PURPOSE: To prevent the formation and sticking of flakes of fine foreign matter particles to nozzle ends and inside wall surface by providing many pieces of reactive gas feed nozzles into coaxial multiple-layer structure to the central top of a bell-jar and providing plural pieces of the respective gas supply ports thereof symmetrically with the central axis of the nozzles.
CONSTITUTION: Three piece of the reactive gas feed nozzles 20, 30, 40 are arranged in the coaxial multi-layer structure to the central top of the bell-jar 3 and four pieces of the gas supply ports 24, 34, 44 are respectively provided symmetrically with the central axis of the nozzles on the outer peripheral face of disk-shaped gas reservoirs 22, 32, 42 of the respective nozzles 20, 30, 40. Gaseous O2 is fed from a 1st nozzle 20 and the 3rd nozzle 40 respectively and the reactive gas such as SiH4 and/or PH3 except O2 is fed from the 2nd nozzle 30 to form the thin film on a wafer in the above-mentioned constitution. The formation and sticking of the flakes of fine oxide particles of SiO2, SiO,etc., on the nozzle ends and the inside wall surface are thereby effectively prevented and the flow velocity of the reactive gas fed into the furnace is kept constant. The thin film having a uniform film thickness is thus formed.
HIKIMA HITOSHI
TAKAMI KATSUMI
TANIGUCHI KAZUO
KISHIMOTO SATORU
