Photoresist Supply Level Detection and Manifold System
Original Publication Date: 1987-Jan-01
Included in the Prior Art Database: 2005-Jan-31
During semiconductor manufacturing operations, it is necessary to provide a source of photoresist for photolithography. The photoresist is applied to a wafer and dried prior to exposure. A typical photoresist application system includes a supply container connected to a manifold from which a positive displacement pump draws suction for individual application stations. The present apparatus includes a detection system to alert an operator when the photoresist supply container is emptied, and a reservoir to provide a sufficient supply of photoresist to complete a run. In practice, it is not uncommon for operators to replace a photoresist supply can prior to its being completely emptied. This assures that a run will not be interrupted for lack of photoresist.