| 摘要 |
PURPOSE:To detect coating defects and development defects caused by the lack of chemical solution in an early stage and take corrective action and improve the yield by providing a sensor which monitors the feeding status of the chemical solution from a nozzle. CONSTITUTION:Chemical solution 3 is dropped from a nozzle 2 provided above a wafer 1 onto the wafer 1 which is vacuum-attracted by a base 5 which has a vacuum attraction function. The chemical solution 3 fed from the nozzle 2 is dropped through a chemical solution recognizing sensor 4 which utilizes a photosensor provided below the nozzle 2. While the chemical solution is fed ensuredly, the light path of the photosensor is blocked but, if the chemical solution is not fed, no change occurs in the light path. This status is monitored by a control unit and, if something abnormal happens, an alarm is transmitted to alert an operator. |
