Effects of Frequency and Bias Voltage on Dielectric Properties and Electric Modulus of Au/Bi4Ti3O12/n-Si (MFS) Capacitors

Yıl 2017, Cilt: 20 Sayı: 4, 1003 - 1008, 20.12.2017

Perihan Durmuş Çiğdem Bilkan Mert Yıldırım

https://doi.org/10.2339/politeknik.369147

Cited By: 1

Öz

In this work, a metal-ferroelectric-semiconductor (MFS) type capacitor
was fabricated and admittance measurements were held in a wide frequency range
of 1 kHz-5 MHz at room temperature for the investigation of frequency and
voltage dependence of complex dielectric constant, complex electric modulus and
electrical conductivity of the MFS
capacitor. Bismuth titanate (Bi₄Ti₃O₁₂) with high dielectric constant was used as
interfacial ferroelectric material and the structure of MFS capacitor was
obtained as Au/Bi₄Ti₃O₁₂/n-Si. Experimental
results showed that dielectric, modulus and conductivity parameters are strong
functions of frequency and voltage especially in depletion and accumulation
regions due to the existence of surface states (N_ss), series
resistance (R_s), interfacial polarization and interfacial layer. It
was found that R_s of the structure and interfacial ferroelectric
layer are efective in accumulation region whereas surface states (N_ss)
and interfacial polarization are efective in
depletion region. Also the changes in dielectric, modulus and conductivity
parameters become considerably high particularly at low frequencies due to high
values of R_s and N_ss. The observed anomalous peak in voltage dependent plots of
capacitance and dielectric constant was atributed to the particular density
distribution of N_ss, R_s and minority carrier injection.
Moreover, the value of conductivity
at low and intermediate frequencies is almost independent of frequency thus low
frequency data was used to extract d.c. conductivity. This work showed that the use of high-dielectric Bi₄Ti₃O₁₂
as ferroelectric interfacial layer in a MFS capacitor is preferable due to high
values of its dielectric constant compared with traditional insulator layer
materials such as SiO₂ and SnO₂. Therefore, a MFS
capacitor with Bi₄Ti₃O₁₂ interfacial layer can
store more energy thanks to its high dielectric constant.

Anahtar Kelimeler

MFS capacitors, frequency and voltage dependence, surface states and interfacial polarization, dielectric properties and electrical modulus

Kaynakça

• [1] Asar Y. Ş., Asar T., Altındal Ş. and Özçelik S., “Dielectric spectroscopy studies and ac electrical conductivity on (AuZn)/TiO2/p-GaAs (110) MIS structures”, Philosophical Magazine, 95: 2885-2898, (2015). [2] Asar Y. Ş., Asar T., Altındal Ş. and Özçelik S., “Investigation of dielectric relaxation and ac electrical conductivity using impedance spectroscopy method in (AuZn)/TiO2/p-GaAs (110) schottky barrier diodes” Journal of Alloys and Compounds, 628: 442-449, (2015). [3] Tanrıkulu E. E., Yıldız D. E., Günen A. and Altındal Ş., “Frequency and voltage dependence of electric and dielectric properties of Au/TiO2/n-4H-SiC (metal-insulator-semiconductor) type Schottky barrier diodes”, Physica Scripta, 90: 095801, (2015). [4] Yıldırım M., Durmuş P. and Altındal Ş., “Analyses of temperature-dependent interface states, series resistances, and AC electrical conductivities of Al/p-Si and Al/Bi4Ti3O12/p-Si structures by using the admittance spectroscopy method”, Chinese Physics B, 22: 108502, (2013). [5] Durmuş P. and Yıldırım M., “Influence of interfacial layer thickness on frequency dependent dielectric properties and electrical conductivity in Al/Bi4Ti3O12/p-Si structures”, Journal of Vacuum Science and Technology, 32: 061512 (2014). [6] Reddy V. R., Manjunath V., Janardhanam V., Kil Y. H. and Choi C. J., “Electrical Properties and Current Transport Mechanisms of the Au/n-GaN Schottky Structure with Solution-Processed High-k BaTiO3 Interlayer”, Journal of Electronic Materials, 43: 3499-3507 (2014). [7] Kaya A., Alialy S., Demirezen S., Balbaşı M., Yerişkin S. A. and Aytimur A., “The investigation of dielectric properties and ac conductivity of Au/GO-doped PrBaCoO nanoceramic/n-Si capacitors using impedance spectroscopy method”, Ceramics International, 42: 3322-3329, (2016). [8] Yerişkin S. A., Balbaşı M. and Tataroğlu A., “Frequency and voltage dependence of dielectric properties, complex electric modulus, and electrical conductivity in Au/7% graphene doped-PVA/n-Si (MPS) structures”, Journal of Applied Polymer Science, 133: 43827, (2016). [9] Chu L. K., Chiang T. H., Lin T. D., Lee Y. J., Chu R. L., Kwo J. and Hong M., “Ge metal-oxide-semiconductor devices with Al2O3/Ga2O3(Gd2O3) as gate dielectric”, Microelectronic Engineering, 91: 89-92 (2012). [10] Yıldırım M., “Current conduction and steady-state photoconductivity in photodiodes with bismuth titanate interlayer”, Thin Solid Films, 615: 300-304, (2016). [11] Jayalakshmi M. and Balasubramanian K., “Simple Capacitors to Supercapacitors - An Overview”, International Journal of Electrochemical Science, 3: 1196-1217, (2008). [12] Sze S. M., “Physics of Semiconductor Devices”, Wiley, New York, (1985). [13] Rhoderick E. H., “Metal-Semiconductor Contacts”, Oxford University Press, Oxford, (1978). [14] Altındal Ş., Kanbur H., Tataroğlu A. and Bülbül M. M., “The barrier height distribution in identically prepared Al/p-Si Schottky diodes with the native interfacial insulator layer (SiO2)”, Physica B, 399: 146-154, (2007). [15] Chattopadhyay P. and Raychaudhuri B., “Origin of the anomalous peak in the forward capacitance-voltage plot of a Schottky barrier diode”, Solid-State Electronics, 35: 875-878, (1992). [16] Lee, H. N., Kim, Y. T. and Choh, S. H. “Comparison of memory effect between YMnO3 and SrBi2Ta2O9 ferroelectric thin films deposited on Si substrates”, Applied Physics Letters, 76: 1066-1068, (2000). [17] Fujisaki Y., Kijima T. and Choh S. H., “High-performance metal-ferroelectric-insulator-semiconductor structures with a damage-free and hydrogen-free silicon–nitride buffer layer”, Applied Physics Letters, 78: 1285-1287, (2001). [18] Lee S. K., Kim Y. T., Kim S. I. and Lee C. E., “Effects of coercive voltage and charge injection on memory windows of metal-ferroelectric-semiconductor and metal-ferroelectric-insulator-semiconductor gate structures”, Journal of Applied Physics, 91: 9303-9307, (2002). [19] Altındal, Ş., Parlaktürk F., Tataroglu A. and Bülbül M. M., “Temperature and frequency dependent dielectric properties of Au/Bi4Ti3O12/SiO2/Si (MFIS) structures”, Journal of Optoelectronics and Advanced Materials, 12: 2139-2144, (2010). [20] Card H. C. and Rhoderick E. H., “Studies of tunnel MOS diodes I. Interface effects in silicon Schottky diodes”, Journal of Physics D: Applied Physics, 4: 1589, (1971). [21] Nicollian E. H. and Brews J. R., “MOS Physics and Technology”, Wiley, New York, (1982). [22] Reddy M. S. P., Kang H. S., Lee J. H., Reddy V. R. and Jang J. S., “Electrical properties and the role of inhomogeneities at the polyvinyl alcohol/n-inp schottky barrier interface”, Journal of Applied Polymer Science, 131: 39773, (2014). [23] Reddy, V. R., Janardhanam, V., Leem, C. H. and Choi, C. J., “Electrical properties and the double Gaussian distribution of inhomogeneous barrier heights in Se/n-GaN Schottky barrier diode”, Superlattices and Microstructures, 67: 242-255, (2014). [24] Sharma B. L., “Metal-Semiconductor Schottky Barrier Junctions and Their Applications”, Springer Science & Business Media, (2013). [25] Fonash S. J., “A reevaluation of the meaning of capacitance plots for Schottky barrier type diodes”, Journal of Applied Physics, 54: 1966-1975, (1983).