Abstract

Artificial compound eye cameras are an attractive approach to generate imaging systems of maximum miniaturization. Their thickness can be reduced by a factor of two in comparison to miniaturized single aperture cameras with the same pixel size and resolution. The imaging performance of these systems can be improved significantly by the use of micro-optical refractive freeform arrays (RFFA). Due to the complexity of these non-symmetric surface profiles with sag heights larger than 50 µm in combination with extreme profile accuracies better than λ/14 (rms), there is no dedicated fabrication technology currently available. In the presented research, significant improvements in the fabrication of these elements with laser lithography were reached. Therefore, a laser lithographic process based on several coating steps in combination with a multiple exposure strategy was developed that is suitable for the fabrication of arbitrary freeform structures with sag heights up to 60 µm. In order to minimize surface deviations caused by unavoidable process nonlinearities, a compensation strategy based on an empirical process model is used. The achievable accuracy of the proposed method and its limitations were investigated by fabricating a spherical micro lens array for demonstration. The fabricated elements possess a shape deviation of less than 1.3 µm (rms) and can be used as master structures for a subsequent replication process in order to realize a cost efficient mass production of artificial compound eye optics on wafer level.

© 2012 OSA

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  1. R. Völkel, M. Eisner, and K. J. Weible, “Miniaturized imaging systems,” Microelectron. Eng. 67–68, 461–472 (2003).
    [CrossRef]
  2. A. Brueckner, J. Duparré, R. Leitel, P. Dannberg, A. Bräuer, and A. Tünnermann, “Thin wafer-level camera lenses inspired by insect compound eyes,” Opt. Express 18(24), 24379–24394 (2010).
    [CrossRef] [PubMed]
  3. J. Meyer, A. Brückner, R. Leitel, P. Dannberg, A. Bräuer, and A. Tünnermann, “Optical Cluster Eye fabricated on wafer-level,” Opt. Express 19(18), 17506–17519 (2011).
    [CrossRef] [PubMed]
  4. J. Duparré, F. Wippermann, P. Dannberg, and A. Reimann, “Chirped arrays of refractive ellipsoidal microlenses for aberration correction under oblique incidence,” Opt. Express 13(26), 10539–10551 (2005).
    [CrossRef] [PubMed]
  5. F. Wippermann, J. Duparré, P. Schreiber, and P. Dannberg, “Design and fabrication of a chirped array of refractive ellipsoidal micro-lenses for an apposition eye camera objective,” Proc. SPIE 5962, 59622C, 59622C-11 (2005).
    [CrossRef]
  6. F. Wippermann, J. Duparré, and P. Schreiber, “Applications of chirped microlens arrays for aberration compensation and improved system integration,” Proc. SPIE 6289, 628915, 628915-9 (2006).
    [CrossRef]
  7. D. Daly, R. F. Stevens, M. C. Hutley, and N. Davies, “The manufacture of microlenses by melting photoresist,” Meas. Sci. Technol. 1(8), 759–766 (1990).
    [CrossRef]
  8. S. Scheiding, R. Steinkopf, A. Gebhardt, P. Dannberg, S. Risse, R. Eberhardt, and A. Tünnermann, “Aspheric Lens Array Machining and Replication”, EOS Conference at the World of Photonics Congress 2009 - Session: “High Volume Manufacturing of Optical Components”, 15.-17.6.2009, Munich, Germany Proceedings EOS Conference at the World of Photonics Congress 2009 on CD-ROM.
  9. E. Kley, M. Cumme, L.-C. Wittig, and A. Tünnermann, “Fabrication and properties of refractive micro-optical profiles for lenses, lens arrays and beam shaping elements,” Proc. SPIE 4231, 144–152 (2000).
    [CrossRef]
  10. P. Allen, “Laser scanning for semiconductor mask pattern generation,” in Proceedings of the IEEE, vol.90, no.10, pp. 1653- 1669 (2002).
  11. T. Dresel and J. Schwider, “Fabrication of optical components by laser lithography,” Appl. Surf. Sci. 106, 379–382 (1996).
    [CrossRef]
  12. M. T. Gale, G. K. Lang, T. M. Rayner, and H. Schültz, “Fabrication of micro-optical components by laser beam writing in photoresist,” Proc. SPIE 1506, 65–70 (1991).
    [CrossRef]
  13. D. Radtke and U. D. Zeitner, “Laser-lithography on non-planar surfaces,” Opt. Express 15(3), 1167–1174 (2007).
    [CrossRef] [PubMed]
  14. E. Kley, “Continuous profile writing by electron and optical lithography,” Microelectron. Eng. 34(3-4), 261–298 (1997).
    [CrossRef]
  15. M. T. Gale, M. Rossi, and J. Pedersen, “Fabrication of continuous-relief micro-optical elements by direct laser writing in photoresists,” Opt. Eng. 33(11), 3556–3566 (1994).
    [CrossRef]
  16. T. Hessler, M. Rossi, J. Pedersen, M. T. Gale, M. Wegner, D. Steudle, and H. J. Tiziani, “Microlens arrays with spatial variation of the optical functions,” Pure Appl. Opt. 6(6), 673–681 (1997).
    [CrossRef]
  17. T. Hessler, M. Rossi, R. E. Kunz, and M. T. Gale, “Analysis and optimization of fabrication of continuous-relief diffractive optical elements,” Appl. Opt. 37(19), 4069–4079 (1998).
    [CrossRef] [PubMed]
  18. V. P. Korolkov, R. K. Nasyrov, and R. V. Shimansky, “Optimization for direct laser writing of continuous-relief diffractive optical elements,” Proc. SPIE 6732, 6292 (2007).
  19. D. Asselin, P. Topart, L. Sheng, F. Cayer, S. Leclair, and M. Wang, “On-chip replication of high-sag micro-optical components fabricated by direct laser writing,” Proc. SPIE 5720, 222–232 (2005).
    [CrossRef]
  20. T. R. M. Sales, “Structured microlens arrays for beam shaping,” Opt. Eng. 42(11), 3084–3085 (2003).
    [CrossRef]
  21. F. Wippermann, D. Radtke, U. Zeitner, J. W. Duparre, A. Tünnermann, M. Amberg, S. Sinzinger, C. Reinhardt, A. Ovsianikov, and B. N. Chichkov, “Fabrication technologies for chirped refractive microlens arrays,” Proc. SPIE 6288, 62880O (2006).
    [CrossRef]
  22. R. Dammel, Diazonaphthoquinone-Based Resists (SPIE Optical Engineering Press, 1993).
  23. J. Brown and C. Hamel, “Thick resist for MEMS processing,” Proc. SPIE 4592, 334–346 (2001).
    [CrossRef]
  24. V. Kohlmeier, S. Seidemann, Büttgenbach, and H. H. Gatzen, “An investigation on technologies to fabricate microcoils for miniaturized actuator systems,” Microsyst. Technol. 10(3), 175–181 (2004).
  25. M. Kubenz, U. Ostrzinski, F. Reuther, and G. Gruetzner, “Effective baking of thick and ultra-thick photoresist layers by infrared radiation,” Microelectron. Eng. 67–68, 495–501 (2003).
    [CrossRef]
  26. M. Cumme, H. Hartung, L. Wittig, and E. B. Kley, “Thick refractive beam shaping elements applied to laser diodes,” Proc. SPIE 4440, 25–33 (2001).
    [CrossRef]
  27. F. Dill, “Optical lithography,” IEEE Trans. Electron. Dev. 22(7), 440–444 (1975).
    [CrossRef]
  28. F. Dill, W. Hornberger, P. Hauge, and J. Shaw, “Characterization of positive photoresist,” IEEE Trans. Electron. Dev. 22(7), 445–452 (1975).
    [CrossRef]
  29. C. Du, X. Dong, C. Qiu, Q. Deng, and C. Zhou, “Profile control technology for high-performance microlens array,” Opt. Eng. 43(11), 2595 (2004).
    [CrossRef]
  30. X. Dong, C. Du, S. Li, C. Wang, and Y. Fu, “Control approach for form accuracy of microlenses with continuous relief,” Opt. Express 13(5), 1353–1360 (2005).
    [CrossRef] [PubMed]
  31. Y. Hirai, K. Inamoto, T. Sugano, Tsuchiya, and O. Tabata, “Moving mask UV lithography for three-dimensional structuring,” J. Micromech. Microeng. 17(2), 199–206 (2007).
    [CrossRef]
  32. K. Hirai, T. Sugano, Tsuchiya, and O. Tabata, “A three-dimensional microstructuring technique exploiting the positive photoresist property,” J. Micromech. Microeng. 20(6), 065005 (2010).
    [CrossRef]
  33. R. E. Jewett, P. I. Hagouel, A. R. Neureuther, and T. van Duzer, “Line-Profile resist development simulation techniques,” Polym. Eng. Sci. 17(6), 381–384 (1977).
    [CrossRef]
  34. K. Toh, A. Neureuther, and E. Scheckler, “Algorithms for simulation of three-dimensional etching,” IEEE Trans. Comput.- Aided Des. Integr. Circuits Syst 13(5), 616–624 (1994).
    [CrossRef]
  35. A. Maréchal, PhD Thesis “Etude des influences conjuguées des aberrations et de la diffraction sur l’image d’unpoint,” Faculté des Sciences de Paris, (1947).

2011 (1)

2010 (2)

A. Brueckner, J. Duparré, R. Leitel, P. Dannberg, A. Bräuer, and A. Tünnermann, “Thin wafer-level camera lenses inspired by insect compound eyes,” Opt. Express 18(24), 24379–24394 (2010).
[CrossRef] [PubMed]

K. Hirai, T. Sugano, Tsuchiya, and O. Tabata, “A three-dimensional microstructuring technique exploiting the positive photoresist property,” J. Micromech. Microeng. 20(6), 065005 (2010).
[CrossRef]

2007 (3)

Y. Hirai, K. Inamoto, T. Sugano, Tsuchiya, and O. Tabata, “Moving mask UV lithography for three-dimensional structuring,” J. Micromech. Microeng. 17(2), 199–206 (2007).
[CrossRef]

D. Radtke and U. D. Zeitner, “Laser-lithography on non-planar surfaces,” Opt. Express 15(3), 1167–1174 (2007).
[CrossRef] [PubMed]

V. P. Korolkov, R. K. Nasyrov, and R. V. Shimansky, “Optimization for direct laser writing of continuous-relief diffractive optical elements,” Proc. SPIE 6732, 6292 (2007).

2006 (2)

F. Wippermann, D. Radtke, U. Zeitner, J. W. Duparre, A. Tünnermann, M. Amberg, S. Sinzinger, C. Reinhardt, A. Ovsianikov, and B. N. Chichkov, “Fabrication technologies for chirped refractive microlens arrays,” Proc. SPIE 6288, 62880O (2006).
[CrossRef]

F. Wippermann, J. Duparré, and P. Schreiber, “Applications of chirped microlens arrays for aberration compensation and improved system integration,” Proc. SPIE 6289, 628915, 628915-9 (2006).
[CrossRef]

2005 (4)

F. Wippermann, J. Duparré, P. Schreiber, and P. Dannberg, “Design and fabrication of a chirped array of refractive ellipsoidal micro-lenses for an apposition eye camera objective,” Proc. SPIE 5962, 59622C, 59622C-11 (2005).
[CrossRef]

D. Asselin, P. Topart, L. Sheng, F. Cayer, S. Leclair, and M. Wang, “On-chip replication of high-sag micro-optical components fabricated by direct laser writing,” Proc. SPIE 5720, 222–232 (2005).
[CrossRef]

X. Dong, C. Du, S. Li, C. Wang, and Y. Fu, “Control approach for form accuracy of microlenses with continuous relief,” Opt. Express 13(5), 1353–1360 (2005).
[CrossRef] [PubMed]

J. Duparré, F. Wippermann, P. Dannberg, and A. Reimann, “Chirped arrays of refractive ellipsoidal microlenses for aberration correction under oblique incidence,” Opt. Express 13(26), 10539–10551 (2005).
[CrossRef] [PubMed]

2004 (2)

C. Du, X. Dong, C. Qiu, Q. Deng, and C. Zhou, “Profile control technology for high-performance microlens array,” Opt. Eng. 43(11), 2595 (2004).
[CrossRef]

V. Kohlmeier, S. Seidemann, Büttgenbach, and H. H. Gatzen, “An investigation on technologies to fabricate microcoils for miniaturized actuator systems,” Microsyst. Technol. 10(3), 175–181 (2004).

2003 (3)

M. Kubenz, U. Ostrzinski, F. Reuther, and G. Gruetzner, “Effective baking of thick and ultra-thick photoresist layers by infrared radiation,” Microelectron. Eng. 67–68, 495–501 (2003).
[CrossRef]

T. R. M. Sales, “Structured microlens arrays for beam shaping,” Opt. Eng. 42(11), 3084–3085 (2003).
[CrossRef]

R. Völkel, M. Eisner, and K. J. Weible, “Miniaturized imaging systems,” Microelectron. Eng. 67–68, 461–472 (2003).
[CrossRef]

2001 (2)

J. Brown and C. Hamel, “Thick resist for MEMS processing,” Proc. SPIE 4592, 334–346 (2001).
[CrossRef]

M. Cumme, H. Hartung, L. Wittig, and E. B. Kley, “Thick refractive beam shaping elements applied to laser diodes,” Proc. SPIE 4440, 25–33 (2001).
[CrossRef]

2000 (1)

E. Kley, M. Cumme, L.-C. Wittig, and A. Tünnermann, “Fabrication and properties of refractive micro-optical profiles for lenses, lens arrays and beam shaping elements,” Proc. SPIE 4231, 144–152 (2000).
[CrossRef]

1998 (1)

1997 (2)

T. Hessler, M. Rossi, J. Pedersen, M. T. Gale, M. Wegner, D. Steudle, and H. J. Tiziani, “Microlens arrays with spatial variation of the optical functions,” Pure Appl. Opt. 6(6), 673–681 (1997).
[CrossRef]

E. Kley, “Continuous profile writing by electron and optical lithography,” Microelectron. Eng. 34(3-4), 261–298 (1997).
[CrossRef]

1996 (1)

T. Dresel and J. Schwider, “Fabrication of optical components by laser lithography,” Appl. Surf. Sci. 106, 379–382 (1996).
[CrossRef]

1994 (2)

M. T. Gale, M. Rossi, and J. Pedersen, “Fabrication of continuous-relief micro-optical elements by direct laser writing in photoresists,” Opt. Eng. 33(11), 3556–3566 (1994).
[CrossRef]

K. Toh, A. Neureuther, and E. Scheckler, “Algorithms for simulation of three-dimensional etching,” IEEE Trans. Comput.- Aided Des. Integr. Circuits Syst 13(5), 616–624 (1994).
[CrossRef]

1991 (1)

M. T. Gale, G. K. Lang, T. M. Rayner, and H. Schültz, “Fabrication of micro-optical components by laser beam writing in photoresist,” Proc. SPIE 1506, 65–70 (1991).
[CrossRef]

1990 (1)

D. Daly, R. F. Stevens, M. C. Hutley, and N. Davies, “The manufacture of microlenses by melting photoresist,” Meas. Sci. Technol. 1(8), 759–766 (1990).
[CrossRef]

1977 (1)

R. E. Jewett, P. I. Hagouel, A. R. Neureuther, and T. van Duzer, “Line-Profile resist development simulation techniques,” Polym. Eng. Sci. 17(6), 381–384 (1977).
[CrossRef]

1975 (2)

F. Dill, “Optical lithography,” IEEE Trans. Electron. Dev. 22(7), 440–444 (1975).
[CrossRef]

F. Dill, W. Hornberger, P. Hauge, and J. Shaw, “Characterization of positive photoresist,” IEEE Trans. Electron. Dev. 22(7), 445–452 (1975).
[CrossRef]

Amberg, M.

F. Wippermann, D. Radtke, U. Zeitner, J. W. Duparre, A. Tünnermann, M. Amberg, S. Sinzinger, C. Reinhardt, A. Ovsianikov, and B. N. Chichkov, “Fabrication technologies for chirped refractive microlens arrays,” Proc. SPIE 6288, 62880O (2006).
[CrossRef]

Asselin, D.

D. Asselin, P. Topart, L. Sheng, F. Cayer, S. Leclair, and M. Wang, “On-chip replication of high-sag micro-optical components fabricated by direct laser writing,” Proc. SPIE 5720, 222–232 (2005).
[CrossRef]

Bräuer, A.

Brown, J.

J. Brown and C. Hamel, “Thick resist for MEMS processing,” Proc. SPIE 4592, 334–346 (2001).
[CrossRef]

Brückner, A.

Brueckner, A.

Büttgenbach,

V. Kohlmeier, S. Seidemann, Büttgenbach, and H. H. Gatzen, “An investigation on technologies to fabricate microcoils for miniaturized actuator systems,” Microsyst. Technol. 10(3), 175–181 (2004).

Cayer, F.

D. Asselin, P. Topart, L. Sheng, F. Cayer, S. Leclair, and M. Wang, “On-chip replication of high-sag micro-optical components fabricated by direct laser writing,” Proc. SPIE 5720, 222–232 (2005).
[CrossRef]

Chichkov, B. N.

F. Wippermann, D. Radtke, U. Zeitner, J. W. Duparre, A. Tünnermann, M. Amberg, S. Sinzinger, C. Reinhardt, A. Ovsianikov, and B. N. Chichkov, “Fabrication technologies for chirped refractive microlens arrays,” Proc. SPIE 6288, 62880O (2006).
[CrossRef]

Cumme, M.

M. Cumme, H. Hartung, L. Wittig, and E. B. Kley, “Thick refractive beam shaping elements applied to laser diodes,” Proc. SPIE 4440, 25–33 (2001).
[CrossRef]

E. Kley, M. Cumme, L.-C. Wittig, and A. Tünnermann, “Fabrication and properties of refractive micro-optical profiles for lenses, lens arrays and beam shaping elements,” Proc. SPIE 4231, 144–152 (2000).
[CrossRef]

Daly, D.

D. Daly, R. F. Stevens, M. C. Hutley, and N. Davies, “The manufacture of microlenses by melting photoresist,” Meas. Sci. Technol. 1(8), 759–766 (1990).
[CrossRef]

Dannberg, P.

Davies, N.

D. Daly, R. F. Stevens, M. C. Hutley, and N. Davies, “The manufacture of microlenses by melting photoresist,” Meas. Sci. Technol. 1(8), 759–766 (1990).
[CrossRef]

Deng, Q.

C. Du, X. Dong, C. Qiu, Q. Deng, and C. Zhou, “Profile control technology for high-performance microlens array,” Opt. Eng. 43(11), 2595 (2004).
[CrossRef]

Dill, F.

F. Dill, “Optical lithography,” IEEE Trans. Electron. Dev. 22(7), 440–444 (1975).
[CrossRef]

F. Dill, W. Hornberger, P. Hauge, and J. Shaw, “Characterization of positive photoresist,” IEEE Trans. Electron. Dev. 22(7), 445–452 (1975).
[CrossRef]

Dong, X.

X. Dong, C. Du, S. Li, C. Wang, and Y. Fu, “Control approach for form accuracy of microlenses with continuous relief,” Opt. Express 13(5), 1353–1360 (2005).
[CrossRef] [PubMed]

C. Du, X. Dong, C. Qiu, Q. Deng, and C. Zhou, “Profile control technology for high-performance microlens array,” Opt. Eng. 43(11), 2595 (2004).
[CrossRef]

Dresel, T.

T. Dresel and J. Schwider, “Fabrication of optical components by laser lithography,” Appl. Surf. Sci. 106, 379–382 (1996).
[CrossRef]

Du, C.

X. Dong, C. Du, S. Li, C. Wang, and Y. Fu, “Control approach for form accuracy of microlenses with continuous relief,” Opt. Express 13(5), 1353–1360 (2005).
[CrossRef] [PubMed]

C. Du, X. Dong, C. Qiu, Q. Deng, and C. Zhou, “Profile control technology for high-performance microlens array,” Opt. Eng. 43(11), 2595 (2004).
[CrossRef]

Duparre, J. W.

F. Wippermann, D. Radtke, U. Zeitner, J. W. Duparre, A. Tünnermann, M. Amberg, S. Sinzinger, C. Reinhardt, A. Ovsianikov, and B. N. Chichkov, “Fabrication technologies for chirped refractive microlens arrays,” Proc. SPIE 6288, 62880O (2006).
[CrossRef]

Duparré, J.

A. Brueckner, J. Duparré, R. Leitel, P. Dannberg, A. Bräuer, and A. Tünnermann, “Thin wafer-level camera lenses inspired by insect compound eyes,” Opt. Express 18(24), 24379–24394 (2010).
[CrossRef] [PubMed]

F. Wippermann, J. Duparré, and P. Schreiber, “Applications of chirped microlens arrays for aberration compensation and improved system integration,” Proc. SPIE 6289, 628915, 628915-9 (2006).
[CrossRef]

F. Wippermann, J. Duparré, P. Schreiber, and P. Dannberg, “Design and fabrication of a chirped array of refractive ellipsoidal micro-lenses for an apposition eye camera objective,” Proc. SPIE 5962, 59622C, 59622C-11 (2005).
[CrossRef]

J. Duparré, F. Wippermann, P. Dannberg, and A. Reimann, “Chirped arrays of refractive ellipsoidal microlenses for aberration correction under oblique incidence,” Opt. Express 13(26), 10539–10551 (2005).
[CrossRef] [PubMed]

Eisner, M.

R. Völkel, M. Eisner, and K. J. Weible, “Miniaturized imaging systems,” Microelectron. Eng. 67–68, 461–472 (2003).
[CrossRef]

Fu, Y.

Gale, M. T.

T. Hessler, M. Rossi, R. E. Kunz, and M. T. Gale, “Analysis and optimization of fabrication of continuous-relief diffractive optical elements,” Appl. Opt. 37(19), 4069–4079 (1998).
[CrossRef] [PubMed]

T. Hessler, M. Rossi, J. Pedersen, M. T. Gale, M. Wegner, D. Steudle, and H. J. Tiziani, “Microlens arrays with spatial variation of the optical functions,” Pure Appl. Opt. 6(6), 673–681 (1997).
[CrossRef]

M. T. Gale, M. Rossi, and J. Pedersen, “Fabrication of continuous-relief micro-optical elements by direct laser writing in photoresists,” Opt. Eng. 33(11), 3556–3566 (1994).
[CrossRef]

M. T. Gale, G. K. Lang, T. M. Rayner, and H. Schültz, “Fabrication of micro-optical components by laser beam writing in photoresist,” Proc. SPIE 1506, 65–70 (1991).
[CrossRef]

Gatzen, H. H.

V. Kohlmeier, S. Seidemann, Büttgenbach, and H. H. Gatzen, “An investigation on technologies to fabricate microcoils for miniaturized actuator systems,” Microsyst. Technol. 10(3), 175–181 (2004).

Gruetzner, G.

M. Kubenz, U. Ostrzinski, F. Reuther, and G. Gruetzner, “Effective baking of thick and ultra-thick photoresist layers by infrared radiation,” Microelectron. Eng. 67–68, 495–501 (2003).
[CrossRef]

Hagouel, P. I.

R. E. Jewett, P. I. Hagouel, A. R. Neureuther, and T. van Duzer, “Line-Profile resist development simulation techniques,” Polym. Eng. Sci. 17(6), 381–384 (1977).
[CrossRef]

Hamel, C.

J. Brown and C. Hamel, “Thick resist for MEMS processing,” Proc. SPIE 4592, 334–346 (2001).
[CrossRef]

Hartung, H.

M. Cumme, H. Hartung, L. Wittig, and E. B. Kley, “Thick refractive beam shaping elements applied to laser diodes,” Proc. SPIE 4440, 25–33 (2001).
[CrossRef]

Hauge, P.

F. Dill, W. Hornberger, P. Hauge, and J. Shaw, “Characterization of positive photoresist,” IEEE Trans. Electron. Dev. 22(7), 445–452 (1975).
[CrossRef]

Hessler, T.

T. Hessler, M. Rossi, R. E. Kunz, and M. T. Gale, “Analysis and optimization of fabrication of continuous-relief diffractive optical elements,” Appl. Opt. 37(19), 4069–4079 (1998).
[CrossRef] [PubMed]

T. Hessler, M. Rossi, J. Pedersen, M. T. Gale, M. Wegner, D. Steudle, and H. J. Tiziani, “Microlens arrays with spatial variation of the optical functions,” Pure Appl. Opt. 6(6), 673–681 (1997).
[CrossRef]

Hirai, K.

K. Hirai, T. Sugano, Tsuchiya, and O. Tabata, “A three-dimensional microstructuring technique exploiting the positive photoresist property,” J. Micromech. Microeng. 20(6), 065005 (2010).
[CrossRef]

Hirai, Y.

Y. Hirai, K. Inamoto, T. Sugano, Tsuchiya, and O. Tabata, “Moving mask UV lithography for three-dimensional structuring,” J. Micromech. Microeng. 17(2), 199–206 (2007).
[CrossRef]

Hornberger, W.

F. Dill, W. Hornberger, P. Hauge, and J. Shaw, “Characterization of positive photoresist,” IEEE Trans. Electron. Dev. 22(7), 445–452 (1975).
[CrossRef]

Hutley, M. C.

D. Daly, R. F. Stevens, M. C. Hutley, and N. Davies, “The manufacture of microlenses by melting photoresist,” Meas. Sci. Technol. 1(8), 759–766 (1990).
[CrossRef]

Inamoto, K.

Y. Hirai, K. Inamoto, T. Sugano, Tsuchiya, and O. Tabata, “Moving mask UV lithography for three-dimensional structuring,” J. Micromech. Microeng. 17(2), 199–206 (2007).
[CrossRef]

Jewett, R. E.

R. E. Jewett, P. I. Hagouel, A. R. Neureuther, and T. van Duzer, “Line-Profile resist development simulation techniques,” Polym. Eng. Sci. 17(6), 381–384 (1977).
[CrossRef]

Kley, E.

E. Kley, M. Cumme, L.-C. Wittig, and A. Tünnermann, “Fabrication and properties of refractive micro-optical profiles for lenses, lens arrays and beam shaping elements,” Proc. SPIE 4231, 144–152 (2000).
[CrossRef]

E. Kley, “Continuous profile writing by electron and optical lithography,” Microelectron. Eng. 34(3-4), 261–298 (1997).
[CrossRef]

Kley, E. B.

M. Cumme, H. Hartung, L. Wittig, and E. B. Kley, “Thick refractive beam shaping elements applied to laser diodes,” Proc. SPIE 4440, 25–33 (2001).
[CrossRef]

Kohlmeier, V.

V. Kohlmeier, S. Seidemann, Büttgenbach, and H. H. Gatzen, “An investigation on technologies to fabricate microcoils for miniaturized actuator systems,” Microsyst. Technol. 10(3), 175–181 (2004).

Korolkov, V. P.

V. P. Korolkov, R. K. Nasyrov, and R. V. Shimansky, “Optimization for direct laser writing of continuous-relief diffractive optical elements,” Proc. SPIE 6732, 6292 (2007).

Kubenz, M.

M. Kubenz, U. Ostrzinski, F. Reuther, and G. Gruetzner, “Effective baking of thick and ultra-thick photoresist layers by infrared radiation,” Microelectron. Eng. 67–68, 495–501 (2003).
[CrossRef]

Kunz, R. E.

Lang, G. K.

M. T. Gale, G. K. Lang, T. M. Rayner, and H. Schültz, “Fabrication of micro-optical components by laser beam writing in photoresist,” Proc. SPIE 1506, 65–70 (1991).
[CrossRef]

Leclair, S.

D. Asselin, P. Topart, L. Sheng, F. Cayer, S. Leclair, and M. Wang, “On-chip replication of high-sag micro-optical components fabricated by direct laser writing,” Proc. SPIE 5720, 222–232 (2005).
[CrossRef]

Leitel, R.

Li, S.

Meyer, J.

Nasyrov, R. K.

V. P. Korolkov, R. K. Nasyrov, and R. V. Shimansky, “Optimization for direct laser writing of continuous-relief diffractive optical elements,” Proc. SPIE 6732, 6292 (2007).

Neureuther, A.

K. Toh, A. Neureuther, and E. Scheckler, “Algorithms for simulation of three-dimensional etching,” IEEE Trans. Comput.- Aided Des. Integr. Circuits Syst 13(5), 616–624 (1994).
[CrossRef]

Neureuther, A. R.

R. E. Jewett, P. I. Hagouel, A. R. Neureuther, and T. van Duzer, “Line-Profile resist development simulation techniques,” Polym. Eng. Sci. 17(6), 381–384 (1977).
[CrossRef]

Ostrzinski, U.

M. Kubenz, U. Ostrzinski, F. Reuther, and G. Gruetzner, “Effective baking of thick and ultra-thick photoresist layers by infrared radiation,” Microelectron. Eng. 67–68, 495–501 (2003).
[CrossRef]

Ovsianikov, A.

F. Wippermann, D. Radtke, U. Zeitner, J. W. Duparre, A. Tünnermann, M. Amberg, S. Sinzinger, C. Reinhardt, A. Ovsianikov, and B. N. Chichkov, “Fabrication technologies for chirped refractive microlens arrays,” Proc. SPIE 6288, 62880O (2006).
[CrossRef]

Pedersen, J.

T. Hessler, M. Rossi, J. Pedersen, M. T. Gale, M. Wegner, D. Steudle, and H. J. Tiziani, “Microlens arrays with spatial variation of the optical functions,” Pure Appl. Opt. 6(6), 673–681 (1997).
[CrossRef]

M. T. Gale, M. Rossi, and J. Pedersen, “Fabrication of continuous-relief micro-optical elements by direct laser writing in photoresists,” Opt. Eng. 33(11), 3556–3566 (1994).
[CrossRef]

Qiu, C.

C. Du, X. Dong, C. Qiu, Q. Deng, and C. Zhou, “Profile control technology for high-performance microlens array,” Opt. Eng. 43(11), 2595 (2004).
[CrossRef]

Radtke, D.

D. Radtke and U. D. Zeitner, “Laser-lithography on non-planar surfaces,” Opt. Express 15(3), 1167–1174 (2007).
[CrossRef] [PubMed]

F. Wippermann, D. Radtke, U. Zeitner, J. W. Duparre, A. Tünnermann, M. Amberg, S. Sinzinger, C. Reinhardt, A. Ovsianikov, and B. N. Chichkov, “Fabrication technologies for chirped refractive microlens arrays,” Proc. SPIE 6288, 62880O (2006).
[CrossRef]

Rayner, T. M.

M. T. Gale, G. K. Lang, T. M. Rayner, and H. Schültz, “Fabrication of micro-optical components by laser beam writing in photoresist,” Proc. SPIE 1506, 65–70 (1991).
[CrossRef]

Reimann, A.

Reinhardt, C.

F. Wippermann, D. Radtke, U. Zeitner, J. W. Duparre, A. Tünnermann, M. Amberg, S. Sinzinger, C. Reinhardt, A. Ovsianikov, and B. N. Chichkov, “Fabrication technologies for chirped refractive microlens arrays,” Proc. SPIE 6288, 62880O (2006).
[CrossRef]

Reuther, F.

M. Kubenz, U. Ostrzinski, F. Reuther, and G. Gruetzner, “Effective baking of thick and ultra-thick photoresist layers by infrared radiation,” Microelectron. Eng. 67–68, 495–501 (2003).
[CrossRef]

Rossi, M.

T. Hessler, M. Rossi, R. E. Kunz, and M. T. Gale, “Analysis and optimization of fabrication of continuous-relief diffractive optical elements,” Appl. Opt. 37(19), 4069–4079 (1998).
[CrossRef] [PubMed]

T. Hessler, M. Rossi, J. Pedersen, M. T. Gale, M. Wegner, D. Steudle, and H. J. Tiziani, “Microlens arrays with spatial variation of the optical functions,” Pure Appl. Opt. 6(6), 673–681 (1997).
[CrossRef]

M. T. Gale, M. Rossi, and J. Pedersen, “Fabrication of continuous-relief micro-optical elements by direct laser writing in photoresists,” Opt. Eng. 33(11), 3556–3566 (1994).
[CrossRef]

Sales, T. R. M.

T. R. M. Sales, “Structured microlens arrays for beam shaping,” Opt. Eng. 42(11), 3084–3085 (2003).
[CrossRef]

Scheckler, E.

K. Toh, A. Neureuther, and E. Scheckler, “Algorithms for simulation of three-dimensional etching,” IEEE Trans. Comput.- Aided Des. Integr. Circuits Syst 13(5), 616–624 (1994).
[CrossRef]

Schreiber, P.

F. Wippermann, J. Duparré, and P. Schreiber, “Applications of chirped microlens arrays for aberration compensation and improved system integration,” Proc. SPIE 6289, 628915, 628915-9 (2006).
[CrossRef]

F. Wippermann, J. Duparré, P. Schreiber, and P. Dannberg, “Design and fabrication of a chirped array of refractive ellipsoidal micro-lenses for an apposition eye camera objective,” Proc. SPIE 5962, 59622C, 59622C-11 (2005).
[CrossRef]

Schültz, H.

M. T. Gale, G. K. Lang, T. M. Rayner, and H. Schültz, “Fabrication of micro-optical components by laser beam writing in photoresist,” Proc. SPIE 1506, 65–70 (1991).
[CrossRef]

Schwider, J.

T. Dresel and J. Schwider, “Fabrication of optical components by laser lithography,” Appl. Surf. Sci. 106, 379–382 (1996).
[CrossRef]

Seidemann, S.

V. Kohlmeier, S. Seidemann, Büttgenbach, and H. H. Gatzen, “An investigation on technologies to fabricate microcoils for miniaturized actuator systems,” Microsyst. Technol. 10(3), 175–181 (2004).

Shaw, J.

F. Dill, W. Hornberger, P. Hauge, and J. Shaw, “Characterization of positive photoresist,” IEEE Trans. Electron. Dev. 22(7), 445–452 (1975).
[CrossRef]

Sheng, L.

D. Asselin, P. Topart, L. Sheng, F. Cayer, S. Leclair, and M. Wang, “On-chip replication of high-sag micro-optical components fabricated by direct laser writing,” Proc. SPIE 5720, 222–232 (2005).
[CrossRef]

Shimansky, R. V.

V. P. Korolkov, R. K. Nasyrov, and R. V. Shimansky, “Optimization for direct laser writing of continuous-relief diffractive optical elements,” Proc. SPIE 6732, 6292 (2007).

Sinzinger, S.

F. Wippermann, D. Radtke, U. Zeitner, J. W. Duparre, A. Tünnermann, M. Amberg, S. Sinzinger, C. Reinhardt, A. Ovsianikov, and B. N. Chichkov, “Fabrication technologies for chirped refractive microlens arrays,” Proc. SPIE 6288, 62880O (2006).
[CrossRef]

Steudle, D.

T. Hessler, M. Rossi, J. Pedersen, M. T. Gale, M. Wegner, D. Steudle, and H. J. Tiziani, “Microlens arrays with spatial variation of the optical functions,” Pure Appl. Opt. 6(6), 673–681 (1997).
[CrossRef]

Stevens, R. F.

D. Daly, R. F. Stevens, M. C. Hutley, and N. Davies, “The manufacture of microlenses by melting photoresist,” Meas. Sci. Technol. 1(8), 759–766 (1990).
[CrossRef]

Sugano, T.

K. Hirai, T. Sugano, Tsuchiya, and O. Tabata, “A three-dimensional microstructuring technique exploiting the positive photoresist property,” J. Micromech. Microeng. 20(6), 065005 (2010).
[CrossRef]

Y. Hirai, K. Inamoto, T. Sugano, Tsuchiya, and O. Tabata, “Moving mask UV lithography for three-dimensional structuring,” J. Micromech. Microeng. 17(2), 199–206 (2007).
[CrossRef]

Tabata, O.

K. Hirai, T. Sugano, Tsuchiya, and O. Tabata, “A three-dimensional microstructuring technique exploiting the positive photoresist property,” J. Micromech. Microeng. 20(6), 065005 (2010).
[CrossRef]

Y. Hirai, K. Inamoto, T. Sugano, Tsuchiya, and O. Tabata, “Moving mask UV lithography for three-dimensional structuring,” J. Micromech. Microeng. 17(2), 199–206 (2007).
[CrossRef]

Tiziani, H. J.

T. Hessler, M. Rossi, J. Pedersen, M. T. Gale, M. Wegner, D. Steudle, and H. J. Tiziani, “Microlens arrays with spatial variation of the optical functions,” Pure Appl. Opt. 6(6), 673–681 (1997).
[CrossRef]

Toh, K.

K. Toh, A. Neureuther, and E. Scheckler, “Algorithms for simulation of three-dimensional etching,” IEEE Trans. Comput.- Aided Des. Integr. Circuits Syst 13(5), 616–624 (1994).
[CrossRef]

Topart, P.

D. Asselin, P. Topart, L. Sheng, F. Cayer, S. Leclair, and M. Wang, “On-chip replication of high-sag micro-optical components fabricated by direct laser writing,” Proc. SPIE 5720, 222–232 (2005).
[CrossRef]

Tsuchiya,

K. Hirai, T. Sugano, Tsuchiya, and O. Tabata, “A three-dimensional microstructuring technique exploiting the positive photoresist property,” J. Micromech. Microeng. 20(6), 065005 (2010).
[CrossRef]

Y. Hirai, K. Inamoto, T. Sugano, Tsuchiya, and O. Tabata, “Moving mask UV lithography for three-dimensional structuring,” J. Micromech. Microeng. 17(2), 199–206 (2007).
[CrossRef]

Tünnermann, A.

J. Meyer, A. Brückner, R. Leitel, P. Dannberg, A. Bräuer, and A. Tünnermann, “Optical Cluster Eye fabricated on wafer-level,” Opt. Express 19(18), 17506–17519 (2011).
[CrossRef] [PubMed]

A. Brueckner, J. Duparré, R. Leitel, P. Dannberg, A. Bräuer, and A. Tünnermann, “Thin wafer-level camera lenses inspired by insect compound eyes,” Opt. Express 18(24), 24379–24394 (2010).
[CrossRef] [PubMed]

F. Wippermann, D. Radtke, U. Zeitner, J. W. Duparre, A. Tünnermann, M. Amberg, S. Sinzinger, C. Reinhardt, A. Ovsianikov, and B. N. Chichkov, “Fabrication technologies for chirped refractive microlens arrays,” Proc. SPIE 6288, 62880O (2006).
[CrossRef]

E. Kley, M. Cumme, L.-C. Wittig, and A. Tünnermann, “Fabrication and properties of refractive micro-optical profiles for lenses, lens arrays and beam shaping elements,” Proc. SPIE 4231, 144–152 (2000).
[CrossRef]

van Duzer, T.

R. E. Jewett, P. I. Hagouel, A. R. Neureuther, and T. van Duzer, “Line-Profile resist development simulation techniques,” Polym. Eng. Sci. 17(6), 381–384 (1977).
[CrossRef]

Völkel, R.

R. Völkel, M. Eisner, and K. J. Weible, “Miniaturized imaging systems,” Microelectron. Eng. 67–68, 461–472 (2003).
[CrossRef]

Wang, C.

Wang, M.

D. Asselin, P. Topart, L. Sheng, F. Cayer, S. Leclair, and M. Wang, “On-chip replication of high-sag micro-optical components fabricated by direct laser writing,” Proc. SPIE 5720, 222–232 (2005).
[CrossRef]

Wegner, M.

T. Hessler, M. Rossi, J. Pedersen, M. T. Gale, M. Wegner, D. Steudle, and H. J. Tiziani, “Microlens arrays with spatial variation of the optical functions,” Pure Appl. Opt. 6(6), 673–681 (1997).
[CrossRef]

Weible, K. J.

R. Völkel, M. Eisner, and K. J. Weible, “Miniaturized imaging systems,” Microelectron. Eng. 67–68, 461–472 (2003).
[CrossRef]

Wippermann, F.

F. Wippermann, D. Radtke, U. Zeitner, J. W. Duparre, A. Tünnermann, M. Amberg, S. Sinzinger, C. Reinhardt, A. Ovsianikov, and B. N. Chichkov, “Fabrication technologies for chirped refractive microlens arrays,” Proc. SPIE 6288, 62880O (2006).
[CrossRef]

F. Wippermann, J. Duparré, and P. Schreiber, “Applications of chirped microlens arrays for aberration compensation and improved system integration,” Proc. SPIE 6289, 628915, 628915-9 (2006).
[CrossRef]

F. Wippermann, J. Duparré, P. Schreiber, and P. Dannberg, “Design and fabrication of a chirped array of refractive ellipsoidal micro-lenses for an apposition eye camera objective,” Proc. SPIE 5962, 59622C, 59622C-11 (2005).
[CrossRef]

J. Duparré, F. Wippermann, P. Dannberg, and A. Reimann, “Chirped arrays of refractive ellipsoidal microlenses for aberration correction under oblique incidence,” Opt. Express 13(26), 10539–10551 (2005).
[CrossRef] [PubMed]

Wittig, L.

M. Cumme, H. Hartung, L. Wittig, and E. B. Kley, “Thick refractive beam shaping elements applied to laser diodes,” Proc. SPIE 4440, 25–33 (2001).
[CrossRef]

Wittig, L.-C.

E. Kley, M. Cumme, L.-C. Wittig, and A. Tünnermann, “Fabrication and properties of refractive micro-optical profiles for lenses, lens arrays and beam shaping elements,” Proc. SPIE 4231, 144–152 (2000).
[CrossRef]

Zeitner, U.

F. Wippermann, D. Radtke, U. Zeitner, J. W. Duparre, A. Tünnermann, M. Amberg, S. Sinzinger, C. Reinhardt, A. Ovsianikov, and B. N. Chichkov, “Fabrication technologies for chirped refractive microlens arrays,” Proc. SPIE 6288, 62880O (2006).
[CrossRef]

Zeitner, U. D.

Zhou, C.

C. Du, X. Dong, C. Qiu, Q. Deng, and C. Zhou, “Profile control technology for high-performance microlens array,” Opt. Eng. 43(11), 2595 (2004).
[CrossRef]

Appl. Opt. (1)

Appl. Surf. Sci. (1)

T. Dresel and J. Schwider, “Fabrication of optical components by laser lithography,” Appl. Surf. Sci. 106, 379–382 (1996).
[CrossRef]

IEEE Trans. Comput.- Aided Des. Integr. Circuits Syst (1)

K. Toh, A. Neureuther, and E. Scheckler, “Algorithms for simulation of three-dimensional etching,” IEEE Trans. Comput.- Aided Des. Integr. Circuits Syst 13(5), 616–624 (1994).
[CrossRef]

IEEE Trans. Electron. Dev. (2)

F. Dill, “Optical lithography,” IEEE Trans. Electron. Dev. 22(7), 440–444 (1975).
[CrossRef]

F. Dill, W. Hornberger, P. Hauge, and J. Shaw, “Characterization of positive photoresist,” IEEE Trans. Electron. Dev. 22(7), 445–452 (1975).
[CrossRef]

J. Micromech. Microeng. (2)

Y. Hirai, K. Inamoto, T. Sugano, Tsuchiya, and O. Tabata, “Moving mask UV lithography for three-dimensional structuring,” J. Micromech. Microeng. 17(2), 199–206 (2007).
[CrossRef]

K. Hirai, T. Sugano, Tsuchiya, and O. Tabata, “A three-dimensional microstructuring technique exploiting the positive photoresist property,” J. Micromech. Microeng. 20(6), 065005 (2010).
[CrossRef]

Meas. Sci. Technol. (1)

D. Daly, R. F. Stevens, M. C. Hutley, and N. Davies, “The manufacture of microlenses by melting photoresist,” Meas. Sci. Technol. 1(8), 759–766 (1990).
[CrossRef]

Microelectron. Eng. (3)

M. Kubenz, U. Ostrzinski, F. Reuther, and G. Gruetzner, “Effective baking of thick and ultra-thick photoresist layers by infrared radiation,” Microelectron. Eng. 67–68, 495–501 (2003).
[CrossRef]

E. Kley, “Continuous profile writing by electron and optical lithography,” Microelectron. Eng. 34(3-4), 261–298 (1997).
[CrossRef]

R. Völkel, M. Eisner, and K. J. Weible, “Miniaturized imaging systems,” Microelectron. Eng. 67–68, 461–472 (2003).
[CrossRef]

Microsyst. Technol. (1)

V. Kohlmeier, S. Seidemann, Büttgenbach, and H. H. Gatzen, “An investigation on technologies to fabricate microcoils for miniaturized actuator systems,” Microsyst. Technol. 10(3), 175–181 (2004).

Opt. Eng. (3)

T. R. M. Sales, “Structured microlens arrays for beam shaping,” Opt. Eng. 42(11), 3084–3085 (2003).
[CrossRef]

M. T. Gale, M. Rossi, and J. Pedersen, “Fabrication of continuous-relief micro-optical elements by direct laser writing in photoresists,” Opt. Eng. 33(11), 3556–3566 (1994).
[CrossRef]

C. Du, X. Dong, C. Qiu, Q. Deng, and C. Zhou, “Profile control technology for high-performance microlens array,” Opt. Eng. 43(11), 2595 (2004).
[CrossRef]

Opt. Express (5)

Polym. Eng. Sci. (1)

R. E. Jewett, P. I. Hagouel, A. R. Neureuther, and T. van Duzer, “Line-Profile resist development simulation techniques,” Polym. Eng. Sci. 17(6), 381–384 (1977).
[CrossRef]

Proc. SPIE (9)

F. Wippermann, D. Radtke, U. Zeitner, J. W. Duparre, A. Tünnermann, M. Amberg, S. Sinzinger, C. Reinhardt, A. Ovsianikov, and B. N. Chichkov, “Fabrication technologies for chirped refractive microlens arrays,” Proc. SPIE 6288, 62880O (2006).
[CrossRef]

E. Kley, M. Cumme, L.-C. Wittig, and A. Tünnermann, “Fabrication and properties of refractive micro-optical profiles for lenses, lens arrays and beam shaping elements,” Proc. SPIE 4231, 144–152 (2000).
[CrossRef]

J. Brown and C. Hamel, “Thick resist for MEMS processing,” Proc. SPIE 4592, 334–346 (2001).
[CrossRef]

M. Cumme, H. Hartung, L. Wittig, and E. B. Kley, “Thick refractive beam shaping elements applied to laser diodes,” Proc. SPIE 4440, 25–33 (2001).
[CrossRef]

F. Wippermann, J. Duparré, P. Schreiber, and P. Dannberg, “Design and fabrication of a chirped array of refractive ellipsoidal micro-lenses for an apposition eye camera objective,” Proc. SPIE 5962, 59622C, 59622C-11 (2005).
[CrossRef]

F. Wippermann, J. Duparré, and P. Schreiber, “Applications of chirped microlens arrays for aberration compensation and improved system integration,” Proc. SPIE 6289, 628915, 628915-9 (2006).
[CrossRef]

M. T. Gale, G. K. Lang, T. M. Rayner, and H. Schültz, “Fabrication of micro-optical components by laser beam writing in photoresist,” Proc. SPIE 1506, 65–70 (1991).
[CrossRef]

V. P. Korolkov, R. K. Nasyrov, and R. V. Shimansky, “Optimization for direct laser writing of continuous-relief diffractive optical elements,” Proc. SPIE 6732, 6292 (2007).

D. Asselin, P. Topart, L. Sheng, F. Cayer, S. Leclair, and M. Wang, “On-chip replication of high-sag micro-optical components fabricated by direct laser writing,” Proc. SPIE 5720, 222–232 (2005).
[CrossRef]

Pure Appl. Opt. (1)

T. Hessler, M. Rossi, J. Pedersen, M. T. Gale, M. Wegner, D. Steudle, and H. J. Tiziani, “Microlens arrays with spatial variation of the optical functions,” Pure Appl. Opt. 6(6), 673–681 (1997).
[CrossRef]

Other (4)

A. Maréchal, PhD Thesis “Etude des influences conjuguées des aberrations et de la diffraction sur l’image d’unpoint,” Faculté des Sciences de Paris, (1947).

S. Scheiding, R. Steinkopf, A. Gebhardt, P. Dannberg, S. Risse, R. Eberhardt, and A. Tünnermann, “Aspheric Lens Array Machining and Replication”, EOS Conference at the World of Photonics Congress 2009 - Session: “High Volume Manufacturing of Optical Components”, 15.-17.6.2009, Munich, Germany Proceedings EOS Conference at the World of Photonics Congress 2009 on CD-ROM.

P. Allen, “Laser scanning for semiconductor mask pattern generation,” in Proceedings of the IEEE, vol.90, no.10, pp. 1653- 1669 (2002).

R. Dammel, Diazonaphthoquinone-Based Resists (SPIE Optical Engineering Press, 1993).

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Figures (10)

Fig. 1
Fig. 1

(a) Photograph of an artificial compound eye camera in comparison to a one cent coin to demonstrate the extremely small size of the imaging system. (b) Surface profile of a refractive freeform array (RFFA). Each single lenslet in the array has its optimized shape in order to correct for optical aberrations and is bounded by vertical edges to ensure a maximum fill factor.

Fig. 2
Fig. 2

Surface profiles of a blazed test structure measured with a white light interferometer. All structures were exposed by a fivefold exposure process and developed for 120s. The temperature TB and duration tB of the final baking step was optimized in order to prevent the occurrence of macroscopic nitrogen bubbles. First, the duration was increased from (a) 23 min to (b) 60 min and finally to (c) 100 min at constant temperature TB. Afterwards, the temperature TB was increased from (d) 90°C to (e) 95°C and (f) 100°C at an optimized duration tB of the final baking step.

Fig. 3
Fig. 3

(a) Comparison of optimized baking conditions to prevent the formation of nitrogen bubbles and non-optimized baking conditions showing a strong formation of nitrogen bubbles for a fivefold exposure regime. (b) Maximum achievable structure height with optimized baking conditions for different numbers of exposures.

Fig. 4
Fig. 4

(a) Comparison of the photoresist response for optimized and non-optimized baking conditions and (b) schematic representation of the isotropic characteristic of the development process.

Fig. 5
Fig. 5

(a) Test structure consisting of different dose step areas used to measure the relation between structure height and development time. (b) Measured structure height vs. development time for the different dose steps shown in Fig. 5(a).

Fig. 6
Fig. 6

(a) Empirical process description for a tenfold exposure regime. The relation between structure height and development time for all 128 dose steps has been determined by a cubic spline interpolation of experimentally obtained height values for several dose steps at different development times. (b) Calculated development rates for every single of the 128 available dose values vs. development time. (c) Development rate as a function of development time and position for a spherical lens profile.

Fig. 7
Fig. 7

Schematic representation of the proposed iterative algorithm to compensate for process nonlinearities.

Fig. 8
Fig. 8

(a) Roughness (rms) of a dose step area after 120s development time. (b) Measured roughness of dose step areas for different development times for a tenfold exposure process.

Fig. 9
Fig. 9

(a) Relation between the uncertainty of the determined structure heights of the dose step fields in the test structures and the simulated surface profiles. (b) Measured intensity fluctuation of the laser scan.

Fig. 10
Fig. 10

Fabricated spherical lens profile by applying a tenfold exposure process in combination with optimized baking conditions without any compensation of process nonlinearities (dashed blue line), measured lens profile based on the proposed compensation strategy (solid blue line), and ideal lens profile (dotted blue line).

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