White Papers Preface

NanoMaker software is based on R&D activity performed mainly in Institute of Microelectronics Technology RAS since 1989.
During this time improvements of e-beam technology processes and setup operating were developed and implemented in the software in close contact with experimentalists and technologists (see selected reference list below).

I. Contributions to electron beam technology

• proximity correction, guaranteed accuracy of the correction [1, 2, 8, 11]
  Main advantage of the "simple compensation" method developed for proximity correction in comparison to other correction procedures is its guaranteed accuracy.
• models and simulation methods for development of positive [4, 5] and negative resists [6]
  Simulation of development after exposure allows one to predict result of lithography with high confidence
• 3D lithography (3D proximity correction and development) [8, 9, 11, 25]
  Special methods and procedures were suggested to fabricate desirable relieves (shape of resist surface) [8] with main applications in diffractive optics (calculated holograms, photonic structure) and cell biology [27].
• direct measurements of proximity parameters [7, 10, 17] (data base of proximity parameters)
  Quality and accuracy of lithography depends on proper value of proximity parameters [17]. NanoMaker contains a database for the parameters as function of substrate material and accelerating voltage. The data base were accumulated for several years as result of special experiments. Difficulty of experimental measurement is defined by large difference in scale of the parameters (for example beam diameter (Alpha) belongs to range ten(s) nanometer where as proximity distance (Beta) is hundreds times larger). Special experimental method (fitting before measurement) was developed for definition of the proximity parameters [7, 10].

II. Software improvements of lithographic machine operation

Much attention and efforts were devoted to elimination of sources and reasons of accuracy losses of e-beam lithographs.

• distortion correction [14]
  One of such reasons is distortion (static nonlinear errors in beam position far from the center of a scanfield). NanoMaker contains special procedures for distortion compensation during writing. NanoMaker allows one to measure (to characterize) distortion of a particular SEM (or a lithograph) with a special procedure as well.
• delays compensation [14]
  Another source of accuracy loss is delay of beam position on exposed substrate in comparison to desirable (addressed) value. A special procedure for measurement of delay parameters of a lithograph is implemented in NanoMaker so NanoMaker is able to compensate delay errors on "fly" what results to significant reducing total exposure time and simplifying exposure (blank system now is not necessary).
• control of non-SEM lithographs [12, 13] and hysteresis compensation in Scanning Probe (AFM) machines [23].
  NanoMaker can control scanning devices of different types for example setup of focused ion beam [12, 13] and scanning probe microscope. A new type of errors is found in the latter device, NanoMaker contains a mode for compensation of hysteresis (long-term temporary distortion) and procedures for hysteresis parameters definition [23].

• diffractive optics
  Ability to fabricate predisigned relieves based on 3D proximity correction are using for fabrication of diffractive optics of high efficiency like Fresnell zone plates, kinoform optics and calculated holograms [14, 15].
  
• X-ray diffractive optics
  Proximity correction implemented in NanoMaker turned to be very important for fabrication of high quality X-ray diffractive optics [21, 22]
  
• heating effects
  Usage of high throughput e-beam machines with variable beam shape and ultimate current density can result to temperature increasing at exposure area. Method for consideration of e-beam heating contribution in exposure dose is developed [18, 19]. Heating during exposure results to overexposure therefore an approach for heating effect compensation is suggested [20].
  
• Micro/Nano devices
  Some selected examples of microdevices fabrication and testing could be found in [13, 24, 25, 26].

1. V.V.Aristov, B.N.Gaifullin, A.A.Svintsov, S.I.Zaitsev, R.R. Jede, H.F.Raith, Accuracy of proximity correction in electron lithography after development, J.Vac.Sci.Technol. B 10(6),Nov/Dec (1992) 2459-2467
2. V.V.Aristov, A.I.Erko, B.N. Gaifullin, A.A. Svintsov, S.I. Zaitsev, R.R.Jede,H.F.Raith, PROXY - A New Approach For Proximity Correction , Microelectronic Engineering 17 (1992) 413-416
4. S. I. Zaistev, A. A. Svintsov, Theory of isotropic local etching. Problem statement and basic equation, Poverhnost’, 4 (1986) 27-31).
5. S. I. Zaistev, A. A. Svintsov, Theory of isotropic local etching. Properties and some analytical solution, Poverhnost’, 1 (1987) p47-52).
6. V.V.Aristov, T.B.Borsenko, V.A.Kudryashov, A.A.Svintsov,S.I.Zaitsev. Investigation of structure profiles in negative resists Microelectronic Engineering 5 (1986) 329-334.
7. .V.Dubonos, B.N.Gaifullin, H.F.Raith, A.A.Svintsov, S.I.Zaitsev, Evaluation, verification and error determination of proximity parameters (alpha,beta and eta) in electron beam lithography, Microelectronic Engineering 21 (1993) 293-296
8. S.V.Dubonos, B.N.Gaifullin, H.F.Raith, A.A.Svintsov, S.I.Zaitsev, Proximity correction for 3D structures. Microelectronic Engineering 27 (1995) 195-198
9. V.V.Aristov, S.V.Dubonos, R.Ya.Dyachenko, B.N.Gaifullin, V.N.Matveev, H.Raith, A.A.Svintsov, and S.I.Zaitsev. Three-dimension design in electron beam lithography. J.Vac.Sci.Technol. B13(6),Nov/Dec 1995
10. L. I. Aparshina, S. V. Dubonos, S. V. Maksimov, A. A. Svintsov, and S. I. Zaitsev, Energy dependence of proximity parameters investigated by fitting before measurement tests, J. Vac. Sci. Technol. B, Vol. 15, No. 6, Nov/Dec 1997 pp. 2298-2302
11. V.V.Aristov, S.V.Dubonos, B.N.Gaifullin, A.A.Svintsov, S.I.Zaitsev,H.F.Raith. Micro- and Nano- E-Beam Lithography using PROXY. Baltic Electronics Conference /October 7-11, 1996/ pp.121-124, Tallinn, Estonia.
12. V.V. Aristov et al. A new approach to fabrication of nanostructures, Nanotechnology 6, 1995, p 35-39.
13. A. Yu. Kasumov et al, Supercurrents through single-walled carbon nanotubes, Science, v. 284 1999, pp 1508-1510
14. S.V. Dubonos, H.F. Raith, A.A. Svintsov, S.I. Zaitsev, New Writing Routines for SEM Based E-Beam Lithography, Microprocessing and Nanothechnology’99, July 1999, Iokohama, Japan. (Award for the most impressive poster)
15. V.V.Aristov, S.V.Dubonos, R.Ya.Dyachenko, B.N.Gaifullin, V.N.Matveev, A.A.Svintsov, S.I.Zaitsev. Creation of Diffractive Optical Elements by One Step E-beam Lithography for Optoelectronics and X-ray Lithography. Baltic Electronics Conference /October 7-11,96/ pp. 483-486, Tallinn, Estonia
16. S.V.Babin, I.Kostitsh, A.A.Svintsov, Direct measurement of thermoeffect influence of resist sensitivity in EBL. Microelectronic Engineering 17 (1992) 41-44
17. S.V.Babin, and A.A.Svintsov, Effect of resist development process on the determination of proximity function in electron lithography. Microelectronic Engineering 17 (1992) 417-420
18. S.V.Babin, I.Kostitsh, A.A.Svintsov, Model and measurement of resist heating effect in EBL. SPIE Vol. 1671 (1992) 93-97
19. A.A.Svintsov, S.I.Zaitsev, Simulation of heating in powerful electron lithography. Microelectronic Engineering 27 (1995) 187-190
20. A.A.Svintsov, and S.I.Zaitsev. Dose contribution of heating in electron beam lithography J.Vac.Sci.Technol. B13(6),Nov/Dec 1995
21. V. Aristov, M. Chukalina, A. Firsov, T. Ishikawa, S. Kikuta, Y. Kohmura, A. Svintsov, S. Zaitsev, X-Ray Optics differential Contrast: design, optimization, simulation, fabrication., XRM99, AIP Conference Proc. 507, 554-557, 2000
22. A.A. Firsov, A.A. Svintsov, S.I. Zaitsev, A.Erko, V.V. Aristov, The first synthetic X-ray hologram: results, Opt. Commun. 202(2002) 55-59
23. A. A. Svintsov, O. V. Trofimov, S. I. Zaitsev, AFM control for lithography, to be published
24. A.K.Geim, S.V.Dubonos, I.V.Grigorieva, K.S.Novoselov, F.M.Peeters and V.A.Schweigert, Non-quantized penetration of magnetic field in the vortex state of Superconductors, Nature 407 (2000), p.55-57
25. S.V.Dubonos, A.K.Geim, K.S.Novoselov and I.V.Grigorieva, Spontaneous magnetization changes and nonlocal effects in mesoscopic ferromagnet-superconductor structures, Phys.Rev.B 65 (2002) 2230513
26. D.Y. Vodolazov, F.M. Peeters, S.V. Dubonos, and A.K. Geim, Multiple flux jumps and irreversible behavior of thin Al superconducting rings, Phys. Rev. B 67, (2003) 054506
27. Zaitsev S.I., Curtis A. Wilkinson C., Misrostructures which polarizes cell movement, to be published.