EUV Mask and Blank Inspection

Two people in cleanroom clothing standing in front of a device that looks like a large metal cabinet.

EUV Solutions

EUV Mask and
Blank Inspection

Two people in cleanroom clothing stand in front of the control panel of a device that looks like a large metal cabinet.

EUV Solutions

EUV Mask and
Blank Solutions

Mask and Blank Solutions

Our reflectometer systems are designed to provide spectral and spatial characterization of multilayers, mask blanks and masks. Full spectral characterization can be combined with high spatial resolution and fixed wavelength, providing effective reflection homogeneity information across the entire blank. For masks, scatterometry can be integrated to probe diffraction efficiency and CD information. Our systems can be designed to handle 12 inch masks and provide valuable information for the development of next technology nodes.

Mask Blank Reflectometer

Actinic Inband Mapping EUV Reflectometry

EUV-MBR

The EUV Mask Blank Reflectometers (EUV MBRs) are stand alone tools for automated qualification of multilayers and absorbers on EUV masks and mask blanks. They are designed for measuring reflectance properties e.g. peak reflectance, central wavelengths, FWHM and side wiggles and their homogeneity and fidelity in contamination free, ultra clean environments. Mask handling is customer specific with semi-manual load lock or with RSP 200 load ports. Faster throughput by storage, magnetically levitated handling or linked to OHT are feasible on demand.

Stand-alone EUV-MBR

With our proprietary triple spectra polychromatic concept spectra reflection curves with 2000 spectral channels of Dl=1.7 pm are measured in parallel in <5s exposure time.

RI "triple spectra polychromatic" concept

EUV-AIMER

RI’s proprietary Actinic Inband Mapping EUV Reflectometry (AIMER™) measures the effective feature of a sample “as seen by the scanner”. In the EUVL scanner, the spectral distribution of the wafer exposure is of about 2 % bandwidth centered on the central wavelength of 13.52 nm. Hence all radiation incident on the mask is contributing to the total dose on the wafer weighted with the effective spectral transfer efficiency P(λ) to the wafer exposures with the integral of P(λ) equaling unity:

For qualifying any spectral dependent property of an element with respect to its performance when used in the scanner, only the relevant contribution weighted by P(λ) is of importance.

E.g. this concept provides can effective reflectance R_effof a mask or mask blank:
The effective reflectance R_eff is sensitive to R_max, CWL_50, FWHM and obtained combined in a simple fast registration instead of extrapolating from spectral reflectance measurement R(λ)^.

AIMER map obtained with test on EUV-MBR provides full mask blank data, which are recorded in less than 30 minutes exposure

The basic distribution can be confirmed by 5x5 site measurements at ALS where the CWL is found as main contributor

Literature on EUV-MBR

R. Lebert et. al., High-throughput EUV reflectometer for EUV mask blanks, Proc. SPIE 5374 (2004)
DOI: 10.1117/12.537012
A. Farahzadi et. al., The task of EUV reflectometry for HVM of EUV masks: first steps, Proc. SPIE 7470 (2009)
DOI: 10.1117/12.835176
H. Seitz et. al., Production challenges of making EUV mask blanks, Proc. SPIE 5835 (16 June 2005)
DOI: 10.1117/12.637335
C. Wies et. al., High speed reflectometer for EUV mask-blanks, Proc. SPIE 5835; 252; (2005)
DOI: 10.1117/12.637341

Literature on EUV-AIMER

A. Biermanns-Föth, C. Phiesel, T. Missalla, J. Arps, C. Piel, and R. Lebert,, Proc. SPIE 10809, International Conference on Extreme Ultraviolet Lithography 2018, 108091I (3 October 2018);
DOI: 10.1117/12.2501794
A. Biermanns-Föth, C. Phiesel, T. Missalla, J. Arps, C. Piel, and R. Lebert,, Proc. SPIE 10957, Extreme Ultraviolet (EUV) Lithography X, 109571G (26 March 2019);
DOI: 10.1117/12.2515336

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