RADIO FREQUENCY INDUCTIVELY COUPLED PLASMA GENERATOR CONFINED USING MAGNETIC FIELD PRODUCED BY FIELD COIL WITH SOFT MAGNETIC MATERIAL SHELL

摘要

A radio frequency inductively coupled plasma generator confined using magnetic field produced by field coil with soft magnetic material shell mainly includes radio frequency induction coils (4), a soft magnetic material shell (5) with an inner annular gap, excitation copper coils (6) for generating a confining magnetic field, an air inlet pipeline (1), an outer shell (2), a workpiece support (3), a vacuum obtaining system (7), a vacuum measuring system and a control system. The soft magnetic material shell (5) with the inner annular gap enables magnetic lines which are excitated by the excitation copper coil (6) for generating the confining magnetic field to be concentrated close to the inner annular gap of the shell (5). The magnetic induction intensity of the centre region of the generator is significantly increased, thus the trajectory of the charged particles is greatly extended. The collision times between the charged particles and the gas molecules are significantly increased, so high density plasma can be achieved in lower pressure and the distribution of the plasma is improved.