The investigation of temperature dependence current transmission mechanism of Au/4H n-SiC schottky diodes

The current-voltage (I-V) characteristics of Au/4H n-SiC metal-semiconductor (MY) structures/Schottky diodes were measured in the temperature range of 80-300 K. It was observed thatideality factor (n)andthe zero-barrier height (ΦBo)obtained from the I-V characteristicswere temperature dependent. The formation of two linear regions in the ΦBo-n plot of the Au /4H n-SiC MY Schottky diode were attributed to the Schottky barrier inhomogeneity at the Au /4H n-SiC interface. The ΦBo-q/2kT graph was plotted to provide evidence that barrier inhomogeneity of Au /4H n-SiC interface shows a double Gaussian distribution (GD). The mean barrier heights and the standard deviationsfrom the two linear regions in this plot were determined as Φ̄B01 = 1.224 eV , Φ̄B02=0.58 eV, and σo1= 0.15 V σo2= 0.07 V, respectivly. Similarly, two linear regions were seen in the modified ln(Io/T2)-q2σo2/2k2T2]-q/kT plot. According[ln(Io/T2)-q2σo2/2k2T2]-q/kT plot, Φ̄B01andΦ̄B02values areobtained as 0.51 eV and 1.22 eV,respectively, Richardson's constant A1*and A2*values areobtained as 450 Acm-2K-2 ve 147 Acm-2K-2respectively.The experimentally determined Richardson constant value was found to be quite close to the theoretical value of 146 AK-2cm-2 of 4H n-SiC. As a result, it was seen that the temperature dependence of the I-V characteristics of Au/4H n-SiC Schottky diodes can be successfully explained by the TE mechanism basis double GD. Then, in order to show the inhomogeneous barrier height formed at the Au /4H n-SiC MY interface is in a double Gaussian distribution, theoretically double Guassian P(∅)-∅pa function obtained using ρ1=4.84×10-4, ∅1=1.203 eV, ∅2=0.571 eV, σ1=144.5 meV and 𝜎𝜎2=70 meV parameters.Thus, it was seen theoretically and experimentally that the dominant current-conducting mechanism in Au/4H n-SiC diodes can be successfully explained by TE-based double GD.In addition, reverse-bias JR-V characteristics of Au/4H n-SiC Schottky diodes were investigated in the temperature range of 80-300 K. The Poole-Frenkel emission associated with the interface traps was dominant in the reverse-bias conduction and barrier height emission (Φt) and relative dielectric constant (εs) were calculated from the S(T)-1/T and R(T)-1/T plots for 4H n- SiC MY Schottky diodes.