Microwave transforming method and plasma processing

摘要

PCT No. PCT/JP88/00401 Sec. 371 Date Oct. 19, 1988 Sec. 102(e) Date Oct. 19, 1988 PCT Filed Apr. 25, 1988 PCT Pub. No. WO88/08659 PCT Pub. Date Nov. 3, 1988.In a plasma processing apparatus, a gas to be activated into a plasma is introduced into a plasma formation chamber through a gas introducing pipe. Input microwave energy from a microwave source is also supplied to the plasma formation chamber, so that the introduced gas is activated into the plasma by electron cyclotron resonance. The input microwave energy in a TE mode from the microwave source is received by a tapered waveguide in which a dielectric plate is accommodated, so that at least a part of the input microwave energy is transformed into microwave energy in a TM mode or hybrid mode having an electric field component in the direction of the propagation of the input microwave. Microwave energy in both the modes is introduced into the plasma formation chamber through a microwave introducing window. As a result, the microwave energy in the propagation mode having an electric field component or a longitudinal wave component which is parallel to the direction of the microwave propagation is introduced into the plasma formation chamber. The microwave energy is efficiently supplied to the plasma region which satisfies the ECR conditions and then is absorbed by the plasma. Thus the efficiency of the plasma formation is enhanced and accordingly the throughput of the plasma processing is improved.