Current transport mechanisms in metal – high-k dielectric – silicon structures

Abstract

Abstract. The mechanism of current transport in several high k  -dielectric, including rare earth metal oxides (Gd 2 O 3 , Nd 2 O 3 ), ternary compounds (LaLuO 3 ) and rare earth metal silicate (LaSiO x ) thin films on silicon was studied using current-voltage ( V I  ) and conductance-frequency (   G  ) measurements at temperatures 100-300 K. It was shown that the current through the dielectric layer is controlled either by Pool-Frenkel mechanism of trap-assisted tunneling or by Mott's variable range hopping conductance through the localized states near the Fermi level. From the results of measurements, the dynamic dielectric constant k of the material, energy positions and bulk concentrations of traps inside the dielectric layers were determined.

Novel high-k dielectrics for nanoelectronics

“…44showed that there is no additional undesirable interfacial layer between Gdsilicate and silicon even for samples annealed up to 800°C. This is due to the small lattice mismatch as well as presence of Si atoms in Gd-silicate as mentioned which helped in preventing the IL formation[100].XPS of Si 2p peaks comparison for CeO 2 /TiO 2 and CeO 2 /GdSiO(Fig. 45) sample had further confirmed the presence of interfacial layer formation which matches well with our TEM and electrical data.…”

Charge Trapping in Hafnium Silicate Films with Modulated Composition and Enhanced Permittivity

“…Although pure HfO 2 tends to transform from amorphous to crystalline structure upon fabrication and/or post-fabrication processing [2,9], the formation of the tetragonal HfO 2 phase is the most preferable due to its higher k value (up to 70) and lower free energy in comparison with those of the monoclinic HfO 2 phase (k=16-18) [12,13]. It was also demonstrated that interface state densities can be reached as low as D it =(1.5-2.0)×10 11 eV -1 •cm -2 for Hf-based dielectrics grown on (100) Si substrate [1,14]. However, the formation of thick SiO 2 interfacial layer, separating the HfO 2 film from the Si substrate, is still an issue for HfO 2 applications [1,2,15].…”