Analysis of the electrical characteristics of Zn/ZnSe/n-Si/Au–Sb structure fabricated using SILAR method as a function of temperature

Abstract

The Successive Ionic Layer Adsorption and Reaction (SILAR) method has been used to deposit ZnSe thin film onto Si substrate to obtain the Zn/ZnSe/n-Si/Au–Sb sandwich structure. The X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) methods are used to investigate the structural and morphological properties of films. The XRD and SEM studies reveal that the films are covered well on Si substrate and have good polycrystalline structure and crystalline levels. The current–voltage ( I– V) and capacitance–voltage ( C– V) characteristics of this structure have been investigated as a function of the temperature (80–300 K) with 20 K steps. The ideality factor ( n) and zero-bias barrier height ( Φ b0 ) value which obtained from I– V curves were found to be strongly temperature dependent. While Φ b0 increases with increasing temperature, n decreases. This behavior of the Φ b0 and n can be attributed to barrier inhomogeneities at the metal–semiconductor ( M– S) interface. The temperature dependence of the I– V characteristics of the Zn/ZnSe/n-Si/Au–Sb structure can reveal the existence of a double Gaussian distribution. The mean barrier height and the Richardson constant values are obtained as 0.925 eV and 1.140 eV, 130 A/cm 2 K 2 and 127 A/cm 2 K 2, from the modified Richardson plot, respectively. Furthermore, the barrier height and carrier concentration are calculated from reverse bias C −2– V measurements at 200 kHz frequency as a function of the temperature.