Characterization of Overlay and Tilt in Advanced Technology Nodes using Scatterometry

Dixit, Dhairya; Dey, Sonal; Kagalwala, Taher; Timoney, Padraig; Ramnath, Yudesh; Elia, Alexander; Paranjape, Ninad; Keller, Nick; Vaid, Alok

doi:10.1109/asmc.2019.8791810

Cited by 5 publications

(11 citation statements)

References 4 publications

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“…On the other hand, 3  3 MM components includes not only linear response of the polarization and phase but nonlinear birefringent behaviors in off-diagonal components, which can be explained by the anisotropic characteristic of the 3D structures [9]. The slight improvement of MM model (R2 scores of 0.97 and 0.96) with respect to the result of Ψ and Δ indicates that the 3D structure we measured less contains anisotropic features such as overlay error [10].…”

Section: Principle Of Imaging-based Massive Mmsementioning

confidence: 82%

Wide-field massive CD metrology based on the imaging Mueller-matrix ellipsometry for semiconductor devices

Son

Hwang

et al. 2023

Metrology, Inspection, and Process Control XXXVII

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In this paper, we propose an unique metrology technique for the measurement of three-dimensional (3D) nanoscale structures of semiconductor devices, employing imaging-based massive Mueller-matrix spectroscopic ellipsometry (MMSE) with ultra-wide field of view (FOV) of 20×20 mm2. The proposed system enables rapid measurement of 10 million critical dimension (CD) values from all pixels in the image, while the conventional point-based metrology technique only measures a single CD value. We obtain Mueller matrix (MM) spectrum by manipulating wavelength and polarization states using a custom designed optical setup, and show that the proposed method characterizes complex 3D structures of the semiconductor device. We experimentally demonstrate CD measurement performance and consistency in the extremely large FOV, and suggest that the combination of MMSE and massive measurement capability can provide valuable insights: fingerprints originated from the manufacturing process, which are not easily obtained with conventional techniques.

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Section: Principle Of Imaging-based Massive Mmsementioning

confidence: 82%

Wide-field massive CD metrology based on the imaging Mueller-matrix ellipsometry for semiconductor devices

Son

Hwang

et al. 2023

Metrology, Inspection, and Process Control XXXVII

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“…1 However, the dimension of the defects that may occur in the structures does not change, so their effect becomes increasingly significant. 2 The non-uniformities can reduce the performance of the device; the leakage current may increase, and it also affects the CMOS threshold voltage. 2,3 For these transistors to work as efficiently as possible, it is particularly important to monitor the complex, multi-step processes, and reveal the possible imperfections.…”

Section: Introductionmentioning

confidence: 99%

“…2 The non-uniformities can reduce the performance of the device; the leakage current may increase, and it also affects the CMOS threshold voltage. 2,3 For these transistors to work as efficiently as possible, it is particularly important to monitor the complex, multi-step processes, and reveal the possible imperfections. With the appearance of new devices, new types of defects also arise, which require new metrological solutions.…”

Section: Introductionmentioning

confidence: 99%

“…The modified process steps used in the case of front end of line (FEOL) forksheet FET manufacturing, may result in new types of defects instead of or in addition to the typical ones present in previous structures (e.g., pitch-walking, overlay-error, fin-bending, line width roughness, line edge roughness, etc. 2,4 ). During the lithography process, the structure may bend or/and the length of the nanosheets may differ on opposite sides of the wall.…”

Section: Introductionmentioning

confidence: 99%

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Detection of structural asymmetries in Forksheet FET arrays using Mueller matrix ellipsometry: a theoretical study

Dikó,

Kiss,

Egri

et al. 2024

J. Micro/Nanopattern. Mats. Metro.

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Background: With the appearance of ever-smaller transistors and new structures, new metrological challenges also arise, including the detection of different structural defects. Mueller matrix (MM) measurement can provide an opportunity to investigate them.Aim: Defects can cause a deterioration in device performance; therefore, their characterization is particularly important. Our goal is to investigate the possibility of detecting asymmetry defects using MM measurement and to study the distinguishability of these structural imperfections in the case of forksheet field-effect transistor (FET).Approach: Simulation of MM measurements with different degrees and directions of forksheet FET's profile asymmetries. To quantify the distinguishability of the optical responses caused by the defects, the correlation between the asymmetry parameters was calculated. Since the precise alignment of a sample is a key factor in the detection of asymmetries, the effect of the alignment uncertainty and a method for filtering it out were also investigated.Results and Conclusions: MM measurement is sensitive to both the magnitude and direction of the profile bending and the shift of the dielectric wall. The correlation coefficients show that the optical responses of the asymmetry defects and the alignment error can be distinguished. The latter can even be eliminated with a method presented in this article.

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“…Conventional overlay metrology encounters limitations in resolution, throughput, and accuracy, leading researchers and engineers to develop new metrology solutions. To address the limitations of conventional overlay metrology, several novel approaches have been proposed, such line-scanning hyper spectral imaging [5], self-interferometric pupil ellipsometry [6] and the use of microsphere for nano-spot spectroscopy [7] One promising technique is Mueller matrix spectroscopic ellipsometry (MMSE) [8], a type of spectroscopic ellipsometry (SE) that measures the Mueller matrix, which contains information about the polarization state changes that occur when light interacts with the sample. MMSE is particularly effective for overlay error metrology because it provides more information including the anisotropy (e.g., circular birefringence and circular dichroism) of the sample.…”

Section: Introductionmentioning

confidence: 99%

Massive overlay metrology solution by realizing imaging Mueller matrix spectroscopic ellipsometry

Son

Hwang

et al. 2023

Metrology, Inspection, and Process Control XXXVII

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In recent years, the overlay specifications of advanced semiconductor devices have become extremely stringent. This challenging situation becomes severe for every new generation of the device development. However, conventional overlay metrology systems have limited throughput due to their point-based nature. Here, we first demonstrate the novel imaging Mueller-matrix spectroscopic ellipsometry (MMSE) technique, which can measure the overlay error of all cell blocks on a device wafer with extremely high throughput, much faster than conventional point-based spectroscopic ellipsometry (SE) technologies. It provides the super large field of view (FOV) ~ 20 × 20 mm2 together with high sensitivity based on Mueller information, which will be truly innovated solution not only for the overlay metrology, but also for critical dimension (CD) measurement, eventually maximizing process control and productivity of advanced node.

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Characterization of Overlay and Tilt in Advanced Technology Nodes using Scatterometry

Cited by 5 publications

References 4 publications

Wide-field massive CD metrology based on the imaging Mueller-matrix ellipsometry for semiconductor devices

Wide-field massive CD metrology based on the imaging Mueller-matrix ellipsometry for semiconductor devices

Detection of structural asymmetries in Forksheet FET arrays using Mueller matrix ellipsometry: a theoretical study

Massive overlay metrology solution by realizing imaging Mueller matrix spectroscopic ellipsometry

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