1887
banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
Comparison of methods to determine bandgaps of ultrathin HfO2 films using spectroscopic ellipsometry
Rent:
Rent this article for
USD
10.1116/1.3597838
/content/avs/journal/jvsta/29/4/10.1116/1.3597838
http://aip.metastore.ingenta.com/content/avs/journal/jvsta/29/4/10.1116/1.3597838

Figures

Image of FIG. 1.
FIG. 1.

Band alignment of HfO2/SiO2/Si stack. CB: conduction band; VB: valence band; CBO: conduction band offset between HfO2 and Si; VBO: valence band offset between HfO2 and Si, Eg : bandgap.

Image of FIG. 2.
FIG. 2.

Tauc-Lorentz model of the imaginary part of the dielectric function for HfO2. Eg : bandgap; E 0: peak energy for Lorentz oscillator, A: oscillator strength; C: oscillator width. Details are discussed in the text.

Image of FIG. 3.
FIG. 3.

Cody-Lorentz model of the imaginary part of the dielectric function for HfO2. Eg : bandgap; E 0: peak energy for Lorentz oscillator; A: oscillator strength; Γ: oscillator width; Ep : transition energy; Eu determines how fast Urbach tail decreases; Et determines where Urbach tail starts. Details are discussed in the text.

Image of FIG. 4.
FIG. 4.

Experimental and theoretical Ψ and Δ curves from (40 Å) HfO2/(12 Å) SiO2/Si.

Image of FIG. 5.
FIG. 5.

Extinction coefficient (k) of a 40 Å HfO2 film. CL: Cody-Lorentz model; PPF: point by point fitting; TL: Tauc-Lorentz model.

Image of FIG. 6.
FIG. 6.

Bandgap linear fit extrapolation using extinction coefficient k for 40 Å HfO2 film (Eg = 5.94 ± 0.02 eV).

Image of FIG. 7.
FIG. 7.

Bandgap linear fit extrapolation using the imaginary part of dielectric function ε2 for 40 Å HfO2 film (Eg = 5.91 ± 0.02 eV).

Image of FIG. 8.
FIG. 8.

Bandgap linear fit extrapolation using the absorption coefficient α for 40 Å HfO2 film (Eg  = 6.04 ± 0.03 eV).

Image of FIG. 9.
FIG. 9.

Bandgap extrapolation using the Tauc method for 40 Å HfO2 film (Eg  = 5.48 ± 0.02 eV).

Image of FIG. 10.
FIG. 10.

Bandgap extrapolation using the Cody method for 40 Å HfO2 film (Eg  = 5.36 ± 0.01 eV).

Image of FIG. 11.
FIG. 11.

Extinction coefficients k of HfO2 films from PPF for various thicknesses.

Image of FIG. 12.
FIG. 12.

Log plot of extinction coefficient k vs photon energy.

Tables

Generic image for table
TABLE I.

Bandgap values (eV) determined from different methods for HfO2 films.

Loading

Article metrics loading...

/content/avs/journal/jvsta/29/4/10.1116/1.3597838
2011-06-23
2014-04-20
Loading

Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: Comparison of methods to determine bandgaps of ultrathin HfO2 films using spectroscopic ellipsometry
http://aip.metastore.ingenta.com/content/avs/journal/jvsta/29/4/10.1116/1.3597838
10.1116/1.3597838
SEARCH_EXPAND_ITEM