Electron Trap Energy Distribution in HfO₂ by the Discharge-Based Pulse I–V Technique

The electron traps in HfO₂ are a major concern of the reliability of metal-oxide-semiconductor field effect transistors (MOSFETs) beyond the 30 nm technology generation. In this work, the principle of the discharge-based pulse I–V technique is demonstrated in detail. By using this technique, the thorough energy distribution of electron traps across the 4 nm HfO₂ layer is identified, which overcomes the shortcomings of the current techniques. It is observed that there are two peaks in HfO₂. The large peak is at around 1.0 eV below the HfO₂ conduction band bottom. The small peak is at about 1.43 eV below the HfO₂ conduction band bottom. The results provide valuable information for theoretical modeling establishment, fast material assessment and process optimization for MOSFETs with high-k gate dielectrics.