| 摘要 |
PURPOSE:To prolong the lifetime of a quartz diffusion tube by placing a diffusion impurity source and a semiconductor substate in a reaction tube, semisealing the tube, placing the tube in a quartz dfiffusion tube in a double structure type and heating and fiffusing under the prescribed pressure in the diffusion tube. CONSTITUTION:A silicon board 8 filling alumunum 13 as a diffusion impurity source are filled in a quartz reaction tube 6 closed at one side, and the tube is then covered with a quartz inner plug 7. The gap between the tube 6 and the plug 7 is 1mm., and the area of the opening is 1.5cm<2>. This tube 6 is inserted into a quartz diffusion tube 12 connected to a vacuum evacuating device 4 at one side, is substituted for nitrogen gas by an inert gas supply device 10, and is diffused and heat treated while evacuating the tube. In this manner, the lifetime of the quartz diffusion tube can be prolonged. |
