Abstract: A semiconductor wafer may include a dummy field configured to enable overlay measurements. The enhanced dummy field may include a plurality of encoding blocs that enable OVL measurements to be made throughout the enhanced dummy field.

Abstract: A semiconductor target for determining a relative shift between two or more successive layers of a substrate is provided. The target comprises a plurality of first structures formed in a first layer, and the first structures have a first center of symmetry (COS). The target further comprises a plurality of second structures formed in a second layer, and the second structures have second COS. The difference between the first COS and the second COS corresponds to an overlay error between the first and second layer and wherein the first and second structures have a 180° rotational symmetry, without having a 90° rotational symmetry, with respect to the first and second COS, respectively.

Abstract: Disclosed are overlay targets having flexible symmetry characteristics and metrology techniques for measuring the overlay error between two or more successive layers of such targets. Techniques for imaging targets with flexible symmetry characteristics and analyzing the acquired images to determine overlay or alignment error are disclosed.

Abstract: Disclosed are apparatus and methods for optimizing a metrology tool, such as an optical or scanning electron microscope so that minimum human intervention is achievable during the optimization. In general, a set of specifications and an initial input data are initially provided for a particular target. The specifications provide limits for characteristics of images that are to be measured by the metrology tool. The metrology tool is then automatically optimized for measuring the particular target so as to meet one or more of the provided specifications without further significant human intervention with respect to the metrology tool. In one aspect, the input data provided prior to the automated optimization procedure includes a plurality of target locations and a synthetic image of the particular target.

Abstract: Disclosed are techniques, apparatus, and targets for determining overlay error between two layers of a sample. A plurality of targets is provided. Each target includes a portion of the first and second structures and each is designed to have an offset between its first and second structure portions. The targets are illuminated with electromagnetic radiation to thereby obtain spectra from each target at a ?1st diffraction order and a +1st diffraction order.

Abstract: An overlay mark for determining the relative shift between two or more successive layers of a substrate and methods for using such overlay mark are disclosed. In one embodiment, the overlay mark includes at least one test pattern for determining the relative shift between a first and a second layer of the substrate in a first direction. The test pattern includes a first set of working zones and a second set of working zones. The first set of working zones are disposed on a first layer of the substrate and have at least two working zones diagonally opposed and spatially offset relative to one another. The second set of working zones are disposed on a second layer of the substrate and have at least two working zones diagonally opposed and spatially offset relative to one another. The first set of working zones are generally angled relative to the second set of working zones thus forming an “X” shaped test pattern.

Abstract: Disclosed are techniques and apparatus are provided for determining overlay error or pattern placement error (PPE) across the field of a scanner which is used to pattern a sample, such as a semiconductor wafer or device. This determination is performed in-line on the product wafer or device. That is, the targets on which overlay or PPE measurements are performed are provided on the product wafer or device itself. The targets are either distributed across the field by placing the targets within the active area or by distributing the targets along the streets (the strips or scribe areas) which are between the dies of a field. The resulting overlay or PPE that is obtained from targets distributed across the field may then be used in a number of ways to improve the fabrication process for producing the sample.

Abstract: An overlay method for determining the overlay error of a device structure formed during semiconductor processing is disclosed. The overlay method includes producing calibration data that contains overlay information relating the overlay error of a first target at a first location to the overlay error of a second target at a second location for a given set of process conditions. The overlay method also includes producing production data that contains overlay information associated with a production target formed with the device structure. The overlay method further includes correcting the overlay error of the production target based on the calibration data.

Abstract: In one embodiment, a metrology target for determining a relative shift between two or more successive layers of a substrate may comprise; an first structure on a first layer of a substrate and an second structure on a successive layer to the first layer of the substrate arranged to determine relative shifts in alignment in both the x and y directions of the substrate by analyzing the first structure and second structure overlay.

Abstract: Disclosed are techniques, apparatus, and targets for determining overlay error between two layers of a sample. A plurality of targets is provided. Each target includes a portion of the first and second structures and each is designed to have an offset between its first and second structure portions. The targets are illuminated with electromagnetic radiation to thereby obtain spectra from each target at a ?1st diffraction order and a +1st diffraction order.

Abstract: In one embodiment, a metrology target for determining a relative shift between two or more successive layers of a substrate may comprise; an first structure on a first layer of a substrate and an second structure on a successive layer to the first layer of the substrate arranged to determine relative shifts in alignment in both the x and y directions of the substrate by analyzing the first structure and second structure overlay.

Abstract: Disclosed are techniques, apparatus, and targets for determining overlay error between two layers of a sample. Target A is designed to have an offset Xa between its first and second structures portions; target B is designed to have an offset Xb; target C is designed to have an offset Xc; and target D is designed to have an offset Xd. Each of the offsets Xa, Xb, Xc and Xd is preferably different from zero; Xa is an opposite sign and differ from Xb; and Xc is an opposite sign and differs from Xd. The targets A, B, C and D are illuminated with electromagnetic radiation to obtain spectra SA, SB, SC, and SD from targets A, B, C, and D, respectively. Any overlay error between the first structures and the second structures is then determined using a linear approximation based on the obtained spectra SA, SB, SC, and SD.

Abstract: Disclosed are techniques and apparatus are provided for determining overlay error or pattern placement error (PPE) across the field of a scanner which is used to pattern a sample, such as a semiconductor wafer or device. This determination is performed in-line on the product wafer or device. That is, the targets on which overlay or PPE measurements are performed are provided on the product wafer or device itself. The targets are either distributed across the field by placing the targets within the active area or by distributing the targets along the streets (the strips or scribe areas) which are between the dies of a field. The resulting overlay or PPE that is obtained from targets distributed across the field may then be used in a number of ways to improve the fabrication process for producing the sample.

Abstract: A semiconductor wafer may include a dummy field configured to enable overlay measurements. The enhanced dummy field may include a plurality of encoding blocs that enable OVL measurements to be made throughout the enhanced dummy field.

Abstract: An overlay mark for determining the relative shift between two or more successive layers of a substrate and methods for using such overlay mark are disclosed. In one embodiment, the overlay mark includes at least one test pattern for determining the relative shift between a first and a second layer of the substrate in a first direction. The test pattern includes a first set of working zones and a second set of working zones. The first set of working zones are disposed on a first layer of the substrate and have at least two working zones diagonally opposed and spatially offset relative to one another. The second set of working zones are disposed on a second layer of the substrate and have at least two working zones diagonally opposed and spatially offset relative to one another. The first set of working zones are generally angled relative to the second set of working zones thus forming an “X” shaped test pattern.

Abstract: Disclosed are techniques and apparatus are provided for determining overlay error or pattern placement error (PPE) across the field of a scanner which is used to pattern a sample, such as a semiconductor wafer or device. This determination is performed in-line on the product wafer or device. That is, the targets on which overlay or PPE measurements are performed are provided on the product wafer or device itself. The targets are either distributed across the field by placing the targets within the active area or by distributing the targets along the streets (the strips or scribe areas) which are between the dies of a field. The resulting overlay or PPE that is obtained from targets distributed across the field may then be used in a number of ways to improve the fabrication process for producing the sample.

Abstract: Disclosed are overlay targets having flexible symmetry characteristics and metrology techniques for measuring the overlay error between two or more successive layers of such targets. In one embodiment, a target includes structures for measuring overlay error (or a shift) in both the x and y direction, wherein the x structures have a different center of symmetry (COS) than the y structures. In another embodiment, one of the x and y structures is invariant with a 180° rotation and the other one of the x and y structures has a mirror symmetry. In one aspect, the x and y structures together are variant with a 180° rotation. In yet another example, a target for measuring overlay in the x and/or y direction includes structures on a first layer having a 180 symmetry and structures on a second layer having mirror symmetry.

Abstract: Disclosed are apparatus and methods for monitoring a characteristic associated with a product feature on a semiconductor product. A proxy target formed from at least one substructure that corresponds to a product feature is provided. The substructure is not individually resolvable by an optical tool. A characteristic of the proxy target is determined based on optically monitoring the proxy target using the optical tool. Based on the determined characteristic of the proxy target, it is then determined whether the corresponding product feature has a characteristic that is within a predetermined specification or whether a process parameter used to fabricate such product feature is within a predetermined specification. In a specific embodiment, the characteristic of the corresponding product feature includes a shape parameter and a position parameter.

Abstract: Disclosed are overlay targets having flexible symmetry characteristics and metrology techniques for measuring the overlay error between two or more successive layers of such targets. In one embodiment, a target includes structures for measuring overlay error (or a shift) in both the x and y direction, wherein the x structures have a different center of symmetry (COS) than the y structures. In another embodiment, one of the x and y structures is invariant with a 180° rotation and the other one of the x and y structures has a mirror symmetry. In one aspect, the x and y structures together are variant with a 180° rotation. In yet another example, a target for measuring overlay in the x and/or y direction includes structures on a first layer having a 180 symmetry and structures on a second layer having mirror symmetry.

Abstract: Disclosed are overlay targets having flexible symmetry characteristics and metrology techniques for measuring the overlay error between two or more successive layers of such targets. In one embodiment, a target includes structures for measuring overlay error (or a shift) in both the x and y direction, wherein the x structures have a different center of symmetry (COS) than the y structures. In another embodiment, one of the x and y structures is invariant with a 180° rotation and the other one of the x and y structures has a mirror symmetry. In one aspect, the x and y structures together are variant with a 180° rotation. In yet another example, a target for measuring overlay in the x and/or y direction includes structures on a first layer having a 180 symmetry and structures on a second layer having mirror symmetry.