Abstract: A system comprises a topography measurement system configured to determine a respective height for each of a plurality of locations on a substrate; and a processor configured to: determine a height map for the substrate based on the determined heights for the plurality of locations; and determine at least one alignment parameter for the substrate by comparing the height map and a reference height map, wherein the reference height map comprises or represents heights for a plurality of locations on a reference substrate portion.

Abstract: A lithographic apparatus is used to manufacture a plurality of devices on a substrate. A height map is obtained representing a topographical variation across the substrate. Using the height map the apparatus controls imaging of a field pattern at multiple field locations across the substrate. The field pattern includes a plurality of individual device areas. For field locations near the substrate's edge, the height map data is used selectively so as to ignore topographical variations in one or more individual device areas. Whether a device area is to be ignored is determined at least partly based on the height map data obtained for the current exposure. Alternatively or in addition, the selection can be based on measurements made at the corresponding device area and field location on one or more prior substrates, and/or on the same substrate in a previous layer.

Abstract: A method of controlling a lithographic apparatus to manufacture a plurality of devices, the method including: obtaining a parameter map representing a parameter variation across a substrate by measuring the parameter at a plurality of points on the substrate; decomposing the parameter map into a plurality of components, including a first parameter map component representing parameter variations associated with the device pattern and one or more further parameter map components representing other parameter variations; deriving a scale factor, configured to correct for errors in measurement of the parameter variation, from measurements of a second parameter of a substrate; and controlling the lithographic apparatus using the parameter map and scale factor to apply a device pattern at multiple locations across the substrate.

Abstract: A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A functional relationship between local height deviations across a substrate and focus information, such as a determined focus amount, is determined for a substrate, e.g., a reference substrate. Height deviations are subsequently measured for another substrate, e.g. a production substrate. The height deviations for the subsequent substrate and the functional relationship are used to determine predicted focus information for the subsequent substrate. The predicted focus information is then used to control the lithographic apparatus to apply a product pattern to the product substrate.

Abstract: A system comprises a topography measurement system configured to determine a respective height for each of a plurality of locations on a substrate; and a processor configured to: determine a height map for the substrate based on the determined heights for the plurality of locations; and determine at least one alignment parameter for the substrate by comparing the height map and a reference height map, wherein the reference height map comprises or represents heights for a plurality of locations on a reference substrate portion.

Abstract: A lithographic apparatus is used to manufacture a plurality of devices on a substrate. A height map is obtained representing a topographical variation across the substrate. Using the height map the apparatus controls imaging of a field pattern at multiple field locations across the substrate. The field pattern includes a plurality of individual device areas. For field locations near the substrate's edge, the height map data is used selectively so as to ignore topographical variations in one or more individual device areas. Whether a device area is to be ignored is determined at least partly based on the height map data obtained for the current exposure. Alternatively or in addition, the selection can be based on measurements made at the corresponding device area and field location on one or more prior substrates, and/or on the same substrate in a previous layer.

Abstract: A lithographic apparatus applies a device pattern at multiple fields across a substrate. A height map is decomposed into a plurality of components. A first height map component represents topographical variations associated with the device pattern. One or more further height map components represent other topographical variations. Using each height map component, control set-points are calculated according to a control algorithm specific to each component. The control set-points calculated for the different height map components are then combined and used to control imaging of the device pattern to the substrate. The specific control algorithms can be different from one another, and may have differing degrees of nonlinearity. The combining of the different set-points can be linear. Focus control in the presence of device-specific topography and other local variations can be improved.

Abstract: A method of controlling a lithographic apparatus to manufacture a plurality of devices, the method including: obtaining a parameter map representing a parameter variation across a substrate by measuring the parameter at a plurality of points on the substrate; decomposing the parameter map into a plurality of components, including a first parameter map component representing parameter variations associated with the device pattern and one or more further parameter map components representing other parameter variations; deriving a scale factor, configured to correct for errors in measurement of the parameter variation, from measurements of a second parameter of a substrate; and controlling the lithographic apparatus using the parameter map and scale factor to apply a device pattern at multiple locations across the substrate.

Abstract: A lithographic apparatus uses a height sensor to obtain height sensor data representing a topographical variation across a substrate. The height sensor data is used to control focusing of a device pattern at multiple locations across the substrate. A controller identifies one or more first areas where height sensor data is judged to be reliable and one or more second areas where the height sensor data is judged to be less reliable. Substitute height data is calculated for the second areas using height sensor data for the first areas together with prior knowledge of expected device-specific topography. The focusing of the lithographic apparatus is controlled using a combination of the height data from the sensor and the substitute height data.

Abstract: A lithographic apparatus applies a device pattern at multiple fields across a substrate. A height map is decomposed into a plurality of components. A first height map component represents topographical variations associated with the device pattern. One or more further height map components represent other topographical variations. Using each height map component, control set-points are calculated according to a control algorithm specific to each component. The control set-points calculated for the different height map components are then combined and used to control imaging of the device pattern to the substrate. The specific control algorithms can be different from one another, and may have differing degrees of nonlinearity. The combining of the different set-points can be linear. Focus control in the presence of device-specific topography and other local variations can be improved.

Abstract: A lithographic apparatus applies a device pattern at multiple fields across a substrate. A height map is decomposed into a plurality of components. A first height map component represents topographical variations associated with the device pattern. One or more further height map components represent other topographical variations. Using each height map component, control set-points are calculated according to a control algorithm specific to each component. The control set-points calculated for the different height map components are then combined and used to control imaging of the device pattern to the substrate. The specific control algorithms can be different from one another, and may have differing degrees of nonlinearity. The combining of the different set-points can be linear. Focus control in the presence of device-specific topography and other local variations can be improved.

Abstract: A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A functional relationship between local height deviations across a substrate and focus information, such as a determined focus amount, is determined for a substrate, e.g., a reference substrate. Height deviations are subsequently measured for another substrate, e.g. a production substrate. The height deviations for the subsequent substrate and the functional relationship are used to determine predicted focus information for the subsequent substrate. The predicted focus information is then used to control the lithographic apparatus to apply a product pattern to the product substrate.

Abstract: A lithographic apparatus uses a height sensor to obtain height sensor data representing a topographical variation across a substrate. The height sensor data is used to control focusing of a device pattern at multiple locations across the substrate. A controller identifies one or more first areas where height sensor data is judged to be reliable and one or more second areas where the height sensor data is judged to be less reliable. Substitute height data is calculated for the second areas using height sensor data for the first areas together with prior knowledge of expected device-specific topography. The focusing of the lithographic apparatus is controlled using a combination of the height data from the sensor and the substitute height data.

Abstract: A lithographic apparatus applies a device pattern at multiple fields across a substrate. A height map is decomposed into a plurality of components. A first height map component represents topographical variations associated with the device pattern. One or more further height map components represent other topographical variations. Using each height map component, control set-points are calculated according to a control algorithm specific to each component. The control set-points calculated for the different height map components are then combined and used to control imaging of the device pattern to the substrate. The specific control algorithms can be different from one another, and may have differing degrees of nonlinearity. The combining of the different set-points can be linear. Focus control in the presence of device-specific topography and other local variations can be improved.

Abstract: A level sensor for a lithographic projection apparatus according to one embodiment of the invention includes a light source, a first reflector, a second reflector and a detector. The first reflector is positioned to direct light from the light source towards a wafer surface, and the second reflector is positioned to direct light reflected from the wafer surface to the detector. The first and second reflectors are selected to incur a minimal process dependent apparent surface depression.

Abstract: A level sensor for a lithographic projection apparatus includes a light source configured to direct light onto a substrate to be measured, a detector configured to detect light reflected from the substrate, and a processor configured to calculate a difference between measurements made with the filter in the first configuration and in the second configuration. The sensor is adjustable between a first configuration, in which the light is given a first property, and a second configuration, in which the light is given a second property. The sensor may include a polarizing filter, such that the first and second properties are different polarization states.

Abstract: A level sensor for a lithographic projection apparatus according to one embodiment of the invention includes a light source, a first reflector, a second reflector and a detector. The first reflector is positioned to direct light from the light source towards a wafer surface, and the second reflector is positioned to direct light reflected from the wafer surface to the detector. The first and second reflectors are selected to incur a minimal process dependent apparent surface depression.

Abstract: According to one embodiment, a method of calibrating level sensors of at least two lithographic projection apparatus to correct machine to machine level sensor process dependency includes using a first lithographic projection apparatus to measure a first set of leveling data for a reference substrate and a second set of leveling data for a substrate processed according to a selected process, and using a second lithographic projection apparatus to measure a third set of leveling data for the reference substrate and a fourth set of leveling data for the processed substrate. The method also includes calculating, based on the first, second, third and fourth sets of leveling data, a set of level sensor parameters corresponding to machine to machine level sensor differences for the selected process, wherein the machine to machine level sensor differences are measured and stored as intrafield values.

Abstract: A method of calibrating level sensors of at least two lithographic projection apparatus to correct machine to machine level sensor process dependency includes measuring a first set of leveling data using a first lithographic projection apparatus for a reference substrate, measuring a second set of leveling data using the first apparatus for a substrate processed according to a selected process, measuring a third set of leveling data using the second apparatus for the reference substrate, measuring a fourth set of leveling data using the second apparatus for the processed substrate, and using the first, second, third and fourth sets of leveling data to calculate the set of level sensor parameters corresponding to machine to machine level sensor differences for the selected process.

Abstract: A level sensor for a lithographic projection apparatus according to one embodiment of the invention includes a light source, a first reflector, a second reflector and a detector. The first reflector is positioned to direct light from the light source towards a wafer surface, and the second reflector is positioned to direct light reflected from the wafer surface to the detector. The first and second reflectors are selected to incur a minimal process dependent apparent surface depression.