Negative capacitance at metal-semiconductor interfaces

A negative capacitance effect has been observed in metal‐semiconductor contacts. This phenomenon is explained by considering the loss of interface charge at occupied states below Fermi level due to impact ionization. A modified Shockley–Read treatment is proposed to interpret the experimental observations. In particular, a two‐energy‐level simplified model is presented to simulate the capacitance spectrum. The results are in good agreement with the experimental data.