Physical and electrical characterization of Hafnium oxide and Hafnium silicate sputtered films

• DOI: 10.1063/1.1417991
• Publication Date: 2002-07-26T12:01:09Z
• Authors: A. Callegari; E. Cartier; M. Gribelyuk; H. F. Okorn-Schmidt; T. Zabel
• Keywords: Hafnium; Forming gas; Equivalent oxide thickness; High-κ dielectric

Hafnium oxides and hafnium silicate films were investigated as a possible replacement for the SiO2 gate dielectric. oxide formed by reactive sputtering from single Hf target in predominantly Ar atmosphere containing small additions of oxygen. silicates made adding He-diluted silane gas Si incorporation. By changing flow, different atomic concentrations incorporated into films. Depositions performed with substrate held at temperatures 22 °C 500 °C. The chemical composition was determined nuclear techniques. Optical reflectivity used to measure optical band gap. film morphology transmission electron microscopy (TEM) electrical properties measured capacitance–voltage current–voltage measurements using aluminum capacitors. TEM measurement showed that interfacial layer about 3 nm interface due oxidizing sputter ambient. This precluded growth based high-K equivalent thickness. After correction layer, dielectric constant found decrease 21 4–5 low content (3 at. % 32 Si). gap increase 5.8 eV 7 annealing 1000 followed 300 postmetallization anneal, negligible flat voltage shift on good passivation observed. However, leakage currents increased high temperature processing.