AVS 45th International Symposium
    Plasma Science and Technology Division Thursday Sessions
       Session PS-ThA

Paper PS-ThA8
Volume/Surface Effects on Dissociation Processes in Ar/C@sub 4@F@sub 8@ Plasma

Thursday, November 5, 1998, 4:20 pm, Room 318/319/320

Session: Diagnostics II
Presenter: K. Kinoshita, Association of Super-Advanced Electronics Technologies (ASET), Japan
Authors: K. Kinoshita, Association of Super-Advanced Electronics Technologies (ASET), Japan
S. Morishita, ASET, Japan
S. Noda, ASET, Japan
M. Okigawa, ASET, Japan
M. Inoue, ASET, Japan
M. Sekine, ASET, Japan
Correspondent: Click to Email
We clarified that the control of multistage dissociation in Ar diluted C@sub 4@F@sub 8@ plasma via the total number of collisions, @tau@ N@sub e@ <@sigma@v>,@footnote 1@ is essential in establishing a high-performance SiO@sub 2@ etch process in a narrow-gap parallel plate reactor. For the scaling of the reactor to a larger wafer size in the near future, a wider gap space will be required to assure uniformity of the gas supply and exhaust. Changing the gap space (i.e, volume/surface ratio) must affect the gas dissociation process by changing total number of collisions. Here, @tau@ and N@sub e@ can be controlled by the pumping speed and source power. Therefore, we examined the change in <@sigma@v> on the gap space and its effect on the dissociation process. Two kinds of UHF (500 MHz) plasma sources were used. One source had a spoke antenna coupled with plasma through a quartz top plate and the other had a carbon top plate antenna with a magnetic field of ECR condition. In both systems, when the gap space was widened, the N@sub e@ increased and <@sigma@v> for the C@sub 4@F@sub 8@ dissociation decreased, when @tau@ was constant. <@sigma@v> for excitation for ArI emission also decreased with increasing gap space. Kinetic analysis through rate equations indicated that the reaction rate constant <@sigma@v> for the F generation reaction decreased with increase in gap space in both plasma sources. These results suggest that changing the electron energy distribution by changing the gap space significantly influences the reaction rate constant of the dissociation reactions in the Ar/C@sub 4@F@sub 8@ plasma. @FootnoteText@ This work was supported by NEDO. @footnote 1@ T. Tatsumi et al., Jpn. J. Appl. Phys., 37 (1998) to be published