| 摘要 |
PURPOSE:To regenerate a same diffusion layer with use of a same sealed tube container with high reliability by forming Si3N4 film on inside wall of the sealed tube container thereby sealed quantity of Ga or mixture of Ga and Ge can be reduced. CONSTITUTION:Si3N4 film 8 of 500-1,500Angstrom is formed at 600-700 deg.C with use of mixture gas of NH3 and SiH4 on surface of a silica plate used for a silica sealed tube container 1 and Si substrate take-out port. After a board 3 on which a diffusion supply source 5 and Si substrate 6 is mounted on center of the sealed tube 1 through the Si substrate take-out part, a silica plate used for the Si substrate take-out port is welded with the silica sealed O2, H2, burner tube container 1 by an oxyhydrogen burner. After welding the container 1 is made vacuous up to 10<-6>-10<-7>Torr and is introduced inert gas and then an inert gas introducing aperture 7 is welded to be chipped off. The container 1 is put in a diffusion oven in order to obtain desired height of the diffusion layer and desired density of surface and temperature and time of diffution is preset. Thus the method of diffusion by coating an inside wall of a diffusion container with Si3N4 enables to save various presetting as well as to reduce sealed quantity of Ga or mixture of Ga and Ge as diffusion source. |
