Influence of frequency and bias voltage on dielectric properties and electrical conductivity of Al/TiO₂/p-Si/p⁺(MOS) structures

Abstract

In this study, the frequency and voltage dependence of the dielectric constant (ε′), dielectric loss (ε″), loss tangent (tan δ), electric modulus (M′ and M″) and ac electrical conductivity (σac) of Al/TiO2/p-Si (MOS) structures has been investigated using the capacitance–voltage (C–V) and conductance–voltage (G/ω–V) characteristics. A TiO2 thin film was deposited on the p-type Si substrate by using the sol–gel dip coating method. These C–V and G/ω–V characteristics were measured by applying a small ac signal of 50 mV amplitude in the frequency range 5 kHz–1 MHz, while the dc bias voltage was swept from (−4 V) to (4 V) at room temperature. Experimental results show that ε′, ε″, tan δ and σac are strongly frequency and voltage dependent. Accordingly, it has been found that as the frequency increases, ε′ and ε″ values decrease while an increase is observed in σac and the electric modulus. The results can be concluded to imply that the interfacial polarization can more easily occur at low frequencies consequently contributing to the deviation of dielectric properties and ac electrical conductivity of Al/TiO2/p-Si/p+ (MOS) structures.

On the profile of frequency dependent dielectric properties of (Ni/Au)/GaN/Al0.3Ga0.7N heterostructures

“…Generally, to extract as much information as possible, dielectric relaxation spectroscopy data are used in the electric modulus formalism [43]. Thus, the evaluation of the electric modulus as a function of frequency permits to detect the presence of relaxation processes in the studied materials [44]. In order to study dielectric dispersion in the (Ni/Au)/Al 0.3 Ga 0.7 N/ AlN/GaN heterostructures, we have used the complex electric modulus (M Ã ) as defined by following relation [23,[39][40][41][42] as, This dispersion is fairly clear in Fig.…”

Electric modulus based relaxation dynamics and ac conductivity scaling of polypyrrole nanotubes

“…The intercept and slope of the theoretically best fitted linear curve using Eq. (20) give value of the pre-exponential factor, s 0 = 1.48 Â 10 À2 S cm À1 and activation energy, E s = 0.21 eV, respectively. To correlate between the dc and ac conduction, the temperature dependence of hopping frequency is compared with that of the dc conductivity behavior as shown in Fig.…”

“…4(A) for each plot of M 0 , the value of M 0 increases with increasing frequency and reaches a maximum constant value ðM 1 ¼ 1=e 1 Þ at higher frequencies due to the relaxation process. However, value of M 0 approaches to zero at low frequencies suggesting that the electrode polarization gives negligible contribution to M 0 and hence it can be ignored when the permittivity data are expressed in this form [20]. On the other hand, each M 00 plot shows a well defined loss peak corresponding to a particular frequency called the relaxation frequency (v max ) at which charge carriers undergo the relaxation process.…”

Studies on Al/ZrO2/GaAs metal-oxide-semiconductor capacitors and determination of its electrical parameters in the frequency range of 10 kHz–1 MHz

“…The values of and ⌽ BO were determined to be 1.6 and 0.80 eV, respectively, at 290 K and 4.8 and 0.20 eV, respectively, at 80 K. These results are in consistent with the values reported in literature. [30][31][32] The variation in the ideality factor with the temperature can be explained using the Werner-Gütler potential fluctuation model. 30,31 According to this model, the ideality factor can be written as…”