarity metric describing a spatial similarity between the yield distribution data and an individual set out of the sets of the metrology data; and determining a first similar set of metrology data out of the sets of metrology data, being the first set of metrology data in terms of processing order for the corresponding layers, which is determined to be similar to the yield distribution data.
Abstract:
A method of measuring n values of a parameter of interest (e.g., overlay) relating to a structure forming process, where n>1. The method includes performing n measurements on each of n+1 targets, each measurement performed with measurement radiation having a different wavelength and/or polarization combination and determining the n values for a parameter of interest from the n measurements of n+1 targets, each of the n values relating to the parameter of interest for a different pair of the layers. Each target includes n+1 layers, each layer including a periodic structure, the targets including at least n biased targets having at least one biased periodic structure formed with a positional bias relative to the other layers, the biased periodic structure being in at least a different one of the layers per biased target. Also disclosed is a substrate having such a target and a patterning device for forming such a target.
Abstract:
Disclosed herein is a target structure, wherein the target structure is configured to be measured with a metrology tool, the metrology tool having a diffraction threshold; the target structure comprising: one or more patterns supported on a substrate, the one or more patterns being periodic with a first period (Pitch) in a first direction and periodic with a second period (Pitch2) in a second direction, the first direction and second direction being different and parallel to the substrate, the first period being equal to or greater than the diffraction threshold and the second period is less than the diffraction threshold.
Abstract:
Disclosed herein is a computer-implemented method to improve a lithographic process for imaging a portion of a design layout onto a substrate using a lithographic projection apparatus, the method comprising: computing a multi-variable cost function of a plurality of design variables that are characteristics of the lithographic process, and reconfiguring the characteristics of the lithographic process by adjusting the design variables until a predefined termination condition is satisfied. The multi-variable cost function may be a function of one or more pattern shift errors. Reconfiguration of the characteristics may be under one or more constraints on the one or more pattern shift errors.
Abstract:
Described is a method for predicting yield relating to a process of manufacturing semiconductor devices on a substrate, the method comprising: obtaining a trained first model which translates modeled parameters into a yield parameter, said modeled parameters comprising: a) geometrical parameters associated with one or more of: a geometric characteristic, dimension or position of a device element manufactured by the process and b) trained free parameters; obtaining process parameter data comprising process parameters characterizing the process; converting the process parameter data into values of the geometrical parameters; and predicting the yield parameter using the trained first model and the values of the geometrical parameters.
Abstract:
A method for analyzing a process, the method including: obtaining a multi-dimensional probability density function representing an expected distribution of values for a plurality of process parameters; obtaining a performance function relating values of the process parameters to a performance metric of the process; and using the performance function to map the probability density function to a performance probability function having the process parameters as arguments.
Abstract:
A method of measuring a parameter of a patterning process, the method including obtaining a measurement of a substrate processed by a patterning process, with a first metrology target measurement recipe; obtaining a measurement of the substrate with a second, different metrology target measurement recipe, wherein measurements using the first and second metrology target measurement recipes have their own distinct sensitivity to a metrology target structural asymmetry of the patterning process; and determining a value of the parameter by a weighted combination of the measurements of the substrate using the first and second metrology target measurement recipes, wherein the weighting reduces or eliminates the effect of the metrology target structural geometric asymmetry on the parameter of the patterning process determined from the measurements using the first and second metrology target measurement recipes.
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.