AVS 52nd International Symposium
    Plasma Science and Technology Thursday Sessions
       Session PS-ThA

Paper PS-ThA6
Independent Control of Backscattering Energy and Sputter Rate in a VHF-DC Superimposed Magnetron Source

Thursday, November 3, 2005, 3:40 pm, Room 304

Session: Plasma Sources and Equipment
Presenter: H. Toyoda, Nagoya University, Japan
Authors: H. Toyoda, Nagoya University, Japan
Y. Sakashita, Nagoya University, Japan
Y. Takagi, Nagoya University, Japan
K. Sasaki, Nagoya University, Japan
J. Gao, Nagoya University, Japan
T. Kato, Nagoya University, Japan
S. Iwata, Nagoya University, Japan
S. Tsunashima, Nagoya University, Japan
H. Sugai, Nagoya University, Japan
Correspondent: Click to Email
Recent application of magnetron plasma to nano-scale thin film deposition requires damage-free atomic-scale flat surfaces of the deposited film. In general, surface qualities of sputter deposited films are influenced by the incidence of particles with high kinetic energies. Thus, control of energetic ions and neutrals impinging on substrate is an important issue, in order to clarify a correlation between energetic particles and film qualities. In the magnetron discharge in argon gas, a significant amount of energetic Ar atoms is backscattered from the target surface and incident on the substrate. The backscattering energy can be reduced by lowering the target voltage, but it results in a decrease in the sputter deposition rate. In this study, we present independent control of the backscattering energy and the sputter deposition rate by superimposing VHF and DC voltage to the target. Discharge characteristic and sputter deposition rate are investigated by a Langmuir probe, a quadrupole mass spectrometer (QMS) with an energy analyzer and a quartz crystal microbalance. From the QMS measurement of energetic Ar ions, a decrease in the energy of backscattered Ar atoms is inferred. It is confirmed that the sputter deposition rate of the VHF-DC superimposed magnetron discharge at lower target DC voltage (~100 V) is almost comparable to that of the conventional DC magnetron discharge at higher target voltages (>400 V).