&lt;title&gt;Self-calibration in two dimensions: the experiment&lt;/title&gt;

Takac, Michael T.; Ye, Jun; Raugh, Michael; Pease, R. F. W.; Berglund, C. N.; Owen, G.

doi:10.1117/12.240149

Cited by 20 publications

(11 citation statements)

References 2 publications

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“…For high precision 2D stage calibration different self-calibration approaches were published, which all allow to determine the deviations of a 2D grid pattern from a nominal 2D grid [16,17]. This is accomplished by repeated measurements of the mask in at least two different orientations and in at least one shifted grid raster position of the mask.…”

Section: 5d Reference Metrology For Mask Registration Measurementsmentioning

confidence: 99%

Development of a 1.5D reference comparator for position and straightness metrology on photomasks

Flügge

Köning

Weichert

et al. 2008

Photomask Technology 2008

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The so-called Nanometer Comparator is the PTB vacuum length comparator which has been developed for high precision length metrology on measurement objects with micro-and nanostructured graduations, like e.g. line scales, incremental encoders or photomasks. The Nanometer Comparator allows to achieve smallest measurement uncertainties in the nm-range by use of vacuum laser interferometry for the displacement measurement. We will report on the achieved measurement performance of this high precision vacuum length comparator and the already started developments to substantially enhance its measurement capabilities by additional straightness measurement capabilities. The enhanced Nanometer Comparator will provide traceability for photomask pattern placement measurements in industry, also facing the challenges due to the increased requirements on registration metrology as set by the introduction of new lithography techniques like double patterning methods.

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Section: 5d Reference Metrology For Mask Registration Measurementsmentioning

confidence: 99%

Development of a 1.5D reference comparator for position and straightness metrology on photomasks

Flügge

Köning

Weichert

et al. 2008

Photomask Technology 2008

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“…Usually, the calculation of the stage error needs calibration technology [7], [8] with a standard measurement scale. Once the stage error is exactly known, the measurement compensation of the positioning accuracy and repeatability of precision motion systems will become more accurate [9], [10]. However, for precision/ultraprecision applications such as nanolithography, there usually not exists a standard measurement scale with better accuracy of mark positions than the metrology system.…”

Section: Introductionmentioning

confidence: 99%

“…However, the algorithm is likely to be computationally expensive and may be unstable in the presence of random measurement noise. Takac [9] proposed a transitive algorithm based on direct pointto-point comparison for the 2-D self-calibration. This direct transitive algorithm is intuitive and simple but is extremely sensitive to random measurement noise due to its oversimplified handling of the rotation and translation of each measurement view.…”

Section: Introductionmentioning

confidence: 99%

A Holistic Self-Calibration Algorithm for $xy$ Precision Metrology Systems

Zhu

et al. 2012

IEEE Trans. Instrum. Meas.

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Self-calibration technology is an important approach with the utilization of an artifact plate with mark positions that are not precisely known to calibrate the precision metrology system. In this paper, we study the self-calibration of xy precision metrology systems and present a holistic self-calibration algorithm based on the least squares method. The proposed strategy utilizes three traditional measurement views of an artifact plate on the xy metrology stage and provides relevant symmetry, transitivity, and redundancy. The misalignment errors of all measurement views, particularly errors of the translation view, are totally determined by detailed mathematical manipulations. Consequently, a leastsquares-based robust estimation law is synthesized to calculate the stage error even under the existence of random measurement noise. Computer simulation validates that the proposed method can accurately realize the stage error when there is no random measurement noise. Furthermore, the calculation accuracy of the proposed scheme under various random measurement noises is studied, and the results verify that the proposed algorithm can effectively attenuate the effects of random measurement noise. The proposed strategy, in fact, provides a well-understood solution to the xy self-calibration problem for engineers in practical applications.Index Terms-Least squares, measurement noise, selfcalibration, stage error, xy metrology system.

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“…Due to the difficulty on finding a more accurate standard tool in traditional calibration technologies, self-calibration technology has been developed with utilization of an artifact with mark positions not precisely known. As an alternative of intelligent calibration processes, self-calibration is an effective and economical approach especially for micro-/nano-level mechanical systems [11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Self-Calibration of Precision XYθ_z Metrology Stages

Hu¹,

Zhu²,

Liu³

2019

Standards, Methods and Solutions of Metrology

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This chapter studies the on-axis calibration for precision XYθ z metrology stages and presents a holistic XYθ z self-calibration approach. The proposed approach uses an artifact plate, specially designed with XY grid mark lines and angular mark lines, as a tool to be measured by the XYθ z metrology stages. In detail, the artifact plate is placed on the uncalibrated XYθ z metrology stages in four measurement postures or views. Then, the measurement error can be modeled as the construction of XYθ z systematic measurement error (i.e. stage error), artifact error, misalignment error, and random measurement noise. With a new property proposed, redundance of the XYθ z stage error is obtained, while the misalignment errors of all measurement views are determined by rigid mathematical processing. Resultantly, a least squarebased XYθ z self-calibration law is synthesized for final determination of the stage error. Computer simulation is conducted, and the calculation results validate that the proposed scheme can accurately realize the stage error even under the existence of various random measurement noise. Finally, the designed artifact plate is developed and illustrated for explanation of a standard XYθ z self-calibration procedure to meet practical industrial requirements.

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<title>Self-calibration in two dimensions: the experiment</title>

Cited by 20 publications

References 2 publications

Development of a 1.5D reference comparator for position and straightness metrology on photomasks

Development of a 1.5D reference comparator for position and straightness metrology on photomasks

A Holistic Self-Calibration Algorithm for $xy$ Precision Metrology Systems

Self-Calibration of Precision XYθ_z Metrology Stages

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<title>Self-calibration in two dimensions: the experiment</title>

Cited by 20 publications

References 2 publications

Development of a 1.5D reference comparator for position and straightness metrology on photomasks

Development of a 1.5D reference comparator for position and straightness metrology on photomasks

A Holistic Self-Calibration Algorithm for $xy$ Precision Metrology Systems

Self-Calibration of Precision XYθz Metrology Stages

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Product

Resources

About

Self-Calibration of Precision XYθ_z Metrology Stages