[Zurück]

D. Dergez, M. Schneider, A. Bittner, U. Schmid:
"Mechanical and electrical properties of DC magnetron sputter deposited amorphous silicon nitride thin films";
Thin Solid Films, 589 (2015), S. 227 - 232.

Amorphous silicon nitride SiNx thin films in a thickness range of 40 to 500 nmwere deposited onto (100) silicon
wafers using DC magnetron sputtering. The biaxial stress of the films was found to be tuneable in the range of
−1300 MPa (compressive) to almost 0 by varying the plasma power density and the back pressure in the
deposition chamber. The films were close to stoichiometric composition with x ranging from 1.27 to 1.34. The
refractive index n decreases from 2.10 to 1.97 with increasing back pressure, indicating compositional changes
in the thin films. This finding, however,was not confirmed by Fourier-TransformInfrared Spectroscopymeasurements.
On the other hand, lower wet chemical etch rates revealed a larger robustness of layers deposited at
conditions where the mean kinetic energy of the sputtered particles is higher. Temperature dependent leakage
current measurements using Au/Cr/SiNx/Si MIS (metal-insulator-semiconductor) structures between 25
and 300 °C have shown that ohmic and Poole-Frenkel conduction mechanisms dominate the leakage current behaviour
at electrical fields ranging up to 0.5MV/cm. The extracted physical parameters such as the corresponding
activation energies were found to be mildly affected by the deposition parameters.

Amorphous silicon nitride SiNx thin films in a thickness range of 40 to 500 nmwere deposited onto (100) silicon
wafers using DC magnetron sputtering. The biaxial stress of the films was found to be tuneable in the range of
−1300 MPa (compressive) to almost 0 by varying the plasma power density and the back pressure in the
deposition chamber. The films were close to stoichiometric composition with x ranging from 1.27 to 1.34. The
refractive index n decreases from 2.10 to 1.97 with increasing back pressure, indicating compositional changes
in the thin films. This finding, however,was not confirmed by Fourier-TransformInfrared Spectroscopymeasurements.
On the other hand, lower wet chemical etch rates revealed a larger robustness of layers deposited at
conditions where the mean kinetic energy of the sputtered particles is higher. Temperature dependent leakage
current measurements using Au/Cr/SiNx/Si MIS (metal-insulator-semiconductor) structures between 25
and 300 °C have shown that ohmic and Poole-Frenkel conduction mechanisms dominate the leakage current behaviour
at electrical fields ranging up to 0.5MV/cm. The extracted physical parameters such as the corresponding
activation energies were found to be mildly affected by the deposition parameters.

DC reactive sputtering; Silicon nitride; Residual stress; Leakage current; Poole-Frenkel

http://dx.doi.org/10.1016/j.tsf.2015.05.028