OXIDATION APPARATUS

PURPOSE:To obtain stable combustion flames and to enable a thin oxide film to be formed with less contamination and fewer defects with a desirable controllability, by controlling the pressure of oxygen within a combustion chamber for supplying a required amount of water vapor to an oxidation chamber and capable of realizing stable combustion under a decreased pressure, such that the pressure of oxygen is close to an atomospheric pressure, while ejecting hydrogen from a nozzle under a pressure higher than the atmospheric pressure. CONSTITUTION:Water vapor produced by combustion is introduced into a decompressed oxidation chamber 1 through a small hole 4 provided in a partition wall 5 of quartz, and an object arranged within the oxidation chamber 1 is oxidized. The degree of aperture of the small hole 4 can be regulated by means of a needle 6 for regulating the pressure within a combustion chamber 2. When this device is utilized for forming a thin oxide film on silicon, the flow rates of hydrogen and oxygen introduced to a nozzle 3 are 2.0l/min and 1.5l/min, respectively. Further, in order to prevent dangerous accidents such as explosion, oxygen is used in a somewhat richer amount with respect to the ratio of reaction. The oxidation of decompressed water vapor can be stabilized under the pressure P0 in the oxidation chamber 1 of 10 Torr and the pressure PB in the combustion chamber 2 of 450 Torr, and a thin oxide film with a thickness of about 100Angstrom can be formed with a desirable controllability at an oxidation rate from 10 to several 10Angstrom /min.