PURPOSE: To enable the maintenance of stable plasma and improve the efficiency of reaction in the plasma by rounding the edge part of a cylindrical member for reaction gas supply to the plasma where opposite to the plasma.
CONSTITUTION: A cylindrical member 10 has an edge part rounded where the surface thereof is opposite to plasma P. In this constitution, a gas flow between the member 10 and a nozzle 5 is toward an arrow A', and presses the plasma P in such a way as to enclose and stably keep the plasma P. On the other hand, reaction gas from a reaction gas feed port 8 between the member 10 and a pipe 2 flows in an arrow B' direction and causes the flow of the reaction gas into the plasma P efficiently. According to the aforesaid construction, the approach of the plasma P to the nozzle 5 can he prevented while the plasma P is being kept stable, and the reaction gas can be efficiently fed into the plasma P.
TERAJIMA KAZUO
KOMAKI HISASHI
