| 摘要 |
PURPOSE:To improve uniformity in a wafer and between wafers by a method wherein in a device being in depressurized condition at less than one atmospheric pressure and is heating substrates, an imprity soutce consisted of a gaseous body or evaporated gas from a liquid is introduced and is made to diffuse. CONSTITUTION:The plural wafers 3 put on a jig 2 are accomodated in a quartz tube 1, and are heated at the prescribed temperature. In the depressuized condition of the inside of quartz tube by a vacuum pump 5, the impurity gas is supplied from an evaporator 7 of a liquid diffusion source (BBr3, etc., for example) held at a constant temperature with an electronic cooling and heating devidce 6, for example. Because the inside of the quartz tube is held at the depressuized condition and impurity gas in the quartz tube has the large average free path, the impurity gas collides with the respective wafers equally and diffuses uniformly. Accordingly deteioration like a solid diffusion source is not generated on the diffusion source, and intermixing of contamination can be also prevented. |
