Current transport in metal/hafnium oxide/silicon structure

Abstract

Based on the experimental results of the temperature dependence of gate leakage current and Fowler-Nordheim tunneling characteristics at 77 K, we have extracted the energy band diagrams and current transport mechanisms for metal/HfO/sub 2//Si structures. In particular, we have obtained the following quantities that will be useful for modeling and simulation: i) HfO/sub 2//Si conduction band offset (or barrier height): 1.13 /spl plusmn/ 0.13 eV; ii) Pt/HfO/sub 2/ barrier height: /spl sim/ 2.48 eV; iii) Al/HfO/sub 2/ barrier height: /spl sim/ 1.28 eV; iv) electron effective mass in HfO/sub 2/: 0.1 m/sub o/, where m/sub o/ is the free electron mass and v) a trap level at 1.5 /spl plusmn/ 0.1 eV below the HfO/sub 2/ conduction band which contributes to Frenkel-Poole conduction.