| 摘要 |
PURPOSE:To perform uniform diffusion which roughness on the substrate surface is little by using N2 gas containing the O2 of specified percent as carrier gas in impurity diffusion, in which an antimonial oxide is used as a diffusion source. CONSTITUTION:In an opening tube 1 to whose outside a heater 4 is mounted, an antimonial oxide is diffused as an impurity to a substrate 3 of monocrystal silicon, etc. supported by an internal quartz plate 2. Thus, each gas is introduced controlling pressure by a flow rate controller 8 installed among each gas feeder and an introducing pipe 9, which is coupled with one end of opening tube 1, from a N2 gas feeder 5, an impurity gas feeder 7 and an O2 gas feeder 6, which are each connected to pipe 9. In this case, the concentration of O2 contained in carrier gas is set to the value of 0.4-0.8 to the N2 gas. When the concentration of O2 is kept within a range of the above-mentioned numerical value, the dispersion of impurity diffusion in the substrate is reduced and the roughness of the surface can be decreased. |
