| 摘要 |
PURPOSE:To oxidize the surface of a wafer with a large diameter uniformly by oxidizing the wafer while keeping total pressure in a reaction pipe to atmospheric pressure or less. CONSTITUTION:The inside of the quartz reaction pipe 2 is kept to one atmospheric pressure or less, and an oxidizing gas 5 containing O2, H2O or O2 is forwarded into the reaction pipe, and heated 6 at a high temperature. Since an atmosphere is brought to atmospheric pressure or less, the diffusion velocity of the gas in the reaction pipe increases, and the uniformity of the thickness of an oxide film is improved in the peripheral section and central section of the wafer 1. The improvement is particularly remarkable especially when the diameter of the wafer is 1cm or more. When the inside of the reaction pipe is brought to low pressure, the growth rate of the oxide film slows down, but trouble is not generated practically when O2 is used as a raw material gas or the raw material gas is changed into plasma and increased. |
