Gate-Controllable Electronic Trap Detection in Dielectrics

Abstract

Gate controllable electronic trap detection method has been demonstrated by regulating the gate potential of MIS devices. This method is based on shift of capacitance–voltage (CV) curve as well as flatband voltage ( $\text{V}_{\text{FB}}$ ) measure in $ due to injection or ejection of electrons through the metal gate. Using this method, an electronic trap energy distribution was measured in the HfO2 dielectric film and it confirms a maximum number of traps ( $\Delta \text{N}_{\text{T}}$ ) of $1.7\times 10^{12}$ cm $^{-2}$ corresponding to an energy level ( $\Delta \text{E}_{\text{IL}}$ ) of 0.45 eV above silicon conduction band (Si- $\text{E}_{\text {CB}}$ ). In comparison, ZrO2-based MIS devices showed a broader distribution of electronic traps throughout the band gap. However, HfO2 contained more than 60% traps in deep level compared to 50% in ZrO2, which establishes the effects of material variation.