Abstract:
PROBLEM TO BE SOLVED: To provide a lithography device capable of predicting displacement of each point of a substrate more accurately.SOLUTION: There is provided a method of estimating a value representing a level of alignment mark deformation on a substrate using an alignment system including an alignment sensor system capable of emitting light of various measurement frequency so that the light is reflected by an alignment mark and detecting a diffraction pattern formed with reflected light so as to measure the alignment position of the alignment mark on a substrate having been processed. The method includes measuring an alignment position deviation from an expected predetermined alignment position of the alignment mark for each of alignment marks related to two or more measurement frequencies by using the two or more measurement frequencies, and finding a value representing a spread of the alignment position deviation for each alignment mark so as to estimate a level of alignment mark deformation.
Abstract:
PROBLEM TO BE SOLVED: To provide a method of measuring an overlay and a target which is used for measuring the overlay, requires just a small space on a substrate, and prevents crosstalk between measuring directions. SOLUTION: An overlay marker used with a scatterometer has two two-dimensional gratings overlapping each other. The two gratings have the same pitch, and the duty ratio of the upper grating is smaller than that of the lower grating. Thus it is possible to prevent crosstalk between an X overlay measured value and a Y overlay measured value. The gratings may directly overlap each other or may be displaced from each other so as to be alternately placed in one direction or two directions. COPYRIGHT: (C)2009,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide an alternative method for calculating overlay error requiring a smaller area of a substrate. SOLUTION: Radiations are projected onto a plurality of targets on a substrate. The number of measured targets can be reduced by assuming overlay errors derived from asymmetry smoothly vary across the substrate. Therefore area of scribe lines used by target for each layer of the substrate is made smaller. COPYRIGHT: (C)2008,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a method for distinguishing a false low overlay calculation. SOLUTION: Both first and 0-th diffraction orders are detected in a scatterometer. The first diffraction order is used to detect an overlay error. The 0-th diffraction order is then used to flag if this is a false overlay error calculation of magnitude greater than a bias but smaller than a pitch of a grating. COPYRIGHT: (C)2008,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a method for measuring an overlay of a lithography device that more efficiently uses a space on a substrate and gives quick and correct results. SOLUTION: The lithography device includes a reference diffraction grating set 14 provided in the substrate, the reference diffraction grating set includes two reference diffraction gratings having a first directional line element and one reference diffraction grating having a second directional line element. A measurement diffraction grating set 12 is provided on the reference diffraction grating set, the reference diffraction grating set is provided with three measurement diffraction gratings similar to a reference diffraction grating. Two out of the measurement diffraction gratings are reversely deviated to each reference diffraction grating in the second direction. An overlay measuring device is provided to measure the asymmetry of three diffraction gratings in the reference set and the measuring set and obtain overlays in both the first and the second directions from the measured asymmetry. COPYRIGHT: (C)2008,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide an improved method for detecting an overlay error. SOLUTION: A first layer of a substrate includes a plurality of diffraction gratings each having the periodicity of P. A second layer of the substrate includes a plurality of diffraction gratings that overlap a first set of diffraction gratings and having the periodicity of NP (here, N is two or greater integer). The first set of diffraction gratings have a bias +d and a second set of diffraction gratings have a bias -d. Radiation beams are projected to the diffraction gratings and an angular resolution spectrum of the reflected radiation is detected. Next, an overlay error is calculated using the angular resolution spectrum of the reflected radiation. COPYRIGHT: (C)2008,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a compound alignment overlay target given on the substrate so as to enable the measurement of the alignment of a substrate to surroundings and the measurement of the relative alignment of a series of layers on the substrate. SOLUTION: The target is provided with an array of a structure at substantially equal intervals except a part of a structure which is an offset with the same size to a first direction and a second part of a structure which is an offset with the same size to the opposite direction. The target on the substrate can be used for the measurement of the alignment, and the same target, which is given to the second layer superimposed on the first layer, can be used for the measurement of the overlay. COPYRIGHT: (C)2008,JPO&INPIT