Preparation and Characterization of Low Dielectric Constant Films Using Silicon Sources

Abstract:

Effect of various silicon sources, such as TEOS, MTES mixed with TEOS and 1,3,5-tris(triethoxymethyl) on SiO₂ films was investigated. The synthesized solutions were used as silicon sources to prepare silica-like backbone films. The investigation showed that all precursors can able to produce the flat and uniform films. An FTIR spectrum confirmed the formation of SiO₂ in film matrix. The results indicated that the internal microstructure of each film is different. The incorporation of less polar bonds such as F and C was carried out using various Si sources, while the introduction of these sources confirmed through FTIR spectra. Optical properties of the films were carried out by using ellipsometric porosometry (EP) measurement. The leakage current density for the films prepared by using TEOS, MTES and 135TTEB was observed to be 2.8 × 10^-7 A/cm², 2.9 × 10^-8 A / cm², and 4.1 × 10^-6 A / cm², respectively, at 1 MV/cm electric field strength by the IV curves obtained by semiconductor characterization after fabricating MIS devices. The calculated dielectric constants from RI of the deposited SiO₂ films were 2.0, 1.9 and 2.5 respectively. When the microstructure of the precursor solution changed, the introduction of atomic morphology or terminal inerted group ratio changed the internal bridging mode of SiO₂, and thereby significantly reduced the dielectric constant and improved insulation.

• Periodical: Materials Science Forum (Volume 993)
• Pages: 927-932
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.993.927
• Online since: May 2020
• Authors: Zhi Wei He, Hong Xiao Lin, Chun Yan Li, Ashok M. Mahajan, Swati A. Gupta, Mei Zhou*
• Keywords: Different Si Source, FTIR, Low Dielectric Constant, Terminal Methyl Groups

References

[1] N. B. Pawar, Y. S. Mhaisagar, A. S. Gaikwad and A. M. Mahajan, Synthesis and characterization of porogen based porous low-k thin films, J. Silicom-Neth. (2017) 439-446.

DOI: 10.1007/s12633-016-9475-z

[2] C.J. Brinker., G.W. Scherer, Sol-gel science: the physics and chemistry of sol-gel processing, first ed., Academic press, New York, (2013).

[3] A. S. Gaikwad, S. A. Gupta and A. M. Mahajan, Influence of HF acid catalyst concentration on properties of aerogel low-k thin films, J. Mater. Res. Express. 3 (2016):086403.

DOI: 10.1088/2053-1591/3/8/086403

[4] M. Zaharescu, A. Jitianu, A. Braileanu, J. Madarász, CS. Novák and G. Pokol, Composition and thermal stability of SiO2-based hybrid materials TEOS-MTEOS system, J. J. Therm. Anal. Calorim. 71 (2003):421-428.

DOI: 10.1023/a:1022883221776

[5] J. C. Echeverria, M. Faustini, J. J. Garrido. Effects of the porous texture and surface chemistry of silica xerogels on the sensitivity of fiber-optic sensors toward VOCs, J. Sensor. Actuat. B-Chem. 222 (2016):1166-1174.

DOI: 10.1016/j.snb.2015.08.010

[6] R. B. Casagrande, S. R. Kunst, L. V. Rossa Beltrami, C. Aguzzoli, R. N. Brandalise and C. F. Malfatti. Pretreatment effect of the pure titanium surface on hybrid coating adhesion based on tetraethoxysilane and methyltriethoxysilane, J. J. Coat. Technol. Res. 15 (2018):1089-1106.

DOI: 10.1007/s11998-017-0035-2

[7] C. Liu, Q. Qi, D. S. Seregin, A. S. Vishnevskiy, Y. Wang, S. Wei, J. Zang, K. A. Vorotilov, F.N. Dultsev and M. R.Baklanov. Effect of terminal methyl groups concentration on properties of organosilicate glass low dielectric constant films, J. Jan. J. Appl. Phyd. 57 (2018) :07MC017SI.

DOI: 10.7567/jjap.57.07mc01

[8] J. A. Burg, M. S. Oliver, T. J. Frot, M. Sherwood, V. Lee, G. dubois and R. Dauskardt. Hyperconnected molecular glass network architectures with exceptional elastic properties, J. Nat. Commun. 8 (2017):10191.

DOI: 10.1038/s41467-017-01305-w

[9] J. Li, R.N. Vrtis, R.G. Ridgeway, M. Xiao, and X. Lei, U.S. Patent, 15,681,102.(2018).

[10] S Seraji, Y Wu, M Forbess, and S. J. Limmer, T. Chou, and G. Cao. Sol-gel-derived mesoporous silica films with low dielectric constants, J. Adv. Mater. 12(2000):1695.

DOI: 10.1002/1521-4095(200011)12:22<1695::aid-adma1695>3.0.co;2-v

[11] S.A. Gupta, A.S. Gaikwad and A. M. Mahajan, Tween-80 based ultra-low-k (ULK) mesoporous films, J. Journal of Materials Science: Materials in Electronics, 28(2017):14763–14768.

DOI: 10.1007/s10854-017-7345-0

[12] Y. S. Mhaisagar and A. M. Mahajan. Synthesis of SiOF nanoporous ultra low-k thin film, J. Journal of Materials Science: Materials in Electronics, 24(2013):4964-4969.

DOI: 10.1007/s10854-013-1508-4

[13] R.K. Gupta, M. Cavas and F. Yakuphanoglu, Structural and Optical Properties of nanostructure CdZno films, Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 95(2012): 107-113.

DOI: 10.1016/j.saa.2012.04.012

[14] Information on https://www.researchgate.net/post/relation_between_refraction_index_and_dielectric_constant.

[15] Information on https://www.tf.uni-kiel.de/matwis/amat/elmat_en/kap_3/backbone/r3_7_1.pdf.