| Zugriffsnummer | 10359 |
| Dokumenttyp | Konferenzartikel in Zeitschrift |
| Sprache | Englisch |
| Titel | Characterization of EUV masks by EUV-scatterometry [poster] |
| Autor(in); Institution |
Perlich, J.; Infineon Technologies, Munich/Dresden, GERMANY
Kamm, F.-M.; Infineon Technologies, Munich/Dresden, GERMANY
Rau, J.; Infineon Technologies, Munich/Dresden, GERMANY
Scholze, Frank; 7.12, Röntgenradiometrie, PTB-Berlin
Ulm, Gerhard; 7.1, Photonenradiometrie, PTB-Berlin
|
| Quelle/Jahr | Papers from the 48th International Conference on Electron, Ion, and Photon Beam Technology and Nanofabrication. Journal of Vacuum Science and Technology B: 22 (2004), 6, 3059 - 3062 |
| ISSN | 0734-211X |
| Verlag | New York, NY: AIP |
| Konferenzangaben | EIPBN 2004, San Diego, Calif., 01-04, June, 2004, USA |
| Zusammenfassung | As an alternative to conventional SEM- or AFM-based CD characterization, optical scatterometry is currently widely investigated and applied for wafer- as well as mask CD-metrology. In order to fulfill the measurement resolution requirements for the future technology nodes an extension to shorter measurement wavelengths is desirable. Especially for the EUV technology node, an actinic measurement at EUV wavelengths could provide additional information, such as local EUV-reflectance in patterned areas, which might not be accessible with other methods. For the reason, EUV scatterometry for mask CD-metrology has been investigated at the BESSY II storage ring. The measurement wavelength is 13.35 nm with an incident angle of 5° with respect to the surface normal. The non-specular diffraction signal has been measured up to an angle of 2Θ/2 = 10°. The measured pattern consists of periodic lines and spaces structures with a nominal critical dimension (CD) of 400 nm on mask level at a pitch of 800 nm. As an absorber material, Cr with a thickness of 70 nm has been used while the buffer layer consists of SiO2 with 60 nm thickness. The multilayers consist of 40 bi-layers of Mo/Si with a central wavelength of 13.5 nm. The measured signal is compared to theoretical models as well as numerical calculation. A comparison to the conventional diffraction theory for infinitely thin masks clearly shows deviations due to topographical effects, as can be expected. A more sophisticated model approach, taking into account geometrical shadowing effects already shows better agreement. The best agreement is achieved with numerical calculations of the diffraction pattern using waveguide methods. A best first CD-SEM value as well as buffer- and absorber sidewall angles is performed. The χ2-curve as a function of sidewall angles is observed to be quite flat near the optimum fit value, indicating a small sensitivity on sidewall angle. |
