TIME-RESOLVED STUDY OF A REACTIVE LOW-PRESSURE PLASMA - DETERMINATIONOF BASIC DATA ON ELECTRON-FLUORINE COLLISIONS

Time resolved spectroscopy and electron concentration measurements wer e performed on an Ar-He-F-2 mixture excited by an external rf antenna creating a plasma with features of a plasma source generated by a Heli con reactor commonly used in materials processing. The low pressure ra nge and the simplified chemistry allow an appropriate modelling of som e processes and lead to the determination of some fundamental data con cerning atomic and molecular fluorine. We give a F-2 direct dissociati on coefficient by electron impact of about 2.0X10(-9) cm(3) s(-1) for an electron temperature of 5 eV. Excitation rate coefficients of some fluorine levels (3p(2)P(3/2),3p(4)D(7/2), and 3p'F-2(7/2)) are given a s well as rate coefficients of line emissions following F-2 dissociati on by electron impact. (C) 1995 American Institute of Physics.