Abstract:
An overlay metrology system may measure a first-layer pattern placement distance between a pattern of device features and a pattern of reference features on a first layer of an overlay target on a sample. The system may further measure, subsequent to fabricating a second layer including at least the pattern of device features and the pattern of reference features, a second-layer pattern placement distance between the pattern of device features and the pattern of reference features on the second layer. The system may further measure a reference overlay based on relative positions of the pattern of reference features on the first layer and the second layer. The system may further determine a device-relevant overlay for the pattern of device-scale features by adjusting the reference overlay with a difference between the first-layer pattern placement distance and the second-layer pattern placement distance.
Abstract:
An overlay metrology system may include a controller to generate optical tool error adjustments for a hybrid overlay target including optically-resolvable features and device-scale features by measuring a difference between an optical overlay measurement based on the optically-resolvable features and a device-scale overlay measurement based on the device-scale features, generate target-to-device adjustments for the hybrid overlay target based on positions of features within the device area, determine device-relevant overlay measurements for one or more locations in the device area based on at least one of the optical overlay measurement, the optical tool error adjustments, or the target-to-device adjustments, and provide overlay correctables for the device area to a lithography tool to modify exposure conditions for at least one subsequent exposure based on the device-relevant overlay measurements.
Abstract:
In a method for controlling the positioning of patterns on a substrate in a manufacturing process at least one registration measurement is conducted with a registration tool on at least one pattern formed in at least one layer on the substrate by a previous process step of the manufacturing process. From the registration measurement a position of the at least one pattern in a coordinate system is determined. The determined position of the at least one pattern is fed into an automatic process control of a manufacturing system for controlling a setup of the manufacturing system for a subsequent process step of the manufacturing process. The manufacturing process may be a wafer manufacturing process with a silicon substrate. Complementary information may be collected in addition to performing the registration measurement and fed to the automatic process control. The process steps may for example include lithography steps, etching steps, layer deposition.
Abstract:
A method is disclosed for correcting errors introduced by optical distortions or aberrations in the measured values of coordinates of targets of an array of targets, like for example structures on a wafer or a photolithography mask. The array of targets is placed into a field of view of an imaging system via which the coordinates are to be measured. The array of targets is placed at different relative positions with respect to the field of view, and for each relative position the coordinates of the targets relative to the array of targets are determined by measurements. From the results of these measurements an alignment function, giving a correction for optical errors as a function of the position in the field of view, is derived. The measured coordinates are corrected by the alignment function. The corrected coordinates can be used to identify registration errors of a mask writer.
Abstract:
Methods and systems for performing measurements of multiple die with an array of electron beam columns are presented herein. The wafer is scanned in a direction parallel to the die rows disposed on the wafer. The electron beam measurement columns are spatially separated in a column alignment direction. The wafer is scanned in a direction that is oriented at an oblique angle with respect to the column alignment direction such that each electron beam column measures the same row of die features on different die during the same wafer pass. The wafer is oriented with respect to the array of electron beam columns by rotating the wafer, rotating the electron beam columns, or both. In further aspects, each measurement beam is deflected to correct alignment errors between each column and the corresponding die row to be measured and to correct wafer positioning errors reported by the wafer positioning system.
Abstract:
An apparatus and a method are disclosed for the measurement of pattern placement and/or edge placement and/or size of a pattern on a surface of a substrate for the semiconductor industry. At least one source for detection and at least one assigned detector are used to measure the positions of a pattern on a substrate. With a movable stage the substrate is moved while detection takes place. A displacement measurement system determines the position of the movable stage during the movement. A computer is used for correlating detected signals of the at least one detector along the derived trace line with the actual positions of the stage during the movement of the stage.
Abstract:
A method for correcting optical errors occurring in coordinates of positions of a plurality of targets measured via an imaging system comprising a field of view. The plurality of targets includes a first array of targets and a second array of targets overlapping the first array of targets, and a portion of the plurality of targets are outside of the field of view. The method broadly includes the following steps: a) placing the first array of targets in the field of view of the imaging system; b) measuring coordinates of each target within the first array of targets repeatedly via the imaging system; c) placing the second array of targets in the field of view of the imaging system; d) measuring coordinates of each target within the second array of targets repeatedly via the imaging system; e) determining an alignment function from the measurement results of step b, step d, or steps b and d, the alignment function being a function of coordinates of the field of view of the imaging system and giving an additive correction for optical errors of the coordinates of positions of the plurality of targets measured by the imaging system; f) correcting the coordinates of the positions of the plurality of targets measured by the imaging system by adding the respective value of the alignment function at the field-of-view coordinates at which the coordinates of the position of the respective target were measured; and, g) obtaining a final result for the position of each target of the plurality of targets by averaging over the corrected coordinates found in step f for the respective target at each relative position of the plurality of targets and field of view of the imaging system.
Abstract:
A method for correcting optical errors occurring in coordinates of positions of a plurality of targets measured via an imaging system comprising a field of view. The plurality of targets includes a first array of targets and a second array of targets overlapping the first array of targets, and a portion of the plurality of targets are outside of the field of view. The method broadly includes the following steps: a) placing the first array of targets in the field of view of the imaging system; b) measuring coordinates of each target within the first array of targets repeatedly via the imaging system; c) placing the second array of targets in the field of view of the imaging system; d) measuring coordinates of each target within the second array of targets repeatedly via the imaging system; e) determining an alignment function from the measurement results of step b, step d, or steps b and d, the alignment function being a function of coordinates of the field of view of the imaging system and giving an additive correction for optical errors of the coordinates of positions of the plurality of targets measured by the imaging system; f) correcting the coordinates of the positions of the plurality of targets measured by the imaging system by adding the respective value of the alignment function at the field-of-view coordinates at which the coordinates of the position of the respective target were measured; and, g) obtaining a final result for the position of each target of the plurality of targets by averaging over the corrected coordinates found in step f for the respective target at each relative position of the plurality of targets and field of view of the imaging system.
Abstract:
An overlay metrology system may include a controller to generate optical tool error adjustments for a hybrid overlay target including optically-resolvable features and device-scale features by measuring a difference between an optical overlay measurement based on the optically-resolvable features and a device-scale overlay measurement based on the device-scale features, generate target-to-device adjustments for the hybrid overlay target based on positions of features within the device area, determine device-relevant overlay measurements for one or more locations in the device area based on at least one of the optical overlay measurement, the optical tool error adjustments, or the target-to-device adjustments, and provide overlay correctables for the device area to a lithography tool to modify exposure conditions for at least one subsequent exposure based on the device-relevant overlay measurements.
Abstract:
An apparatus and a method are disclosed for the measurement of pattern placement and/or edge placement and/or size of a pattern on a surface of a substrate for the semiconductor industry. At least one source for detection and at least one assigned detector are used to measure the positions of a pattern on a substrate. With a movable stage the substrate is moved while detection takes place. A displacement measurement system determines the position of the movable stage during the movement. A computer is used for correlating detected signals of the at least one detector along the derived trace line with the actual positions of the stage during the movement of the stage.