Source: http://www.google.es/patents/US7440105?dq=flatulence
Timestamp: 2015-10-13 23:02:21
Document Index: 462897607

Matched Legal Cases: ['Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60']

Patente US7440105 - Continuously varying offset mark and methods of determining overlay - Google PatentesB�squeda Im�genes Maps Play YouTube Noticias Gmail Drive M�s »Iniciar sesi�n B�squeda avanzada de patentesPatentesThe present invention relates to overlay marks and methods for determining overlay error. One aspect of the present invention relates to a continuously varying offset mark. The continuously varying offset mark is a single mark that includes over laid periodic structures, which have offsets that vary...http://www.google.es/patents/US7440105?utm_source=gb-gplus-sharePatente US7440105 - Continuously varying offset mark and methods of determining overlay B�squeda avanzada de patentes N�mero de publicaci�nUS7440105 B2Tipo de publicaci�nConcesi�n N�mero de solicitudUS 11/060,588 Fecha de publicaci�n21 Oct 2008 Fecha de presentaci�n16 Feb 2005 Fecha de prioridad5 Dic 2002TarifaPagadasTambi�n publicado comoEP1716389A2, EP1716389A4, US20050195398, WO2005079498A2, WO2005079498A3 N�mero de publicaci�n060588, 11060588, US 7440105 B2, US 7440105B2, US-B2-7440105, US7440105 B2, US7440105B2 InventoresMichael E. Adel, Joel L. Seligson, Daniel Kandel Cesionario originalKla-Tencor Technologies CorporationExportar citaBiBTeX, EndNote, RefManCitas de patentes (106), Otras citas (56), Citada por (24), Clasificaciones (20), Eventos legales (2) Enlaces externos: USPTO, Cesi�n de USPTO, EspacenetContinuously varying offset mark and methods of determining overlay
US 7440105 B2 Resumen
The present invention relates to overlay marks and methods for determining overlay error. One aspect of the present invention relates to a continuously varying offset mark. The continuously varying offset mark is a single mark that includes over laid periodic structures, which have offsets that vary as a function of position. By way of example, the periodic structures may correspond to gratings with different values of a grating characteristic such as pitch. Another aspect of the present invention relates to methods for determining overlay error from the continuously varying offset mark. The method generally includes determining the center of symmetry of the continuously varying offset mark and comparing it to the geometric center of the mark. If there is zero overlay, the center of symmetry tends to coincide with the geometric center of the mark. If overlay is non zero (e.g., misalignment between two layers), the center of symmetry is displaced from the geometric center of the mark. The displacement in conjunction with the preset gain of the continuously varying offset mark is used to calculate the overlay error.
Im�genes(30) Reclamaciones(12)
a first periodic structure located on a first layer, the first periodic structure having a first value of an attribute of a periodic structure; and
a second periodic structure located on a second layer, and positioned over the first periodic structure, the second periodic structure having at least a second value of the attribute of a periodic structure, wherein the first and second values have a substantially small difference and wherein each of the first and second periodic structures is for measuring overlay in two directions and wherein the attribute is rotation or pitch,
wherein the length of the first and second periodic structures is independent from the substantially small difference.
2. The overlay target as recited in claim 1 wherein the second value is larger than the first value.
3. The overlay target as recited in claim 1 wherein the second value is smaller than the first value.
4. The overlay target as recited in claim 1 wherein the first and second periodic structures each consist of a plurality of sub segments oriented in two directions.
5. The overlay target as recited in claim 1 wherein the difference between the first and second values is less than 10%.
6. The overlay target as recited in claim 1 wherein the difference between the first and second values is less than 5%.
7. The overlay target as recited in claim 1 wherein the difference between the first and second values is less than or equal to 1.0%.
8. The overlay target as recited in claim 1, wherein the small difference is configured to generate a preset gain for the overlay target.
9. The overlay target as recited in claim 1 wherein the difference between the first and second values is between about 0.01% and about 10%.
10. The overlay target as recited in claim 9 wherein the difference between the first and second values is between about 0.10% and about 0.99%.
11. An overlay target comprising:
a first portion located on a first layer, the first portion including a first grating having a first value of a pitch;
a second portion located on a second layer and centered above the first portion, the first and second portions having substantially a same dimensional profile, the second portion including a second grating and third grating that are positioned side by side, the second grating having a second value of a pitch, and the third grating having a third value of a pitch, the second value being slightly larger than the first value, the third value being slightly smaller than the first value,
wherein the second grating and the third grating extend substantially over the first grating.
12. The overlay target as recited in claim 11 wherein a difference between the first value and the second and third values is 1.0%.
This application claims priority to U.S. Provisional Patent Application No. 60/546,024 entitled “APPARATUS AND METHODS FOR DETERMINING OVERLAY AND USES OF SAME”, filed Feb. 18, 2004, which application is herein incorporated by reference.
This application is a continuation-in-part of U.S. patent application Ser. No. 10/729,838 entitled “APPARATUS AND METHODS FOR DETECTING OVERLAY ERRORS USING SCATTEROMETRY”, filed Dec. 5, 2003 now U.S. Pat. No. 7,317,531, and which claims priority to the following co-pending U.S. Provisional Patent Applications: (1) Application No. 60/431,314 entitled METHOD FOR DETERMINING OVERLAY ERROR BY COMPARISON BETWEEN SCATTEROMETRY SIGNALS FROM MULTIPLE OVERLAY MEASUREMENT TARGETS, by Walter D. Mieher et al., filed 5 Dec. 2002, (2) Application No. 60/440,970 entitled METHOD FOR DETERMINING OVERLAY ERROR BY COMPARISON BETWEEN SCATTEROMETRY SIGNALS FROM MULTIPLE OVERLAY MEASUREMENT TARGETS WITH SPECTROSCOPIC IMAGING OR SPECTROSCOPIC SCANNING, by Walter D. Mieher, filed 17 Jan. 2003, (3) Application No. 60/504,093 entitled APPARATUS AND METHODS FOR DETECTING OVERLAY ERRORS USING SCATTEROMETRY, by Walter D. Mieher, filed 19 Sep. 2003, (4) Application No. 60/449,496 entitled METHOD AND SYSTEM FOR DETERMINING OVERLAY ERRORS BASED ON SCATTEROMETRY SIGNALS ACQUIRED FROM MULTIPLE OVERLAY MEASUREMENT PATTERNS, by Walter D. Mieher, filed 22 Feb. 2003, and (5) Application No. 60/498,524, filed 27 Aug. 2003, entitled “METHOD AND APPARATUS COMBINING IMAGING AND SCATTEROMETRY FOR OVERLAY METROLOGY”, by Mike Adel. These applications are herein incorporated by reference in their entirety.
This application is related to U.S. patent application Ser. No. 10/785,396 entitled “APPARATUS AND METHODS FOR DETECTING OVERLAY ERRORS USING SCATTEROMETRY”, filed Feb. 22, 2004, which application is herein incorporated by reference.
The invention relates, in one embodiment, to a method of extracting overlay information from an overlay target having over laid first and second periodic structures designed with a preset gain factor. The method includes obtaining a spatial array of optical data along the overlay target. The method also includes determining the center of symmetry of the overlay target based on the spatial array of optical data. The method further includes calculating a distance X between the center of symmetry and the geometric center of the overlay target. The method additionally includes determining the overlay error by dividing the distance X by the preset gain factor.
The invention relates, in another embodiment, to an overlay target. The overlay target includes a first periodic structure located on a first layer. The first periodic structure has a first value of an attribute of a periodic structure. The overlay target also includes a second periodic structure located on a second layer, and positioned over the first periodic structure. The second periodic structure has a second value of the attribute of a periodic structure. The first and second values have a substantially small difference.
The invention relates, in another embodiment, to an overlay target. The overlay target includes a first grating positioned in a first layer and having a first pitch. The overlay target also includes a second grating positioned in a second layer and having a second pitch. The first and second pitches have a substantially small difference.
The invention relates, in another embodiment, to an overlay target. The overlay target includes a first portion located on a first layer. The first portion includes a first grating having a first value of a grating characteristic. The overlay target also includes a second portion located on a second layer and centered above the first portion. The first and second portions have substantially the same dimensional profile. The second portion includes a second grating and third grating that are positioned side by side. The second grating has a second value of a grating characteristic, and the third grating has a third value of a grating characteristic. The second value is slightly larger than the first value, and the third value is slightly smaller than the first value.
The invention relates, in another embodiment, to a method for determining overlay error. The method includes providing an overlay target comprising over laid periodic structures. Each of the overlaid periodic structures has a different value for an attribute of the periodic structures. The different values for the attribute of the periodic structures having a substantially small difference. The method also includes obtaining an array of spectra across the overlay target. The method further includes finding the null point of the array of spectra. The null point being the point that produces a difference spectra that is substantially zero over the entire spectral range. The null point indicating the center of symmetry of the overlay target. The method additionally includes calculating a distance X between the center of symmetry and the geometric center of the overlay target. The method also includes calculating a ratio D between one of the values or an average of the values and the difference between the first and second values. Moreover, the method includes determining the overlay error by dividing the distance X by the ratio D.
FIG. 15 is a flow diagram illustrating a method of determining overlay error, in accordance with one embodiment of the present invention.
FIG. 16 is a diagram of a one dimensional overlay target, in accordance with one embodiment of the present invention.
FIGS. 17A and 17B are top view diagrams of a one-dimensional overlay target, in accordance with one embodiment of the present invention.
FIGS. 18A and 18B are side view diagram of a one dimensional overlay target, in accordance with one embodiment of the present invention.
FIGS. 19A a