摘要:
A system and method use a substrate with a pattern of individual, indiscrete alignment marks, i.e., the marks are separate and distinct from each other, and each mark is not divided into component parts. The pattern of marks is distributed over an area of the substrate, and the method also comprises the steps of providing a beam of radiation using an illumination system and an array of individually controllable elements to impart the beam with a pattern in its cross-section, providing a projection system to project the patterned beam onto the substrate, and providing a movement system to effect relative movement between the substrate and the projection system. A detection system, able to detect the alignment marks individually, is also provided, and the method includes using the detection system to detect the marks to determine a relative position of the substrate to the projection system, using the movement system to position the substrate relative to the projection system, and using the projection system to project the patterned beam of radiation onto a target portion of the substrate. The pattern comprises one or more rows of simple alignment marks, such as spots and short linear marks.
摘要:
A pattern formed on a substrate includes first and second sub-patterns positioned adjacent one another and having respective first and second periodicities. The pattern is observed to obtain a combined signal 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 by reference to a phase of the beat component. 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.
摘要:
A method for manufacturing a device includes providing a substrate, the substrate including a plurality of exposure fields, each exposure field including one or more target portions and at least one mark structure, the mark structure being arranged as positional mark for the exposure field; scanning and measuring the mark of each exposure field to obtain alignment information for the respective exposure field; determining an absolute position of each exposure field from the alignment information for the respective exposure field; determining a relative position of each exposure field with respect to at least one other exposure field by use of additional information on the relative parameters of the exposure field and the at least one other exposure field relative to each other; and combining the absolute positions and the determined relative positions into improved absolute positions for each of the plurality of exposure fields.
摘要:
An alignment measurement arrangement includes a source, an optical system and a detector. The source generates a radiation beam with a plurality of wavelength ranges. The optical system receives the radiation beam, produces an alignment beam, directs the alignment beam to a mark located on an object, receives alignment radiation back from the mark, and transmits the received radiation. The detector receives the alignment radiation and detects an image of the alignment mark and outputs a plurality of alignment signals, r, each associated with one of the wavelength ranges. A processor, in communication with the detector, receives the alignment signals, determines signal qualities of the alignment signals; determines aligned positions of the alignment signals, and calculates a position of the alignment mark based on the signal qualities, aligned positions, and a model relating the aligned position to the range of wavelengths and mark characteristics, including mark depth and mark asymmetry.
摘要:
An alignment measurement system measures an alignment target on an object. A measurement illuminates the target and is reflected. The reflected measurement beam is split and its parts are differently polarized. A detector receives the reflected measurement beam. A processing unit determines alignment on the basis of the measurement beam received by the detector. An alternative arrangement utilizes an optical dispersive fiber to guide a multi-wavelength measurement beam reflected from the object to a detector.