DOI: https://doi.org/10.20535/2305-9001.2012.65.33953

SURFACE ROUGHENING OF ULTRA-THIN COPPER FILM

М. О. Цисар

Abstract


Metal ultra-thin films are widely used in microelectronic devices. Stress-induced morphological instability is the one of the more important defect creation processes in these films. This process related to the tends that roughen film surface by mass diffusion during growth or heat treatment. This article gives an overview of theoretical and experimental studies on cupper film surface roughening. It is shown that diffusional atomic flux along the film surface related to the strain caused by lattice mismatch drives in such a way that an initially flat film evolves into an undulating profile with surface valleys with singular stress concentration near the valley tip. The stress concentration at cycloid-like surface valleys caused by roughening is found to create dislocations of various characters that participate in the overall strain relaxation. The experimental data were compared with the analytical data obtained on the basis of the developed physical-mathematical model of the surface formation topography. The discrepancy between experimental data and the model is ≈ 0,5% in the lateral direction and ≈ 3% in the direction of axis z


Keywords


ultrathin copper film; stress-strain state; scanning tunnelling microscope; diamond tip

References


1. Zhengwen L., Antti R., Roy G. Atomic layer deposition of ultrathin copper metal films from a liquid copper amidinate precursor // J. Elect. Soc. – 2006. – 153, 11. – p.787-794.

2. Yoshihiro N., Shirou O., Hiroshi K. Multilevel interconnect technology for 45-nm node CMOS LSIs // J. Sci. Tech. – 2010. – 46, 1. – p.120 -127.

3. Matthews J., Blakeslee A. Defects in epitaxial multilayers // J. Crys. Grow. – 1974. – 37. – p.118-125.

4. Sun B., Suo Z. A finite element method for simulating interface motion—II. Large shape change due to surface diffusion // Mech. Mat. – 1997. – 45,12. – p. 4953-4962.

5. Sébastien B., Harry A., Alexander Ya. The surface of helium crystals // Rev. Mod. Phys. – 2005. – 77, 1. – p.317–370.

6. Дмитриев А.И., Никонов А.Ю., Псахье С.Г. Молекулярно-динамическое изучение отклика бикристалла меди в условиях сдвигового нагружения // Письма в ЖТФ. – 2010. – 36, 17. – c.16-22.

7. Yang X., Weinan E. Misfit elastic energy and a continuum model for epitaxial growth with elasticity on vicinal surfaces // Phys. Rev. B. – 2004. – 69, 3. – p. 035409- 035425.

8. Gao H. In Modern Theory of Anisotropic Elasticity and Applications / ed. J. Wu, T. Ting, D. Barnett. // Philadelphia: SIAM. – 1991. – p.139.

9. Huajian G. Mass-conserved morphological evolution of hypocycloid cavities: a model of diffusive crack initiation with no associated energy barrier // Proc. R. Soc. Lond. A. – 1995. – 448. – p.465-483.

10. Simmons J.G. Generalized formula for the electronic tunnel effect between similar electrodes separated by a thin insulating film // J. Appl. Phys. – 1963. – 34. – p.1793-1803.

11. Lysenko O.G., Novikov N.V., Gontar A.G. Semiconductive diamond tip for combined scanning probe microscopy// Journal of Superhard Materials. – 2006. – 28, 6.– p.9-18.


GOST Style Citations


1. Zhengwen L., Antti R., Roy G. Atomic layer deposition of ultrathin copper metal films from a liquid copper amidinate precursor // J. Elect. Soc. – 2006. – 153, 11. – p.787-794.

2. Yoshihiro N., Shirou O., Hiroshi K. Multilevel interconnect technology for 45-nm node CMOS LSIs // J. Sci. Tech. – 2010. – 46, 1. – p.120 -127.

3. Matthews J., Blakeslee A. Defects in epitaxial multilayers // J. Crys. Grow. – 1974. – 37. – p.118-125.

4. Sun B., Suo Z. A finite element method for simulating interface motion—II. Large shape change due to surface diffusion // Mech. Mat. – 1997. – 45,12. – p. 4953-4962.

5. Sébastien B., Harry A., Alexander Ya. The surface of helium crystals // Rev. Mod. Phys. – 2005. – 77, 1. – p.317–370.

6. Дмитриев А.И., Никонов А.Ю., Псахье С.Г. Молекулярно-динамическое изучение отклика бикристалла меди в условиях сдвигового нагружения // Письма в ЖТФ. – 2010. – 36, 17. – c.16-22.

7. Yang X., Weinan E. Misfit elastic energy and a continuum model for epitaxial growth with elasticity on vicinal surfaces // Phys. Rev. B. – 2004. – 69, 3. – p. 035409- 035425.

8. Gao H. In Modern Theory of Anisotropic Elasticity and Applications / ed. J. Wu, T. Ting, D. Barnett. // Philadelphia: SIAM. – 1991. – p.139.

9. Huajian G. Mass-conserved morphological evolution of hypocycloid cavities: a model of diffusive crack initiation with no associated energy barrier // Proc. R. Soc. Lond. A. – 1995. – 448. – p.465-483.

10. Simmons J.G. Generalized formula for the electronic tunnel effect between similar electrodes separated by a thin insulating film // J. Appl. Phys. – 1963. – 34. – p.1793-1803.

11. Lysenko O.G., Novikov N.V., Gontar A.G. Semiconductive diamond tip for combined scanning probe microscopy// Journal of Superhard Materials. – 2006. – 28, 6.– p.9-18.





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