AbstractTo the best of our knowledge. The current work shows that negative capacitance exists at all frequencies, contrary to what is claimed in the literature, which states that negative capacitance only exists at high or low frequencies. In this paper, Au/AlCu/SiO2/p-Si/Al structure was epitaxial grown by the liquid phase epitaxial growth technique. The structural characterization was studied using an X-ray diffraction pattern. The capacitance and conductance behavior was studied using I-V and C-V measurements at various temperatures, voltages, and frequencies. Negative capacitance appears at all frequencies ranging from low to high; moreover, capacitance has both positive and negative values at all frequencies, while the conductance has positive values only in all frequencies. The current-voltage characterization was used to investigation the ideality factor, barrier height, and series resistance. The barrier height and Richard constant were estimated, through investigating the current conduction mechanism of Au/AlCu/SiO2/p-Si/Al.