620

A mask aligner is an optical lithography tool that aligns a patterned mask to a resist-coated substrate and then exposes the resist. Mask aligners are used when a process requires patterned transfer without the projection optics architecture of a stepper or scanner.

The EVG620 NT is a mask alignment system available in semi-automated or automated configuration. The EVG620 NT supports wafer or substrate sizes from pieces up to 150 mm and uses either a mercury light source or a UV LED light source. The EVG620 NT supports top side alignment, bottom side alignment, IR alignment, bond alignment, and NIL alignment. The EVG620 NT offers vacuum contact, hard contact, soft contact, proximity mode, and flex mode exposure setups. The EVG620 NT also includes fully automatic software-controlled wedge compensation.^[4]

Mask alignment is a lithography step performed after photoresist coating and before resist development. The exposure produced by a mask aligner defines the resist image that is later transferred by etch, plating, lift-off, implantation masking, or related patterning steps.

Mask aligners are commonly used for device and package fabrication that benefits from direct mask exposure, substrate-side registration, or processing on substrates that are difficult to handle in projection lithography tools. Typical use cases include resist patterning for etch masks, metal definition, lift-off, cavity formation, and alignment-sensitive work on transparent, thick, thin, or warped substrates.