Characteristics of leakage current mechanisms and SILC effects of HfO2 gate dielectric

HfO2 gate dielectric thin films are deposited on p-Si(100) substrates by the method of reacting magnetron sputtering and furnace annealing. Analysis of leakage current conduction mechanisms of HfO2 gate dielectric films shows that the leakage is induced mainly by Schottky emission mechanism for substrate electron injection, while both Schottky emission and Frenkel-Poole emission mechanism may contribute to the leakage current for gate electron injection. As to SILC, in the fresh devices there exist few interfacial traps at HfO2/Si interface. However, negative gate bias stress can cause the generation of new inter-facial traps at HfO2/Si interface. With the increase of new interfacial traps, the leakage current conduction mechanisms of HfO2 gate dielectric films are induced by not only Schottky emission but also Frenkel-Poole emission. It also can be found that area dependence of SILC effects is very small.