3 HR Mask Aligner UV Exposure

The ABM 3 HR Mask Aligner / UV Exposure System is a lithography tool used for mask alignment and ultraviolet exposure in microfabrication. It is configured with a precision alignment stage, a mask holder sized for a four inch by four inch area with a three inch diameter substrate holder, and a splitfield Zeiss microscope for alignment.^[1]

A mask aligner holds a photomask and a substrate in a controlled alignment relationship, then uses ultraviolet light to transfer the mask pattern to the light-sensitive surface on the substrate. The alignment stage and microscope support registration before exposure.

In this class of equipment, the mask and substrate are positioned so that exposed areas receive the intended pattern during the exposure step, while unexposed areas remain protected. The optical viewing path assists the operator in bringing the two surfaces into the required alignment before illumination.

This equipment sits in the lithography portion of a fabrication flow, after a substrate has been prepared with a light-sensitive coating and before pattern development and later process steps. It is used when a process requires direct alignment between a mask and a substrate.

Mask aligners are used for pattern transfer on photosensitive substrates in microfabrication, including work on semiconductors, microelectromechanical structures, and other fine-pattern planar processes. They are used where repeatable mask-to-substrate registration is needed for ultraviolet exposure.