In this work, we investigated and compared the difference in temperature dependence of ideality values, barrier heights, and series resistances obtained using current-voltage (I-V) characteristics from various methods for Cu/n-type Si structures in the temperature range of 50 K-310 K by 20 K steps. From the I-V measurements using Cheung's and Norde methods, the temperature-dependent changes of ideality factors (n), barrier heights (phi(b)), and sequence resistances (R-S) were obtained. The experimental findings showed that all the values obtained from the Cu/n-type Si structure of the main parameters (n, phi(b), and R-S) decreased with increasing temperature, and that these values were also in strong agreement with each other. In addition, the interface states (N-SS) were derived from the current-voltage characteristics as a function of temperature (K), and the experiment revealed that with increasing temperature, the interface states decreased. The interface states values for 50 K and 310 K of the Cu/n-type Si structure changed to be 8.10 x 10(11) eV(-1) cm(-2) and 2.72 x 10(11) eV(-1) cm(-2), respectively.