Determination of physical parameters for HfO2/SiOx/TiN MOSFET gate stacks by electrical characterization and reverse modeling

In this paper we present the results of a combined electrical and modeling study to determine the tunneling electron effective mass and electron affinity for HfO₂. Experimental capacitance-voltage (C-V) and current-voltage (I-V) characteristics are presented for HfO₂ films deposited on Si(100) substrates by atomic layer deposition (ALD) and electron beam evaporation (e-beam), with equivalent oxide thickness in the range 10 and 12.5A. We extend on previous studies by applying a self-consistent 1D- Schrodinger-Poisson solver to the entire gate stack, including the inter-layer SiO_x region and to the adjacent substrate for non-local barrier tunneling self- consistently linked to the quantum-drift-diffusion transport model. The reverse modeling is applied to the correlated gate and drain currents in long channel MOSFET structures. Values of 0.11 + (0.03) m_o and 2.0 + (0.25) eV were determined for the HfO₂ electron effective mass and electron affinity.