CEAS Space Journal

, Volume 9, Issue 4, pp 433–440 | Cite as

Fused silica GRISMs manufactured by hydrophilic direct bonding at moderate heating

  • G. KalkowskiEmail author
  • K. Grabowski
  • G. Harnisch
  • T. Flügel-Paul
  • U. Zeitner
  • S. Risse
Original Paper


For high-resolution spectroscopy in space, GRISM elements—obtained by patterning gratings onto a prism surface—find increasing applications. We report on GRISM manufacturing by joining the individual functional elements—prisms and gratings—to suitable components by the technology of hydrophilic direct bonding. Fused silica was used as a substrate material and binary gratings were fabricated by standard e-beam lithography and dry etching. Alignment of the grating dispersion direction to the prism angle was realized by passive adjustment on dedicated bonding gear matched to the substrate geometry. Materials adapted bonds of high transmission, stiffness, and strength were obtained after heat treatment at temperatures of about 200 °C in vacuum. Examples for bonding uncoated as well as coated grating surfaces are given. The results illustrate the great potential of hydrophilic glass direct bonding for manufacturing transmission optics to be used in space or other heavy duty applications.


GRISM manufacturing Direct bonding Fused silica Binary grating 



We gratefully acknowledge valuable assistance in sample preparation and characterization by K. Jorke, K. Kleinbauer, N. Heidler, G. Leibeling, T. Benkenstein and A. Gottwald, as well as generous support by R. Eberhardt and A. Tünnermann. Part of this work was sponsored by BMWI/DLR under contract no. 55EE1204 and ESA Contract No. 4000114780/15/NL/KML. We appreciate fruitful discussions with P. Bartsch, R. Greinacher, M. Erdmann, B. Harnisch, and B. Guldimann in this context.


  1. 1.
    Haisma, J., Spierings, B., Biermann, U., van Gorkum, A.: Diversity and feasibility of direct bonding: a survey of a dedicated optical technology. Applied Optics 33(7), 1154–1169 (1994)CrossRefGoogle Scholar
  2. 2.
    Tong, Q.-Y., Gösele, U.: Semiconductor wafer bonding. Wiley, New York (1999)Google Scholar
  3. 3.
    Kalkowski, G., Risse, S., Zeitner, U., Fuchs, F., Eberhardt, R., Tünnermann, A.: Glass–glass direct bonding. ECS Transactions 64(5), 3–11 (2014)CrossRefGoogle Scholar
  4. 4.
    Rothhardt, C., Rekas, M., Kalkowski, G., Haarlammert, N., Eberhardt, R., Tünnermann, A.: Fabrication of a high power Faraday isolator by direct bonding. Proc SPIE 8601, 86010T-1 (2013)CrossRefGoogle Scholar
  5. 5.
    Zhang, X.X., Raskin, J.P.: Low-temperature wafer bonding: a study of void formation and influence on bonding strength. J Microelectromechan Syst 14(2), 368–382 (2005)CrossRefGoogle Scholar
  6. 6.
    Kalkowski, G., Zeitner, U., Benkenstein, T., Fuchs, J., Rothhardt, C., Eberhardt, R.: Direct wafer bonding for encapsulation of fused silica optical gratings. Microelectron Eng 97, 177–180 (2012)CrossRefGoogle Scholar
  7. 7.
    Vallin, Ö., Jonsson, K., Lindberg, U.: Adhesion quantification methods for wafer bonding. Mat Sci Eng R 50, 109–165 (2005)CrossRefGoogle Scholar
  8. 8.
    Kalkowski, G., Harnisch, G., Grabowski, K., Benkenstein, T., Ehrhardt, S., Zeitner, U., Risse, S.: Low temperature GRISM direct bonding. Proc SPIE 9574, 95740K–1 (2015)CrossRefGoogle Scholar

Copyright information

© CEAS 2017

Authors and Affiliations

  1. 1.Fraunhofer Institut für Angewandte Optik und FeinmechanikJenaGermany

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