| 摘要 |
PURPOSE:To improve production yield by preventing foreign matters from adhering to a wafer, by providing a treating chamber, for heat treatment of a wafer, with a gas circulating passage designed for allowing clean gas to pass downwards, and by keeping gas pressure in the treating chamber to positive pressure in comparison with atmospheric pressure. CONSTITUTION:An inert gas, sent into a circulating chamber 3 from a gas supply pipe 4, passes through filters 14 and 15, enters a baking chamber from a ventilating chamber 7, flows downwards by action of a mesh plate 5 carrying down foreign matters produced in a driving unit of a conveying step 16 and flows into a ventilating chamber 9 through a mesh plate 6, so that foreign matters in the baking chamber can be removed. On the other hand, a wafer 17 is made to pass through a conveying entrance 20 and conveyed into the baking chamber by the conveying step 16, where it is provided with heat treatment and conveyed out from an exit 22. At this time, positive pressure is maintained in the baking chamber by adjusting gas flow so that foreign matters contained in atmosphere can be prevented from entering at the time of conveying in and out of the wafer. it is possible, by doing so, to prevent the foreign matters from adhering to a coating. |
