AVS 47th International Symposium
    Plasma Science and Technology Tuesday Sessions
       Session PS2-TuA

Paper PS2-TuA8
Temperature and Distance Dependencies of Fluorocarbon Species Desorbed from Polymer Deposited Metal Surface in C@sub 4@F@sub 8@ Inductively Coupled Plasma

Tuesday, October 3, 2000, 4:20 pm, Room 311

Session: Plasma Diagnostics I
Presenter: H.-H. Doh, University of Tokyo, Japan
Authors: H.-H. Doh, University of Tokyo, Japan
T. Ichiki, Toyo University, Japan
Y. Tezuka, University of Tokyo, Japan
Y. Horiike, University of Tokyo, Japan
Correspondent: Click to Email
To investigate the interaction between chamber wall and fluorocarbon plasmas, various fluorocarbon species such as CF@sub x@ (x=1-3) and C@sub 2@F@sub 4@, C@sub 3@F@sub 5@ emitted from the polymer coated copper stage has been measured by in-situ in C@sub 4@F@sub 8@ inductively coupled plasma using quadrupole mass analyzer (QMA) for the temperature of the stage, the distance between the QMA orifice and the stage. The QMA and hot stage are installed around the center of the chamber and the temperature of chamber wall can be controlled with water cooling system. The copper stage is equipped with heating rod, externally forced nitrogen blowing and can be movable with the radial direction. When we measured the radical density at the distance between hot stage and the orifice over 10 mm at 10 mT of pressure and 500 W of RF power, the results did not show any effect from hot stage and the densities of CF, CF@sub 2@, CF@sub 3@ have an order of 10@super 13@/cm@super 3@, 10@super 13@/cm@super 3@, 10@super 12@/cm@super 3@ respectively. At the distance below 10 mm, however, all radical densities increase and the behavior of CF@sub 3@ radical shows the biggest change with the decrease of the distance. Next, at the distance of 3 mm, the change of radical density with the surface temperature from 50 to 300 ° C was investigated. The density of CF@sub 2@ and CF@sub 3@ decrease slightly up to 100 ° C and 170 ° C, respectively then increase continuously to 300 ° C. The CF@sub 3@ radical density changed also dramatically with the temperature. It goes up to 7x10@super 14@/cm@super 3@ at the surface temperature of 300 ° C. It suggests that the pressure or the number of density around the hot wall is high locally. The increased number of density is due to the emitted species from the hot wall and consists of CF@sub 3@ mostly. It is considered that the surface plays both roles of sink and source of radicals for its temperature and CF@sub 3@ radical is the dominant species emitted from the hot wall inferred from the results measured at 3 mm of the distance with the variation of the surface temperature.