AVS 51st International Symposium
    Thin Films Wednesday Sessions
       Session TF-WeM

Paper TF-WeM9
Analysis of a Combined Sputtering and Plasma-Heating-Evaporation Process of Magnesium Fluoride by using Plasma Emission Spectroscopy and Energy Resolved Type Mass Spectrometry

Wednesday, November 17, 2004, 11:00 am, Room 303C

Session: Optical Thin Films
Presenter: T. Deguchi, Kanazawa Institute of Technology, Japan
Authors: T. Deguchi, Kanazawa Institute of Technology, Japan
T. Sasaki, Kanazawa Institute of Technology, Japan
E. Kusano, Kanazawa Institute of Technology, Japan
S. Iura, Olympus Co., Ltd., Japan
K. Kawamata, Olympus Co., Ltd., Japan
A. Kinbara, Kanazawa Institute of Technology, Japan
Correspondent: Click to Email
A sputtering deposition process combined with plasma-heating-evaporation is an attractive technique to deposit MaF@sub 2@ thin films onto unheated substrate. However, poor understandings of the mechanisms prevent stabilization of the process. In this study, we have analyzed the process by using plasma emission spectroscopy and energy resolved type mass spectrometry. A sputtering machine used for mass spectrometry was a UHV system equipped with a 55 mm diameter cathode and that for film deposition and plasma emission spectroscopy was a commercial batch type system equipped with a 75 mm diameter cathode. The plasma process monitor (PPM-421, Balzers AG) was used to analyze a mass/charge ratio and energy of ions arriving to the substrate. A spectrometer (TYPE HR-2000, Ocean Optics) was used for plasma emission spectroscopy. Ions typically detected were Mg@super +@, F@super +@, MgF@super +@ both in Ar and O@sub 2@ atmospheres. While in Ar atmosphere the number of MgF@super +@ decreased with increasing rf plasma power, in O@sub 2@ atmosphere it increased drastically after the plasma power exceeded 250W. At this point in O@sub 2@ atmosphere the plasma-heating-evaporation occurred. Results obtained by the plasma emission spectroscopy well agreed to these results; i.e., the emission intensity ratio MgF@super *@/O@super *@ increased significantly at an rf power of 200W. Furthermore, the high energy tail in ion energy spectra, resulting from momentum transfer in sputtering process, observed for Mg@super +@ or F@super +@ in Ar atmosphere disappeared for those in O@SUB 2@ atmosphere, showing that the evaporation process in O@sub 2@ atmosphere was not dominated by sputtering, but by thermal evaporation.