What is a reticle?
The term Photomask (sometimes abbreviated to Mask) is used to mean any type of glass plate with a pattern etched into an opaque surface. A Reticle is a special type of photomask where the data for only part of the final exposed area is present. A Reticle is loaded into a Stepper or Scanner system where multiple exposures are made to cover the full patterned area. Most modern reticles have the features scaled up by 5X or 4X of the final image size and the features will be reduced in scale as the Reticle is exposed. Other scale factors such as 2X, 2.5X and 10X are also possible. Ultratech Reticles are a special case where the data is at a scale of 1X. When ordering a Reticle, special features for alignment called fiducials also need to be added to the mask. The design of these fiducial features will depend on the manufacturer of the stepper or scanner used. Most steppers and scanners also allow the user to place a barcode on the reticle which can be read on the system as the reticle is used. Compugraphics makes a wide range of reticles and can advise customers on the additional patterns that need to be added.
