Grazing incidence-X-ray fluorescence spectrometry for the compositional analysis of nanometer-thin high-kappa dielectric HfO2 layers.
In future microelectronic devices, SiO2 as a gate dielectric material will be replaced by materials with a higher dielectric constant. One such candidate material is HfO2. Thin layers are typically deposited from ligand-containing precursors in chemical vapor deposition (CVD) processes. In the atomic layer deposition (ALD) of HfO2, these precursors are often HfCl4 and H2O. Obviously, the material properties of the deposited films will be affected by residual ligands from the precursors. In this paper, we evaluate the use of grazing incidence--and total reflection-X-ray fluorescence spectrometry (GI-XRF and TXRF) for Cl trace analysis in nanometer-thin HfO2 films deposited using ALD. First, the results from different X-ray analysis approaches for the determination of Hf coverage are compared with the results from Rutherford backscattering spectrometry (RBS). Next, we discuss the selection of an appropriate X-ray excitation source for the analysis of traces within the high-kappa: layers. Finally, we combine both in a study on the accuracy of Cl determinations in HfO2 layers.
Hellin
David
D
Interuniversity Micro Electronics Center, Kapeldreef 75, B-3001 Leuven, Belgium. David.Hellin@imec.be
Delabie
Annelies
A
Puurunen
Riikka L
RL
Beaven
Peter
P
Conard
Thierry
T
Brijs
Bert
B
De Gendt
Stefan
S
Vinckier
Chris
C