Lithographic apparatus, method of determining a model parameter, device manufacturing method, and device manufactured thereby
First Claim
1. A method of determining at least one parameter of an object model used in a device manufacturing process, the object model providing information about a position of an object, the object having a plurality of alignment marks with desired positions that are known, the method comprising:
- receiving signals from the plurality of alignment marks;
determining a strength of the received signals;
determining weighing coefficients based on the strength of the received signals;
measuring a plurality of positional parameters for the plurality of alignment marks, the plurality of positional parameters being weighted with the weighing coefficients;
determining the at least one parameter of the object model based on the measured plurality of positional parameters, including determining a numerical value of at least one of the weighing coefficients the at least one parameter of the object model simultaneously; and
using the object model in the device manufacturing process.
1 Assignment
0 Petitions
Accused Products
Abstract
A method according to one embodiment of the invention relates to determining at least one parameter of a model that provides information about a position of an object. The object may include a plurality of alignment marks of which desired positions are known. The method includes measuring a plurality of positional parameters for each alignment mark. Based on the measured plurality of positional parameters, which are weighted with weighing coefficients, at least one parameter of the model of the object is determined. The numerical value of each weighing coefficient is determined together with the at least one parameter of the model.
26 Citations
25 Claims
-
1. A method of determining at least one parameter of an object model used in a device manufacturing process, the object model providing information about a position of an object, the object having a plurality of alignment marks with desired positions that are known, the method comprising:
-
receiving signals from the plurality of alignment marks; determining a strength of the received signals; determining weighing coefficients based on the strength of the received signals; measuring a plurality of positional parameters for the plurality of alignment marks, the plurality of positional parameters being weighted with the weighing coefficients; determining the at least one parameter of the object model based on the measured plurality of positional parameters, including determining a numerical value of at least one of the weighing coefficients the at least one parameter of the object model simultaneously; and using the object model in the device manufacturing process. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A lithographic device configured to receive a substrate having a plurality of alignment marks located thereon for which desired positions are known, the lithographic device comprising:
-
a beam generator that is arranged to project an alignment beam at the plurality of alignment marks to generate positional parameters for the alignment marks; a sensor that is arranged to measure the positional parameters; and a processing unit that receives the positional parameters and a signal strength indicator from the sensor, determines weighing coefficients for the positional parameters and determines at least one parameter of a substrate model to provide information about a position of the alignment mark based on the measured positional parameters, wherein the processing unit determines the weighing coefficients based on signal strength indicator received from the sensor, and wherein the processor unit is configured to determine a numerical value of at least one of the weighing coefficients the at least one parameter of the substrate model simultaneously. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
-
-
20. A method of determining a value for a parameter of an object model used in a device manufacturing process, the object model providing information about a position of an object having a plurality of alignment marks thereon, the method comprising:
-
receiving signals from the plurality of alignment marks; obtaining a plurality of measured positions for a plurality of alignment marks from the received signals; solving an expression to obtain a value for the parameter of the object model, the expression including the plurality of measured positions, at least one desired position for the plurality of alignment marks, and a plurality of weighting coefficients, each weighting coefficient corresponding to at least one of the plurality of measured positions, wherein the weighting coefficients are determined based on a strength of the received signals, wherein a value of at least one of the weighting coefficients is based on the plurality of measured positions and the at least one desired position for the plurality of alignment marks; and using the object model in the device manufacturing process. - View Dependent Claims (21, 22, 23, 24)
-
-
25. A method of determining at least one parameter of an object model used in a device manufacturing process, the object model providing information about positions of a plurality of alignment marks that are located on an object, the method comprising:
-
projecting an alignment beam at selected ones of the plurality of alignment marks to generate one or more diffraction orders; receiving signals corresponding to the one or more diffraction orders; determining a strength of the received signals; assigning a weighing coefficient to each of the one or more diffraction orders based on the strength of the received signals; measuring a plurality of positional parameters for the selected ones of the plurality of alignment marks, the plurality of positional parameters being derived from corresponding weighing coefficients; determining the at least one parameter of the object model based on the measured plurality of positional parameters, including determining a numerical value of at least one of the weighing coefficients the at least one parameter of the object model simultaneously; and using the object model in the device manufacturing process.
-
Specification