摘要:
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.
摘要:
Disclosed are apparatus and methods for obtaining and analyzing various unique metrics or “target diagnostics” from one or more semiconductor overlay targets. In one embodiment, an overlay target is measured to obtain one or both of two specific types of target diagnostic information, systematic error metrics and/or random noise metrics. The systematic error metrics generally quantify asymmetries of the overlay target, while the random noise metrics quantify and/or qualify the spatial noise that is proximate to or associated with the overlay target.
摘要:
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. It is determined whether there are any overlay error between the first structures and the second structures using a scatterometry technique based on the detected spectra by (i) for each target, determining a first differential intensity between the −1st diffraction order and a +1st diffraction order, (ii) for a plurality of pairs of targets each having a first target and a second target, determining a second differential intensity between the first differential intensity of the first target and the first differential intensity of the second target, and (iii) determining any overlay error between the first structures and the second structures using a scatterometry technique based on the second differential intensities determined from each target pair.
摘要:
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. It is determined whether there are any overlay error between the first structures and the second structures using a scatterometry technique based on the detected spectra by (i) for each target, determining a first differential intensity between the −1st diffraction order and a +1st diffraction order, (ii) for a plurality of pairs of targets each having a first target and a second target, determining a second differential intensity between the first differential intensity of the first target and the first differential intensity of the second target, and (iii) determining any overlay error between the first structures and the second structures using a scatterometry technique based on the second differential intensities determined from each target pair.
摘要:
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.
摘要:
Methods and apparatus for producing a semiconductor. A production reticle having a pattern that includes circuit features, phase shift target structures and overlay target structures is provided. The pattern is transferred multiple times across a test wafer surface for various focus levels to form a focus matrix. The pattern shift of the phase shift target structures is measured using an overlay metrology tool. The phase difference is calculated for each phase shift target structure, based on the pattern shift and the phase shift target structure focus level to qualify the phase difference of the production reticle. The pattern is transferred onto a production wafer when the phase difference meets desired limits. The pattern shift of the overlay target structures transferred to the production wafer is measured using an overlay metrology tool. The pattern placement error of the overlay target structures is calculated and the pattern placement error is qualified.
摘要:
A method of inspecting a phase shift mask is disclosed. The method includes receiving a mask having an alternating phase shift pattern. The method also includes forming the alternating phase shift pattern on a wafer. The method further includes analyzing the alternating phase shift pattern on the wafer to determine the phase difference of the alternating phase shift pattern.
摘要:
Disclosed are apparatus and methods for obtaining and analyzing various unique metrics or “target diagnostics” from one or more semiconductor overlay targets. In one embodiment, an overlay target is measured to obtain one or both of two specific types of target diagnostic information, systematic error metrics and/or random noise metrics. The systematic error metrics generally quantify asymmetries of the overlay target, while the random noise metrics quantify and/or qualify the spatial noise that is proximate to or associated with the overlay target.
摘要:
Disclosed are methods and apparatus for analyzing the quality of overlay targets. In one embodiment, a method of extracting data from an overlay target is disclosed. Initially, image information or one or more intensity signals of the overlay target are provided. An overlay error is obtained from the overlay target by analyzing the image information or the intensity signal(s) of the overlay target. A systematic error metric is also obtained from the overlay target by analyzing the image information or the intensity signal(s) of the overlay target. For example, the systematic error may indicate an asymmetry metric for one or more portions of the overlay target. A noise metric is further obtained from the overlay target by applying a statistical model to the image information or the intensity signal(s) of the overlay target. Noise metric characterizes noise, such as a grainy background, associated with the overlay target. In other embodiments, an overlay and/or stepper analysis procedure is then performed based on the systematic error metric and/or the noise metric, as well as the overlay data.
摘要:
Disclosed are methods and apparatus for analyzing the quality of overlay targets. In one embodiment, a method of extracting data from an overlay target is disclosed. Initially, image information or one or more intensity signals of the overlay target are provided. An overlay error is obtained from the overlay target by analyzing the image information or the intensity signal(s) of the overlay target. A systematic error metric is also obtained from the overlay target by analyzing the image information or the intensity signal(s) of the overlay target. For example, the systematic error may indicate an asymmetry metric for one or more portions of the overlay target. A noise metric is further obtained from the overlay target by applying a statistical model to the image information or the intensity signal(s) of the overlay target. Noise metric characterizes noise, such as a grainy background, associated with the overlay target. In other embodiments, an overlay and/or stepper analysis procedure is then performed based on the systematic error metric and/or the noise metric, as well as the overlay data.