Carbon contamination of EUV mask and its effect on CD performance

Lee, Sangsul; Doh, Jong Gul; Lee, Jae Uk; Lee, Inhwan; Jeong, Chul; Lee, Dong Gun; Rah, Seungyu; Ahn, Jinho

doi:10.1016/j.cap.2011.07.019

Cited by 10 publications

(4 citation statements)

References 9 publications

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“…We have already reported quantitative analysis of the phase shift effect of EUV phase shift mask using single-shot CDI engines, such as error reduction algorithm (ERA) and hybrid input-output (HIO) algorithm. [13][14][15][16][17] However, in the case of single-shot CDI, the field-of-view is limited by the size of the inspection beam at the mask plane (3 μm diameter). Also, the information of light source and object cannot be deconvolved, and this makes an accurate analysis of the object difficult.…”

Section: Introductionmentioning

confidence: 99%

Through-pellicle imaging of extreme ultraviolet mask with extreme ultraviolet ptychography microscope

Woo

Kim

Jang

et al. 2019

J. Micro/Nanolith. MEMS MOEMS

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Background: An extreme ultraviolet (EUV) pellicle is necessary to increase the process yield even though the declining throughput is a big concern. However, an EUV metrology/inspection tool for this pellicle has not been commercialized yet. Aim: The goal of this study is to verify the pellicle/mask inspection feasibility of EUV scanning lensless imaging (ESLI) and verify the impact of contaminants on pellicles depending on their size. Approach: Through-pellicle imaging was implemented by using ESLI, which uses a high-order harmonic generation EUV source and ptychography. Optical characteristics of various sizes of Fe-contaminated EUV pellicles were evaluated to verify their impact on wafer images. Results: Large size (∼10 μm) contaminants on the pellicle were found to contribute to the final wafer pattern loss. However, small size (2 to 3 μm) contaminants on the pellicle do not have substantial impact on the wafer image. Conclusions: The defect detection capability of ESLI for pellicle and mask was confirmed. Therefore, ESLI is useful in applications like pellicle qualification and EUV mask inspection metrology.

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Section: Introductionmentioning

confidence: 99%

Through-pellicle imaging of extreme ultraviolet mask with extreme ultraviolet ptychography microscope

Woo

Kim

Jang

et al. 2019

J. Micro/Nanolith. MEMS MOEMS

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“…The formation of residual carbon contamination on the EUV system such as masks and optics is a serious challenge for the high-volume manufacturing of EUV exposure tools. It is known to reduce the reflectivity of the EUV mask, thereby causing a problem of pattern size increases during pattering (1)(2)(3).…”

Section: Introductionmentioning

confidence: 99%

A Novel Cleaning Approach to Remove the Carbon Contaminant from Ru Surface of EUV Mask

Kim¹,

Song²,

Kim³

et al. 2017

ECS Trans.

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“…The EUV group at the New Subaru, Japan, is developing a CDI-based EUV mask inspection tool [8]. In Hanyang University, a stand-alone tool based on CDI method [9] for CD analysis of patterned masks. These aforementioned CDI methods are only limited to periodic patterns, unlike scanning CDI methods, such as ptychography, which can reconstruct arbitrary patterns.…”

Section: Introductionmentioning

confidence: 99%

Scanning coherent scattering methods for actinic EUV mask inspection

et al. 2016

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Actinic mask inspection for EUV lithography with targeted specifications of resolution, sensitivity, and throughput remains a big hurdle for the successful insertion of EUVL into high volume manufacturing and effective solutions are needed to address this. We present a method for actinic mask inspection based on scanning coherent scattering microscopy. In this method, the mask is scanned with an EUV beam of relatively small spot size and the scattered light is recorded with a pixel detector. Customized algorithms reconstruct the aerial image by iteratively solving the phaseproblem using over-determined diffraction data gathered by scanning across the specimen with a finite illumination. This approach provides both phase and amplitude of actinic aerial images of the mask with high resolution without the need to use high NA (numerical aperture) lenses. Futher, we describe a reflective mode EUV mask scanning lensless imaging tool (RESCAN), which was installed at the XIL-II beamline and later at the SIM beamline of the Swiss Light Source and show reconstructed aerial images down to 10 nm (on-wafer) resolution. As a complementary method, the a-priori knowledge of the sample is employed to identify potential defect sites by analyzing the diffraction patterns. In this method, the recorded diffraction patterns are compared with the die or database data (i.e. previously measured or calculated diffraction data from the defect-free mask layout respectively) and their difference is interpreted as the defect signal. Dynamic software filtering helps to suppress the strong diffraction from defect-free structures and allows registration of faint defects with high sensitivity. Here, we discuss the basic principles of these Fourier domain techniques and its potential for actinic mask inspection with high signal-to-noise ratio and high throughput.

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Carbon contamination of EUV mask and its effect on CD performance

Cited by 10 publications

References 9 publications

Through-pellicle imaging of extreme ultraviolet mask with extreme ultraviolet ptychography microscope

Through-pellicle imaging of extreme ultraviolet mask with extreme ultraviolet ptychography microscope

A Novel Cleaning Approach to Remove the Carbon Contaminant from Ru Surface of EUV Mask

Scanning coherent scattering methods for actinic EUV mask inspection

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