Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-12-01T03:06:00.687Z Has data issue: false hasContentIssue false

Nanoindentation probing of high-aspect ratio pillar structures on optical multilayer dielectric diffraction gratings

Published online by Cambridge University Press:  02 August 2012

K. Mehrotra*
Affiliation:
Department of Mechanical Engineering Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14627
H.P. Howard
Affiliation:
Materials Science Program and Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14627
S.D. Jacobs
Affiliation:
Materials Science Program and Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14627
J.C. Lambropoulos
Affiliation:
Department of Mechanical Engineering Materials Science Program and Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14627
*
aElectronic mail: [email protected]
Get access

Abstract

We measure the mechanical response of optical multilayer dielectric (MLD) diffraction gratings, geometries which are constrained in only one transverse direction but free in the other, using nanoindentation. The results are explained using a stress-strain model, which reveals a uniaxial yield stress of 4.1- 4.6 GPa and predicts a similar dependence of yield stress on loads for both fully-elastic and fully-plastic solutions. Following R. Hill’s model of an expanding cavity under internal pressure, we show that the indentation response of the high-aspect ratio “pillar” geometry can be expressed in terms of uniaxial yield stress rather than material hardness.

Type
Articles
Copyright
Copyright © Materials Research Society 2012

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Strickland, D., et al. ., “Compression of amplified chirped optical pulses”, Optics Comm. 56, 219 (1985).10.1016/0030-4018(85)90120-8Google Scholar
2. Oliver, J. B., et al. ., “Thin-film design for multilayer diffraction gratings”, Proc. of SPIE 5991, 5911 A (2005).Google Scholar
3. Schattenburg, M.L., et al. ., “Advanced interference lithography for nanomanufacturing”, International Society for Nanomanufacturing (ISNM) (2006).Google Scholar
4. Smith, D.J., et al. ., “Large area pulse compression gratings fabricated onto fused silica using scanning beam interference lithography”, ICUIL (2008).Google Scholar
5. Ashe, B., et al. ., “Optimizing a cleaning process for multilayer-dielectric (MLD) diffraction gratings”, LLE Review 112, 228 (2007).Google Scholar
6. Mehrotra, K., et al. ., “Nanoindentation of high-aspect ratio pillar structures on optical multilayer dielectric diffraction gratings”, AIP Advances 1, 042179 (2011).10.1063/1.3673070Google Scholar
7. Oliver, W.C., Pharr, G.M., “An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments”, J. Mater. Res. 7, 1564 (1992).10.1557/JMR.1992.1564Google Scholar
8. Greer, J.R., “Size dependence on strength of gold at the micron scale in the absence of strain gradients”, Ph.D. Dissertation, Stanford University (2005).10.1016/j.actamat.2004.12.031Google Scholar
9. Greer, J.R., et al. ., “Size dependence of mechanical properties of gold at the micron scale in the absence of strain gradients”, Acta Mater. 53, 1821 (2005).10.1016/j.actamat.2004.12.031Google Scholar
10. Bei, H., et al. ., “Strength differences arising from homogeneous versus heterogeneous dislocation nucleation”, Phys. Rev. B 77, 060103R (2008).10.1103/PhysRevB.77.060103Google Scholar
11. Peter, D., et al. ., “Collapse mechanisms for high aspect ratio structures with application to clean processing”, ECS Transactions 25, 241 (2009).10.1149/1.3202659Google Scholar
12. Hill, R., The mathematical theory of plasticity (Oxford Univ. Press, 1950), pp. 97105 Google Scholar
13. Lambropoulos, J. C., et al. ., “Surface microroughness of optical glasses under deterministic microgrinding,” Appl. Opt. 35, 44484462 (1996).10.1364/AO.35.004448Google Scholar