Abstract

Hafnium dioxide films deposited using electron-beam evaporation tend to exhibit high tensile stresses, particularly when deposited on low-thermal-expansion substrates for use in a low-relative-humidity environment. Hafnia has been shown to be a critical material, however, for use in high-peak-power laser coatings, providing exceptional deposition control and laser-damage resistance. To correct for tensile thin-film stresses in hafnia/silica multilayer coatings, alumina compensation layers were incorporated in the multilayer design. Determination of the stresses resulting from alumina layers in different coating designs has led to the realization of the influence of water diffusion and the diffusion-barrier properties of alumina that must be considered. The inclusion of alumina layers in a hafnia/silica multilayer provides the ability to produce low-compressive-stress, high-laser-damage-threshold coatings.

© 2012 OSA

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References

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    [CrossRef]
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    [CrossRef] [PubMed]
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    [CrossRef]
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    [CrossRef]
  24. Y. Shen, H. He, S. Shao, Z. Fan, and J. Shao, “Influences of the film thickness on residual stress of the HfO2 thin films,” Rare Metal. Mater. Eng.36, 412–415 (2007).
  25. J. B. Oliver and D. Talbot, “Optimization of deposition uniformity for large-aperture National Ignition Facility substrates in a planetary rotation system,” Appl. Opt.45(13), 3097–3105 (2006).
    [CrossRef] [PubMed]
  26. D. J. Smith, A. Staley, R. Eriksson, and G. Algar, “Counter-rotating planetary design for large rectangular substrates,” in Proceedings of the 41st Annual Technical Conference of the Society of Vacuum Coaters (Society of Vacuum Coaters, Albuquerque, NM, 1998), 193−196.
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2011

2007

Y. Shen, H. He, S. Shao, Z. Fan, and J. Shao, “Influences of the film thickness on residual stress of the HfO2 thin films,” Rare Metal. Mater. Eng.36, 412–415 (2007).

2006

2002

J. Proost and F. Spaepen, “Evolution of the growth stress, stiffness, and microstructure of alumina thin films during vapor deposition,” J. Appl. Phys.91(1), 204–216 (2002).
[CrossRef]

R. Thielsch, A. Gatto, J. Heber, and N. Kaiser, “A comparative study of the UV optical and structural properties of SiO2, Al2O3, and HfO2 single layers deposited by reactive evaporation, ion-assisted deposition and plasma ion-assisted deposition,” Thin Solid Films410(1-2), 86–93 (2002).
[CrossRef]

2000

M. Henyk, D. Wolfframm, and J. Reif, “Ultra short laser pulse induced charged particle emission from wide bandgap crystals,” Appl. Surf. Sci.168(1-4), 263–266 (2000).
[CrossRef]

1998

M. Reichling, A. Bodemann, and N. Kaiser, “Defect induced laser damage in oxide multilayer coatings for 248 nm,” Thin Solid Films320(2), 264–279 (1998).
[CrossRef]

1997

S. Papernov and A. W. Schmid, “Localized absorption effects during 351 nm, pulsed laser irradiation of dielectric multilayer thin films,” J. Appl. Phys.82(11), 5422–5432 (1997).
[CrossRef]

1995

H. Leplan, B. Geenen, J. Y. Robic, and Y. Pauleau, “Residual stresses in evaporated silicon dioxide thin films: Correlation with deposition parameters and aging behavior,” J. Appl. Phys.78(2), 962–968 (1995).
[CrossRef]

1993

1909

G. G. Stoney, “The tension of metallic films deposited by electrolysis,” Proc. R. Soc. Lond., A Contain. Pap. Math. Phys. Character82(553), 172–175 (1909).
[CrossRef]

Bodemann, A.

M. Reichling, A. Bodemann, and N. Kaiser, “Defect induced laser damage in oxide multilayer coatings for 248 nm,” Thin Solid Films320(2), 264–279 (1998).
[CrossRef]

Brinkley, I.

Chow, R.

Chrzan, Z. R.

Falabella, S.

Fan, Z.

Y. Shen, H. He, S. Shao, Z. Fan, and J. Shao, “Influences of the film thickness on residual stress of the HfO2 thin films,” Rare Metal. Mater. Eng.36, 412–415 (2007).

Gatto, A.

R. Thielsch, A. Gatto, J. Heber, and N. Kaiser, “A comparative study of the UV optical and structural properties of SiO2, Al2O3, and HfO2 single layers deposited by reactive evaporation, ion-assisted deposition and plasma ion-assisted deposition,” Thin Solid Films410(1-2), 86–93 (2002).
[CrossRef]

Geenen, B.

H. Leplan, B. Geenen, J. Y. Robic, and Y. Pauleau, “Residual stresses in evaporated silicon dioxide thin films: Correlation with deposition parameters and aging behavior,” J. Appl. Phys.78(2), 962–968 (1995).
[CrossRef]

Gibson, D. R.

Hand, R. D.

He, H.

Y. Shen, H. He, S. Shao, Z. Fan, and J. Shao, “Influences of the film thickness on residual stress of the HfO2 thin films,” Rare Metal. Mater. Eng.36, 412–415 (2007).

Heber, J.

R. Thielsch, A. Gatto, J. Heber, and N. Kaiser, “A comparative study of the UV optical and structural properties of SiO2, Al2O3, and HfO2 single layers deposited by reactive evaporation, ion-assisted deposition and plasma ion-assisted deposition,” Thin Solid Films410(1-2), 86–93 (2002).
[CrossRef]

Henyk, M.

M. Henyk, D. Wolfframm, and J. Reif, “Ultra short laser pulse induced charged particle emission from wide bandgap crystals,” Appl. Surf. Sci.168(1-4), 263–266 (2000).
[CrossRef]

Kaiser, N.

R. Thielsch, A. Gatto, J. Heber, and N. Kaiser, “A comparative study of the UV optical and structural properties of SiO2, Al2O3, and HfO2 single layers deposited by reactive evaporation, ion-assisted deposition and plasma ion-assisted deposition,” Thin Solid Films410(1-2), 86–93 (2002).
[CrossRef]

M. Reichling, A. Bodemann, and N. Kaiser, “Defect induced laser damage in oxide multilayer coatings for 248 nm,” Thin Solid Films320(2), 264–279 (1998).
[CrossRef]

Kozlov, A.

Kozlowski, M. R.

Kupinski, P.

Lambropoulos, J. C.

Leplan, H.

H. Leplan, B. Geenen, J. Y. Robic, and Y. Pauleau, “Residual stresses in evaporated silicon dioxide thin films: Correlation with deposition parameters and aging behavior,” J. Appl. Phys.78(2), 962–968 (1995).
[CrossRef]

Loomis, G. E.

Oliver, J. B.

Papernov, S.

Pauleau, Y.

H. Leplan, B. Geenen, J. Y. Robic, and Y. Pauleau, “Residual stresses in evaporated silicon dioxide thin films: Correlation with deposition parameters and aging behavior,” J. Appl. Phys.78(2), 962–968 (1995).
[CrossRef]

Placido, F.

Proost, J.

J. Proost and F. Spaepen, “Evolution of the growth stress, stiffness, and microstructure of alumina thin films during vapor deposition,” J. Appl. Phys.91(1), 204–216 (2002).
[CrossRef]

Rainer, F.

Reichling, M.

M. Reichling, A. Bodemann, and N. Kaiser, “Defect induced laser damage in oxide multilayer coatings for 248 nm,” Thin Solid Films320(2), 264–279 (1998).
[CrossRef]

Reif, J.

M. Henyk, D. Wolfframm, and J. Reif, “Ultra short laser pulse induced charged particle emission from wide bandgap crystals,” Appl. Surf. Sci.168(1-4), 263–266 (2000).
[CrossRef]

Rigatti, A. L.

Robic, J. Y.

H. Leplan, B. Geenen, J. Y. Robic, and Y. Pauleau, “Residual stresses in evaporated silicon dioxide thin films: Correlation with deposition parameters and aging behavior,” J. Appl. Phys.78(2), 962–968 (1995).
[CrossRef]

Sadowski, D.

Schmid, A. W.

Shao, J.

Y. Shen, H. He, S. Shao, Z. Fan, and J. Shao, “Influences of the film thickness on residual stress of the HfO2 thin films,” Rare Metal. Mater. Eng.36, 412–415 (2007).

Shao, S.

Y. Shen, H. He, S. Shao, Z. Fan, and J. Shao, “Influences of the film thickness on residual stress of the HfO2 thin films,” Rare Metal. Mater. Eng.36, 412–415 (2007).

Shen, Y.

Y. Shen, H. He, S. Shao, Z. Fan, and J. Shao, “Influences of the film thickness on residual stress of the HfO2 thin films,” Rare Metal. Mater. Eng.36, 412–415 (2007).

Spaepen, F.

J. Proost and F. Spaepen, “Evolution of the growth stress, stiffness, and microstructure of alumina thin films during vapor deposition,” J. Appl. Phys.91(1), 204–216 (2002).
[CrossRef]

Spaulding, J.

Stolz, C. J.

Stoney, G. G.

G. G. Stoney, “The tension of metallic films deposited by electrolysis,” Proc. R. Soc. Lond., A Contain. Pap. Math. Phys. Character82(553), 172–175 (1909).
[CrossRef]

Talbot, D.

Thielsch, R.

R. Thielsch, A. Gatto, J. Heber, and N. Kaiser, “A comparative study of the UV optical and structural properties of SiO2, Al2O3, and HfO2 single layers deposited by reactive evaporation, ion-assisted deposition and plasma ion-assisted deposition,” Thin Solid Films410(1-2), 86–93 (2002).
[CrossRef]

Wolfframm, D.

M. Henyk, D. Wolfframm, and J. Reif, “Ultra short laser pulse induced charged particle emission from wide bandgap crystals,” Appl. Surf. Sci.168(1-4), 263–266 (2000).
[CrossRef]

Appl. Opt.

Appl. Surf. Sci.

M. Henyk, D. Wolfframm, and J. Reif, “Ultra short laser pulse induced charged particle emission from wide bandgap crystals,” Appl. Surf. Sci.168(1-4), 263–266 (2000).
[CrossRef]

J. Appl. Phys.

S. Papernov and A. W. Schmid, “Localized absorption effects during 351 nm, pulsed laser irradiation of dielectric multilayer thin films,” J. Appl. Phys.82(11), 5422–5432 (1997).
[CrossRef]

J. Proost and F. Spaepen, “Evolution of the growth stress, stiffness, and microstructure of alumina thin films during vapor deposition,” J. Appl. Phys.91(1), 204–216 (2002).
[CrossRef]

H. Leplan, B. Geenen, J. Y. Robic, and Y. Pauleau, “Residual stresses in evaporated silicon dioxide thin films: Correlation with deposition parameters and aging behavior,” J. Appl. Phys.78(2), 962–968 (1995).
[CrossRef]

Proc. R. Soc. Lond., A Contain. Pap. Math. Phys. Character

G. G. Stoney, “The tension of metallic films deposited by electrolysis,” Proc. R. Soc. Lond., A Contain. Pap. Math. Phys. Character82(553), 172–175 (1909).
[CrossRef]

Rare Metal. Mater. Eng.

Y. Shen, H. He, S. Shao, Z. Fan, and J. Shao, “Influences of the film thickness on residual stress of the HfO2 thin films,” Rare Metal. Mater. Eng.36, 412–415 (2007).

Thin Solid Films

M. Reichling, A. Bodemann, and N. Kaiser, “Defect induced laser damage in oxide multilayer coatings for 248 nm,” Thin Solid Films320(2), 264–279 (1998).
[CrossRef]

R. Thielsch, A. Gatto, J. Heber, and N. Kaiser, “A comparative study of the UV optical and structural properties of SiO2, Al2O3, and HfO2 single layers deposited by reactive evaporation, ion-assisted deposition and plasma ion-assisted deposition,” Thin Solid Films410(1-2), 86–93 (2002).
[CrossRef]

Other

D. J. Smith, A. Staley, R. Eriksson, and G. Algar, “Counter-rotating planetary design for large rectangular substrates,” in Proceedings of the 41st Annual Technical Conference of the Society of Vacuum Coaters (Society of Vacuum Coaters, Albuquerque, NM, 1998), 193−196.

A. V. Tikhonravov and M. K. Trubetskov, OptiLayer Thin Film Software, Optilayer Ltd., http://www.optilayer.com (9 June 2005).

J. W. Hutchison and T. Y. Wu eds. Advances in Applied Mechanics (Academic Press, 1992), 29.

J. W. Hutchison and Z. Suo, “Mixed mode cracking in layered materials,” in Advances in Applied Mechanics29, J. W. Hutchison and T. Y. Wu eds. (Academic Press, 1992), 63−191.

A. Tikhonravov, M. Trubetskov, T. Amotchkina, and M. Kokarev, “Key role of the coating total optical thickness in solving design problems,” in Advances in Optical Thin Films C. Amra, N. Kaiser, and H. A. Macleod eds., (SPIE, Bellingham, WA, 2004), 5250, 312–321.

M. Ohring, Materials Science of Thin Films: Deposition and Structure 2nd ed. (Academic Press, 2002), 723−730.

B. Pinot, H. Leplan, F. Houbre, E. Lavastre, J. C. Poncetta, and G. Chabassier, “Laser Mégajoule 1.06μm mirrors production, with very high laser damage threshold,” in Laser-Induced Damage in Optical Materials 2001 G. J. Exarhos, A. H. Guenther, K. L. Lewis, M. J. Soileau, and C. J. Stolz eds. (SPIE, Bellingham, WA, 2002), 4679, 234–241.

C. J. Stolz, “Status of NIF mirror technologies for completion of the NIF facility,” in Advances in Optical Thin Films III N. Kaiser, M. Lequime, and H. A. Macleod eds. (SPIE, Bellingham, WA, 2008), 7101, Paper 710115.

D. J. Smith, M. McCullough, C. Smith, T. Mikami, and T. Jitsuno, “Low stress ion-assisted coatings on fused silica substrates for large aperture laser pulse compression gratings,” in Laser-Induced Damage in Optical Materials:2008 G. J. Exarhos, D. Ristau, M. J. Soileau, and C. J. Stolz eds. (SPIE, Bellingham, WA, 2008), 7132, Paper 71320E.

L. B. Freund and S. Suresh, Thin Film Materials: Stress, Defect Formation, and Surface Evolution (Cambridge University Press, Cambridge, UK, 2003), 60–83.

E. Lavastre, J. Néauport, J. Duchesne, H. Leplan, and F. Houbre, “Polarizers coatings for the Laser Megajoule prototype,” in Optical Interference Coatings OSA Technical Digest (Optical Society of America, Washington, DC, 2004), Paper TuF3.

J. B. Oliver, P. Kupinski, A. L. Rigatti, A. W. Schmid, J. C. Lambropoulos, S. Papernov, A. Kozlov, and R. D. Hand, “Modification of stresses in evaporated hafnia coatings for use in vacuum,” in Optical Interference Coatings OSA Technical Digest (Optical Society of America, Washington, DC, 2010), Paper WD6.

J. F. Anzellotti, D. J. Smith, R. J. Sczupak, and Z. R. Chrzan, “Stress and environmental shift characteristics of HfO2/SiO2 multilayer coatings,” in Laser-Induced Damage in Optical Materials:1996 H. E. Bennett, A. H. Guenther, M. R. Kozlowski, B. E. Newnam, and M. J. Soileau eds. (SPIE, Bellingham, WA, 1997), 2966, 258−264.

J. B. Oliver, J. Howe, A. Rigatti, D. J. Smith, and C. Stolz, “High precision coating technology for large aperture NIF optics,” in Optical Interference Coatings OSA Technical Digest (Optical Society of America, Washington, DC, 2001), Paper ThD2.

J. B. Oliver, A. L. Rigatti, J. D. Howe, J. Keck, J. Szczepanski, A. W. Schmid, S. Papernov, A. Kozlov, and T. Z. Kosc, “Thin-film polarizers for the OMEGA EP laser system,” in Laser-Induced Damage in Optical Materials:2005 G. J. Exarhos, A. H. Guenther, K. L. Lewis, D. Ristau, M. J. Soileau, and C. J. Stolz eds. (SPIE, Bellingham, WA, 2005), 5991, 394−401.

J. B. Oliver, S. Papernov, A. W. Schmid, and J. C. Lambropoulos, “Optimization of laser-damage resistance of evaporated hafnia films at 351 nm,” in Laser-Induced Damage in Optical Materials:2008 G. J. Exarhos, D. Ristau, M. J. Soileau, and C. J. Stolz eds. (SPIE, Bellingham, WA, 2008), 7132, Paper 71320J.

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Figures (8)

Fig. 1
Fig. 1

Scanning electron microscope (SEM) imaging of the initiation site and crack that forms as a result of the high tensile stress in the film. A defect site in the coating provides an initiation site for tensile stress failure, while tearing of the film is evident within the crack that forms.

Fig. 2
Fig. 2

Refractive-index profile of a hafnia/silica/alumina high-reflector coating. Selected hafnia layers are replaced with equivalent-optical-thickness alumina layers, with the alumina layers being equally distributed throughout the overall thickness of the coating.

Fig. 3
Fig. 3

Change in stress in an alumina/silica coating as a function of time in dry nitrogen. Note that the stress changes quite slowly, corresponding to a change in the reversible film stress as water is removed from the pores of the coating, leading to instability in the optical performance over an extended period of time as the surface flatness continues to change.

Fig. 4
Fig. 4

Diffusion-based model assumes a given alumina layer acts as a water-diffusion barrier, influencing the water content and the corresponding stress of all layers below it. As depicted, alumina layer #1 would influence the stress of layers 2 to 8. Buried within the multilayer coating structure, layer #5 would affect the stresses in only layers 6 to 8.

Fig. 5
Fig. 5

Cross-sectional scanning electron micrographs of the polarizer coating modified with four alumina layers. The alumina layer appears to have a more-columnar structure than the surrounding silica layers, which appear amorphous. The hafnia layers appear columnar and much brighter in the image.

Fig. 6
Fig. 6

Photometric measurement of a Brewster-angle polarizer installed on OMEGA EP, utilizing alumina for stress control in a dry environment. This polarizer coating provides high transmission and contrast over a wavelength range of 30 nm with incident 1053-nm light.

Fig. 7
Fig. 7

Change in photometric performance of a hafnia/silica polarizer coating containing alumina layers. Note that similar to the stress changes in Fig. 4, the optical performance of the coating changes significantly over an extended period of time in a dry nitrogen environment. In this case, measurements were performed over a period of approximately 8 days.

Fig. 8
Fig. 8

Multilayer dielectric coating containing alumina layers 2 days after deposition. Note the “mottled” appearance of the coating color in reflection, indicating an irregular absorption of water into the coating structure.

Tables (4)

Tables Icon

Table 1 Quarter-wave high-reflector coatings for 1053 nm with different numbers of alumina layers replacing hafnia layers. Film stress is determined from surface flatness measurements on a Zygo New View white-light interferometer, with a negative stress being compressive and a positive stress being tensile.

Tables Icon

Table 2 Solutions to the system of equations incorporating interfacial stresses describing the individual stress contributions. All stresses are expressed in MPa.

Tables Icon

Table 3 Calculated values for individual material stresses incorporating the influence of alumina layers as water-diffusion barriers. Solution assumes kH = kL = 1 μm–1.

Tables Icon

Table 4 Measured versus modeled multilayer stresses using the water-diffusion stress model. All samples coated in the primary deposition system model the stress within 6 MPa of the measured value, within the margin of error of the stress measurement.

Equations (10)

Equations on this page are rendered with MathJax. Learn more.

σ= E s t s 2 6( 1 ν s ) t f R ,
h c = Γ E ¯ f Z σ 2 ,
σ 1 t 1 + σ 2 t 2 ++ σ n t n = E s t s 2 6( 1 ν s )R ,
σ total = σ 1 t 1 + σ 2 t 2 ++ σ n t n i t i
σ total = σ H T H + σ L T L + σ A T A T H + T L + T A ,
σ total = σ H T H + σ L T L + σ A T A T H + T L + T A + σ H/L I H/L + σ A/L I A/L ,
[ T H1 T L1 T A1 I H/L1 I A/L1 T H2 T L2 T A2 I H/L2 I A/L2 T H3 T L3 T A3 I H/L3 I A/L3 T H4 T L4 T A4 I H/L4 I A/L4 T H5 T L5 T A5 I H/L5 I A/L5 ]×[ σ H σ L σ A σ H/L σ A/L ]=[ σ total1 σ total2 σ total3 σ total4 σ total5 ],
[ T H1 T L1 T A1 I H/L1 I A/L1 T H2 T L2 T A2 I H/L2 I A/L2 T H3 T L3 T A3 I H/L3 I A/L3 T H4 T L4 T A4 I H/L4 I A/L4 T H5 T L5 T A5 I H/L5 I A/L5 ] 1 ×[ σ total1 σ total2 σ total3 σ total4 σ total5 ]=[ σ H σ L σ A σ H/L σ A/L ].
i t H i ( σ H + D H e k H j=0 i t A j ) + i t L i ( σ L + D L e k L j=0 i t A j ) + i t A i σ A i t H i + i t L i + i t A i = σ total
T H σ L H + T L σ L + T A σ A + D H i t H i e k H j=0 i t A j + D L i t L i e k L j=0 i t A j =( T H + T L + T A ) σ total .

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