Maas, Abraham Johannes

A pattern (310, 610) is formed on a substrate (W) using a lithographic step (400). The pattern includes first and second sub-patterns (312, 316; 612, 616) positioned adjacent one another on the substrate and having respective first and second periodicities. The pattern is observed (402) to obtain a combined signal (403) which includes a beat component having a third periodicity at a frequency lower than that of the first and second periodicities. A measurement of performance of the lithographic process is determined (406) by reference to a phase of the beat component (405). Depending how the sub-patterns are formed, the performance parameter might be critical dimension (CD) or overlay, for example. For CD measurement, one of the sub-patterns may comprise marks each having of a portion sub-divided by product-like features. The measurement can be made using an existing alignment sensor of a lithographic apparatus. Sensitivity and accuracy of the measurement can be adjusted by selection of the first and second periodicities, and hence the third periodicity.

A pattern (310, 610) is formed on a substrate (W) using a lithographic step (400). The pattern includes first and second sub-patterns (312, 316; 612, 616) positioned adjacent one another on the substrate and having respective first and second periodicities. The pattern is observed (402) to obtain a combined signal (403) which includes a beat component having a third periodicity at a frequency lower than that of the first and second periodicities. A measurement of performance of the lithographic process is determined (406) by reference to a phase of the beat component (405). Depending how the sub-patterns are formed, the performance parameter might be critical dimension (CD) or overlay, for example. For CD measurement, one of the sub-patterns may comprise marks each having of a portion sub-divided by product-like features. The measurement can be made using an existing alignment sensor of a lithographic apparatus. Sensitivity and accuracy of the measurement can be adjusted by selection of the first and second periodicities, and hence the third periodicity.

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Zusammenfassung wird geladen …

Zusammenfassung wird geladen …

Zusammenfassung wird geladen …

Zusammenfassung wird geladen …

Zusammenfassung wird geladen …

A two-phase thermal conditioning system for thermal conditioning a part (1) of a lithographic apparatus, includes an evaporator (3) to be positioned in thermal contact with the part of the lithographic apparatus for extracting heat from the part by evaporation of a fluid inside the evaporator; a condenser (5) to be positioned at a distance from the part of the lithographic apparatus for removing heat from the fluid inside the condenser by condensation of the fluid inside the condenser; fluid lines (7,8,9) arranged between the evaporator and the condenser to form a circuit in which fluid is able to flow; a pump (14) arranged in the circuit to circulate the fluid in the circuit; an accumulator (16) configured to hold fluid, wherein the accumulator is in fluid communication with the circuit and comprises a heat exchanger (18) to transfer heat from or to fluid inside the accumulator; a temperature sensor (23) configured to provide a measurement signal representative of the temperature of the fluid; and a controller (27) configured to maintain a substantially constant temperature of the fluid inside the circuit by regulating the amount of heat transferred by the heat exchanger from or to fluid inside the accumulator based on the measurement signal.

A two-phase thermal conditioning system for thermal conditioning a part (1) of a lithographic apparatus, includes an evaporator (3) to be positioned in thermal contact with the part of the lithographic apparatus for extracting heat from the part by evaporation of a fluid inside the evaporator; a condenser (5) to be positioned at a distance from the part of the lithographic apparatus for removing heat from the fluid inside the condenser by condensation of the fluid inside the condenser; fluid lines (7,8,9) arranged between the evaporator and the condenser to form a circuit in which fluid is able to flow; a pump (14) arranged in the circuit to circulate the fluid in the circuit; an accumulator (16) configured to hold fluid, wherein the accumulator is in fluid communication with the circuit and comprises a heat exchanger (18) to transfer heat from or to fluid inside the accumulator; a temperature sensor (23) configured to provide a measurement signal representative of the temperature of the fluid; and a controller (27) configured to maintain a substantially constant temperature of the fluid inside the circuit by regulating the amount of heat transferred by the heat exchanger from or to fluid inside the accumulator based on the measurement signal.