| 摘要 |
PROBLEM TO BE SOLVED: To always keep the ammonia concentration of at least the peripheral region of a substrate in a chamber at a low concentration.SOLUTION: When processing a substrate (W), intake air sucked from the external space of a chamber (20) is supplied into the chamber via an intake air flow path (211) and a filter (214) for removing particles. Ammonia concentration of the intake air is measured, and depending on the ammonia concentration thus measured, a clean gas not containing or scarcely containing ammonia, in the intake gas before arriving at the substrate, e.g., dry air or nitrogen gas, is supplied and mixed with the intake gas. With such an arrangement, the ammonia concentration of the atmosphere at least in the peripheral region of the substrate in the chamber is maintained to equal to or below a predetermined value.SELECTED DRAWING: Figure 2 |
