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D. Dergez, M. Schneider, A. Bittner, N. Pawlak, U. Schmid:
"Mechanical and electrical properties of RF magnetron sputter deposited amorphous silicon-rich silicon nitride thin films";
Thin Solid Films, 606 (2016), 7 - 12.

Amorphous silicon nitride thin films in a thickness range of 40 to 500 nmare deposited onto (100) siliconwafers
using radio frequency magnetron sputter deposition. Analysis of variance techniques are used to determine
which deposition parameter has a significant impact on the film properties. The biaxial stress of the layers is
found to be compressive independent of the plasma chamber pressure levels and to increase with increasing
plasma power. The chemical composition of the films is silicon-rich, resulting in an index of refraction (IOR) of
2.55 independent of deposition conditions. Both IOR and X-ray photoelectron spectroscopy measurements indicate
a nitrogen to silicon ratio in the range of 0.71-0.85. The etch rates for HFwet chemical etching and for CF4:O2
reactive ion etching are found to be much higher compared to direct current sputter deposited silicon nitride
films with only a weak dependency on the deposition conditions. Temperature dependent leakage current measurements
using Au/Cr/SiNx/Si structures between 25 and 300 °C show two dominating leakage currentmechanisms:
ohmic conduction dominates at lowapplied electric field values below0.1MV/cmand Poole-Frenkel type
conduction above 0.3 MV/cm. The extracted electrical parameters such as the activation energy or the barrier
height are found to be nearly unaffected by the deposition parameters.

Amorphous silicon nitride thin films in a thickness range of 40 to 500 nmare deposited onto (100) siliconwafers
using radio frequency magnetron sputter deposition. Analysis of variance techniques are used to determine
which deposition parameter has a significant impact on the film properties. The biaxial stress of the layers is
found to be compressive independent of the plasma chamber pressure levels and to increase with increasing
plasma power. The chemical composition of the films is silicon-rich, resulting in an index of refraction (IOR) of
2.55 independent of deposition conditions. Both IOR and X-ray photoelectron spectroscopy measurements indicate
a nitrogen to silicon ratio in the range of 0.71-0.85. The etch rates for HFwet chemical etching and for CF4:O2
reactive ion etching are found to be much higher compared to direct current sputter deposited silicon nitride
films with only a weak dependency on the deposition conditions. Temperature dependent leakage current measurements
using Au/Cr/SiNx/Si structures between 25 and 300 °C show two dominating leakage currentmechanisms:
ohmic conduction dominates at lowapplied electric field values below0.1MV/cmand Poole-Frenkel type
conduction above 0.3 MV/cm. The extracted electrical parameters such as the activation energy or the barrier
height are found to be nearly unaffected by the deposition parameters.

RF reactive sputtering Silicon nitride Residual stress Etching behaviour Leakage current Poole-Frenkel

http://dx.doi.org/10.1016/j.tsf.2016.03.029