| AVS 56th International Symposium & Exhibition | |
| Plasma Science and Technology | Wednesday Sessions |
| Session PS2+TF-WeM |
| Session: | Plasma Deposition and Plasma-assisted ALD |
| Presenter: | F. Henry, Université Libre de Bruxelles, Belgium |
| Authors: | F. Henry, Université Libre de Bruxelles, Belgium A. Batan, Université Libre de Bruxelles, Belgium F. Reniers, Université Libre de Bruxelles, Belgium |
| Correspondent: | Click to Email |
The reactive magnetron sputtering technique is widely used for thin films deposition. This one offers many advantages like: a large choice of composition of the deposited films, a low temperature of deposition that allows to use a large scale of substrates and a high speed of deposition. Other techniques used for thin films deposition like CVD often required the use of hazardous gases and required a high temperature of deposition.
In this study, two different gas mixtures (Ar/NH3 and Ar/H2/N2) used for the deposition of silicon nitride thin films were compared. Optical Emission spectroscopy spectrum (OES) were recorded to characterize the plasma gas phase. X-ray Photon-electron Spectroscopy (XPS) was used to determine the stoichiometry of the deposited thin films and used to perform a depth profiling of the silicon target after exposure to the reactive magnetron sputtering discharge. Optical interferometry was used to measure the film thickness and current-voltage curves were plotted to determine the electric characteristics of the discharge.
The influence of the plasma parameters such as the molar fraction of reactive gas and the total pressure was studied. The same parameters were investigated for both kind of gas mixture and a detailed comparison was performed.
The experiments were performed in a stainless steel chamber equipped with a home-made magnetron cathode. The total pressure was set between 5 x 10-3 Torr and 2 x 10-2 Torr and the molar fraction varied between 0 and 0.6 in reactive gas. During all experiments the discharge current was set to 300 mA.
The excited species detected into the Ar/NH3 and Ar/H2/N2 plasma were the same, except for the NH radical that was not detected in the Ar/H2/N2 plasma.
The stoichiometry of the thin films deposited with the two kind of gas mixtures was investigated by XPS, a N/Si ratio of 1.33 was determined for the Ar/H2/N2 plasma and 1.22 for the Ar/NH3 plasma.
The current voltage curves were plotted at different molar fractions of reactive gas and at different total pressures. A typical drop of the tension due to a poisoning of the target was observed for the Ar/NH3 plasma and for the Ar/H2/N2.