Fabrication and Electrical Characterization of Al/BaxSr1-xTiO3/Pt/SiO2/Si Configuration for FeFET Applications

The ferroelectric behavior of barium strontium titanate (BST) in thin film form has been investigated in order to study the possibility of using BST for ferroelectric gate-field effect transistor (FeFET) for memory devices application. BST thin films have been fabricated as Al/BST/Pt/SiO2/Si-gate configuration. The variation of the dielectric constant (ε) and tan δ with frequency have been studied to ensure the dielectric quality of the material. The results show that at low frequencies, ε increases as the Ba content increases, whereas at high frequencies, it shows the opposite variation, which is attributed to the dipole dynamics. tan δ shows low values with a peak at the mid-frequency range. The ferroelectric behavior of the Al/BST/Pt/SiO2/Si has been investigated using C-V characteristics. The results show that the strength of the ferroelectric hysteresis loop increases as the Ba content increases; this is attributed to the grain size and dipole dynamics effect.

Authors:

• Ala'eddin A. Saif
• Z. A. Z. Jamal
• Z. Sauli
• P. Poopalan

Keywords:

• BST thin film
• Electrical properties
• Ferroelectrichysteresis
• Ferroelectric FET.

References:

[1] A. Roy, A. Dhar, D. Bhattacharya, S. K Ray, "Structural and electrical
properties of metal-ferroelectric-insulator-semiconductor structure of
Al/SrBi2Ta2O9/HfO2/Si using HfO2 buffer," J. Phys. D: Appl. Phys., vol.
41, pp. 095408, 2008.
[2] Y. P. Wang, L. Zhou, X. B. Lu, Z. G. Liu, "C-V characteristics of
Pt/PbZr0.53Ti0.47O3/LaAlO3/Si and
Pt/PbZr0.53Ti0.47O3/La0.85Sr0.15CoO3/LaAlO3/Si structures for ferroelectric
gate FET memory," App. Surf. Sci., vol. 205, pp. 176-181, 2003.
[3] D. R. Patil, , S. A. Lokare, R. S. Devan, S. S. Chougule, C. M.
Kanamadi, Y. D. Kolekar, B. K. Chougule, "Studies on Electrical and
Dielectric Properties of Ba1−xSrxTiO3," Mater. Chem. Phys., Vol. 104,
pp. 254-257, 2007.
[4] E. Ngo, W. D. Nothwang, C. Hubbard, S. Hirsch, M. W. Cole, W.
Chang, S. W. Kirchoffer, J. M. Pond, "Ba1-xSrxTiO3 ased Thin Films for
Next Generation Devices," Army Research Laboratory 2004: Report
Number: ARL-TN-228, Aberdeen Proving Ground, MD 21005-5069.
[5] S. K. Pandey, A. R. James, C. Prakash, T. C. Goel, K. Zimik, "Electrical
properties of PZT thin films grown by sol-gel and PLD using a seed
layer," Mater. Sci. Eng. B, vol. 112, pp. 96-100, 2004.
[6] Ala-eddin A. Saif, P. Poopalan, "Electrical properties of metal-
ferroelectric-insulator-semiconductor structure using BaxSr1-xTiO3 for
ferroelectric-gate field effect transistor," Solid State Electron, vol. 62,
pp. 25-30, 2011.
[7] Ala-eddin A. Saif, P. Poopalan, Effect of the Film Thickness on the
Impedance Behavior of Sol-gel Ba0.6Sr0.4TiO3 Thin Films," Physica b
condensed matter, vol. 406, pp. 1283-1288, 2011.
[8] Ala-eddin A. Saif, P. Poopalan, "Impedance/Modulus Analysis of Solgel
BaxSr1-xTiO3 Thin Films," J. Korean Phys. Soc. vol. 57, pp. 1449-
1455, 2010.
[9] R. Tripathi, A. Kumar, Ch. Bharti, T. P. Sinh, "Dielectric relaxation of
ZnO nanostructure synthesized by soft chemical method-, Curr. App.
Phys., vol. 10, pp. 676-681, 2010.
[10] M. A. Elkestawy, S. Abdelkader, M. A. Amer, "AC conductivity and
dielectric properties of Ti-doped CoCr1.2Fe0.8O4 spinel ferrite," Physica
B, vol. 405, pp. 619-624, 2010.
[11] G. Arlt, D. Hennings, G. De With, "Dielectric properties of
fineÔÇÉgrained barium titanate ceramics," J. Appl. Phys., vol. 58, pp.
1619-1625, 1985.
[12] S. H. Hu, G. J. Hu, X. J. Meng, G. S. Wang, J. L. Sun, S. L. Guo, J. H.
Chu, N. Dai, "The Grain Size Effect of the Pb(Zr0.45Ti0.55)O3 Thin
Films Deposited on LaNiO Coated Silicon by Modified Sol-gel
Process," J. Cryst. Growth, vol. 260, pp. 109-114, 2004.
[13] N. Kumari, S. B. Krupanidhi, K. B. R. Varma, "Dielectric, impedance
and ferroelectric characteristics of c-oriented bismuth vanadate films
grown by pulsed laser deposition" Mat. Sci. Eng. B, vol. 138, pp. 22-30,
2007.