| 摘要 |
PURPOSE:To obtain an insulation film with a uniform and excellent quality by introducing each gas so that SiH4 or SiH4 and PH3 are mixed in a growing region in vapor phase and that O2 is distributed evenly in the region and by performing vapor growth under the reduced pressure. CONSTITUTION:An Si substrate 22 is arranged on a plate 23 in a growth region inside a reaction tube 21 and SiH4 or SiH4 and PH3 are introduced 24 therein. Then, O2 gas is introduced through pipes 25 and 25' inserted from both ends of the reaction tube. The pipes 25 and 25' have a plurality of orifices in the part of the growth region, and O2 gas is distributed evenly in the growth region and mixied with SiH4 or with SiH4 and PH3 in and around the growth region, whereby SiO2 or PSG is grown in vapor phase in the surface of the substrare. The growth region is heated 26 at about 500 deg.C and the gases are exhausted, thereby the inside of the tube being kept at about 1Torr. By this constitution, the thickness of a film on each substrate is distributed uniformly without any production of faulty growth film. The molar ratio of O2/SiH4 is selected to be 1-1.8. In addition, the molar ratio of PH3/SiH4 is selected according to the density of P added to SiO2. By this method, the uniform insulation film can be obtained at high speed of growth. |
