| 摘要 |
PURPOSE:To reduce wastage of a quartz tube of an apparatus for manufacturing semiconductor devices by vacuum CVD, reducing the adhesion of boron or the like during the formation of a polycrystalline film, by providing dummy materials on the discharge orifice side of the quartz tube. CONSTITUTION:A quartz tube 1, which is disposed in an apparatus for forming a coat on the surface of a semiconductor substrate 2 by vacuum CVD, is provided with a holding frame 3 in its central portion where treatment conditions are stable, and a plurality of substrates 2 are arranged vertically on the frame 3. Dummy materials 10 are arranged on the discharge orifice 6 side. The quartz tube 1 is evacuated of gas through the discharge orifice 6 and is heated while retaining a predetermined temperature gradient. When an N type polycrystalline silicon film is formed, monosilane gas or a mixture of monosilane and inactive gases is introduced through treating gas induction orifices 5a and 5b. When the excessive gas thus introduced is discharged from the discharge orifice 6, the subject gas is caused to penetrate into the dummy materials so that a large quantity of phosphorus is deposited on the surfaces of the dummy materials 10. In such a manner, the wastage of the quartz tube 1 can be reduced. |
