摘要 |
An apparatus is disclosed for coating a semiconductor wafer with polyimide so that excess polyimide is removed from the wafer edge, back side and coating process area and is conveniently drained. A developer, such as dilute TMAH, that mixes with the excess polyimide is injected into a chamber. The soluble mixture of TMAH and excess polymide may then be drained into a bulk drain, obviating the accumulation of excess polymide in the coater cup. The method is implemented through an assembly that includes a coater cup, spin chuck disposed within the coater cup, and a pair of nozzles intruding into the coater cup at a lower portion of the cup. A fist nozzle operates to inject developing fluid onto the back side of the wafer in the cup, and a second nozzle, positioned nearer the center of the cup and the spin chuck, operates to inject rinsing fluid.
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