Fabrication of Metal/Ferro-Electric/Semiconductor (Au/Bi4Ti3O12/n-Si) Devices and Temperature Dependent Examination of Their Complex Dielectric and Electric Modulus at 1 MHz

Abstract

Metal-semiconductor (MS) devices, which have ferroelectric (Bi4Ti3O12) interfacial layers, were fabricated and their complex dielectric and electric modules have been studied in a wide range of temperature (80-320 K) at 1 MHz. Our results revealed that these parameters and electrical conductivity were dependent on both the temperature and the voltage applied. The ε'-V and ε"-V plots have reverse bias, depletion and forward bias regions. Significant variations in ε’ and ε’’ characteristics have been observed especially in the depletion and forward bias regions. Variations in the depletion region were referred to the existence of states/traps (Dit) in the interfacial layer and effects of the temperature. In the case of the forward bias region, they were referred to the serial resistance (Rs) and the existence of the ferroelectric interfacial layer. ε'-V and ε"-V curves exhibited peak behavior in the depletion region. Such peak behavior was attributed to the special distributions of the interfacial states localized between (Bi4Ti3O12)/n-Si interface, the forbidden energy band of the semiconductor, temperature and electric field created by the applied dc voltage. Decreases in the ε', ε", M', M" and sigma values with respect to the decreasing temperature were referred to the non-existence of the sufficient free carriers at lower temperature and to the high amount of charge transfers from traps to the conduction band as temperature increases.

Keywords

• MFS structure
• Dielectric parameters
• Electric modulus