| 摘要 |
PURPOSE:To uniformalize the treatment and improve the yield by a method wherein a reactor is connected with the local exhaust portion by a first and second pipes, and at least the first pipe is provided with a valve and made thicker than the diameter of the second pipe. CONSTITUTION:The connecting pipe 5 of a reactor 1 and the local exhaust portion 4 are connected by pipes 9a, 9b, which have valves 10a, 10b, respectively. The ratio of the opening areas between the pipes 9a, 9b is, for instance, 4:1. At the oxidation or impurity diffusion time, the valve 10a is closed, and the gas in the reactor is exhausted through the pipe 9b. This causes the pressure loss between the reactor and the local exhaust portion to become large, and pressure deviation within the reactor can be controlled to be small, so that the thickness of the oxide film and the concentration distribution of an object to be treated 3 become stable. When the object to be treated enters or exit, both valves are opened, making the pressure loss small. Therefore, the mist adhering to the vicinity of the reactor entrance, which is generated by a reaction product 12 such as P, is forcibly exhausted along with the gas within the reactor, so that the reaction product 12 does not adhere to the surface of the object to be treated. |
