AFM and Ellipsometry Studies of Ultra Thin Ti Film Deposited on a Silicon Wafer

Abstract:

An ultra- thin Ti film with a thickness of less than 30 nm was deposited on the surface of a silicon wafer by the filtered arc deposition system. A novel technique was adopted to create a height step between the coated area and non-coated area (silicon wafer) during deposition. The surface morphology and thickness of the film was detected by atomic force microscopy (AFM). The AFM results showed that the deposited film formed a smooth structure on the silicon wafer and the height step between the coating and silicon wafer was clear enough to give the thickness of the deposited film. The composition of the deposited film was detected by a combined use of Ellipsometry and AFM. Natural oxidisation of Ti (TiO2) was found on the top of the Ti film after deposition, and the thickness of TiO2 was determined by ellipsometry to be about 0.6 nm.

• Periodical: Materials Science Forum (Volumes 773-774)
• Pages: 616-625
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.773-774.616
• Online since: November 2013
• Authors: Bing Jing Lin, Hong Tao Zhu, A. Kiet Tieu, Gerry Triani
• Keywords: AFM, Coating, Deposition, Ellipsometry, Step, Thickness, Ti, TiO₂

References

[1] P. J. Winkler, M. A. Daubler, M. Peters, Applications of Ti Alloys in the European Aerospace Industry, Titanium '92: Science and Technology, Vols 1-3. (1993) 2877-2890.

[2] A. Czyrska-Filemonowicz, P. A. Buffat, E. Czarnowska, T. Wierzchon, Microstructure, properties and biocompatibility of the nitrided Ti-6Al-4V alloy for medical application, Advanced Materials and Technologies. 513 (2006) 15-24.

DOI: 10.4028/www.scientific.net/msf.513.15

[3] T. Mitchell, S. Diplas, P. Tsakiropoulos, Characterisation of corrosion products formed on PVD in situ mechanically worked Mg-Ti alloys, J Alloy Compd. 392 (2005) 127-141.

DOI: 10.1016/j.jallcom.2004.08.086

[4] G. S. Wu, X. M. Wang, K. J. Ding, Y. Y. Zhou, X. Q. Zeng, Corrosion behavior of Ti-Al-N/Ti-Al duplex coating on AZ31 magnesium alloy in NaCl aqueous solution, Mater Charact. 60 (2009) 803-807.

DOI: 10.1016/j.matchar.2009.01.009

[5] S. W. Huang, M. W. Ng, M. Samandi, M. Brandt, Tribological behaviour and microstructure of TiCxN(1-x) coatings deposited by filtered arc, Wear. 252 (2002) 566-579.

DOI: 10.1016/s0043-1648(02)00010-8

[6] H. Savaloni, H. Kangarloo, Influence of film thickness, substrate temperature and nano-structural changes on the optical properties of UHV deposited Ti thin films, J Phys D Appl Phys. 40 (2007) 203-214.

DOI: 10.1088/0022-3727/40/1/016

[7] K. Y. Cai, M. Muller, J. Bossert, A. Rechtenbach, K. D. Jandt, Surface structure and composition of flat titanium thin films as a function of film thickness and evaporation rate, Appl Surf Sci. 250 (2005) 252-267.

DOI: 10.1016/j.apsusc.2005.01.013

[8] H. Savaloni, A. Taherizadeh, A. Zendehnam, Residual stress and structural characteristics in Ti and Cu sputtered films on glass substrates at different substrate temperatures and film thickness, Physica B-Condensed Matter. 349 (2004) 44-55.

DOI: 10.1016/j.physb.2004.01.158

[9] S. Mahmoud, Structure and Optical-Properties of Thin Titanium Films Deposited on Different Substrates, J Mater Sci. 22 (1987) 3693-3697.

DOI: 10.1007/bf01161479

[10] A. Dasgupta, A. Singh, P. K. Parida, R. Ramaseshan, P. Kuppusami, S. Saroja, M. Vijayalakshmi, Structural characteristics of titanium coating on copper substrates, B Mater Sci. 34 (2011) 483-489.

DOI: 10.1007/s12034-011-0118-0

[11] P. G. Hartley, H. Thissen, T. Vaithianathan, H. J. Griesser, A Surface Masking Technique for the Determination of Plasma Polymer Film Thickness by AFM, Plasmas and Polymers. 5 (2000) 47-60.

DOI: 10.1023/a:1009508426115

[12] P. Lemoine, J. P. Quinn, P. D. Maguire, J. A. D. McLaughlin, Measuring the thickness of ultra-thin diamond-like carbon films, Carbon. 44 (2006) 2617-2624.

DOI: 10.1016/j.carbon.2006.04.029

[13] C. Ton-That, A. G. Shard, R. H. Bradley, Thickness of spin-cast polymer thin films determined by angle-resolved XPS and AFM tip-scratch methods, Langmuir. 16 (2000) 2281-2284.

DOI: 10.1021/la990605c

[14] W. L. Yuan, E. A. O'Rear, G. Cho, G. P. Funkhouser, D. T. Glatzhofer, Thin polypyrrole films formed on mica and alumina with and without surfactant present: characterization by scanning probe and optical microscopy, Thin Solid Films. 385 (2001) 96-108.

DOI: 10.1016/s0040-6090(01)00755-6

[15] D. R. G. Mitchell, D. J. Attard, K. S. Finnie, G. Triani, C. J. Barbe, C. Depagne, J. R. Bartlett, TEM and ellipsometry studies of nanolaminate oxide films prepared using atomic layer deposition, Appl Surf Sci. 243 (2005) 265-277.

DOI: 10.1016/j.apsusc.2004.09.070