Photoresist coating failure sensing methods and detection devices
View Patent ↗Methods and devices for detecting photoresist coating failures are disclosed. A disclosed method to detect a photoresist coating failure on a semiconductor wafer comprises: loading a photoresist coated wafer on a notch position check block; rotating the coated wafer; detecting the position of a notch in the wafer; blowing air toward the surface of the wafer with at least one air nozzle located over the rotating wafer; detecting an amount of the air blown from the at least one air nozzle; and generating a coating failure signal if a variation in the amount of air blown from the at least one air nozzle is indicative of a photoresist coating failure.
1. A device to detect photoresist coating failures comprising:
a sensor to detect the position of a notch in a rotatino wafer, the sensor being capable of detecting the notch while the wafer is rotating;
at least one nozzle positioned over the rotating wafer to blow gas perpendicularly toward the rotating wafer;
at least one gauge to detect an amount of gas blown through the at least one nozzle; and
a control device to identify a photoresist coating failure based on an output of the at least one gauge.
2. A device as defined in claim 1 , further comprising a display device in communication with the control device to display information indicative of a photoresist coating failure if a photoresist coating failure is identified by the control device.
3. A device as defined in claim 1 , wherein the at least one nozzle is placed horizontally over a radius of the wafer.
4. A device as defined in claim 1 , wherein the at least one nozzle is positioned about 3 to 8 mm above the wafer.
5. A device as defined in claim 1 , wherein a diameter of each of the at least one nozzle is about 3 mm.
6. A device as defined in claim 1 , wherein the at least one nozzle comprises eighteen air nozzles arranged in 2 rows and 9 columns.
7. A device as defined in claim 1 , wherein the gas is air.