A precision optical instrument used in semiconductor fabrication to align a photomask with a silicon wafer and expose it to ultraviolet light. This process transfers the intricate circuit design onto the photoresist layer coating the wafer. Older contact aligners physically touched the mask to the wafer, while projection aligners use lenses to project the image without contact, preventing mask damage and allowing for finer feature sizes.
Heard on the job
The mask aligner needs a bulb replacement before we can run the next batch of wafers.
Insider tip
In high-volume manufacturing, full-wafer aligners have largely been replaced by steppers and scanners, which expose the wafer in small grid sections to achieve much higher precision.
Also heard as
- mask aligner