SUSS MicroTec MA6 mask aligner

Where the used MA6 fits

The SUSS MA6 is a manual contact and proximity mask aligner, and for many teaching and research cleanrooms it is the first lithography tool students use. Buyers looking for a used MA6 usually want one of two things: a reliable aligner for routine micron-scale patterning on 100 mm wafers, or a flexible tool that handles small pieces in the morning and 150 mm wafers in the afternoon.

It suits MEMS, microfluidics, photonics and device teaching labs. It is less suited to work below roughly a micron across a full wafer, where a laser writer or a stepper does better. The MA6 also has close siblings: the MA/BA6 adds bond alignment, and the later Gen3 and Gen4 versions share much of the mechanical layout.

What we inspect on an MA6

Most MA6 problems are mechanical or optical rather than electronic. On inspection we check:

• Lamp house and power supply: lamp hours, ignition, intensity at 365 nm and 405 nm, and the shutter.
• Exposure optics: uniformity across the field, condition of the mirrors and fly's-eye lens, and any clouding from ozone or heat.
• Wedge error compensation (WEC): whether the chuck levels evenly against the mask, which decides contact quality.
• Alignment stage: backlash in the X, Y and theta micrometers and smooth separation travel.
• Vacuum and contact: chuck and mask holder vacuum, seals and the vacuum contact chamber.
• Microscopes: objectives, splitfield function, illumination and any bottom-side optics.

The report lists measured intensity, uniformity and the chucks and holders supplied, with photos.

Refurbishment scope

A refurbished MA6 gets new seals and vacuum lines where they have hardened, a cleaned and realigned optical path, a calibrated intensity sensor and a stage adjusted for minimal play. Worn chucks are lapped or replaced. If the lamp is near its end of life, we fit a new one before testing. A certified unit is also run on a test exposure, and the resolution and overlay results go into the report. See refurbishment for how we grade and document the work.

Upgrades and spare parts

The upgrade most labs ask about is a UV-LED conversion. It removes the mercury lamp, its warm-up time and the lamp disposal routine, and keeps intensity steady between exposures. You need to re-qualify exposure doses afterwards, because the spectrum is not identical to a mercury line. Other common requests are bottom-side alignment, extra chucks for pieces and a camera-based alignment view for teaching.

Facilities

• Single-phase mains power for the tool and the lamp power supply (voltage depending on configuration)
• Vacuum for chuck and mask holder, usually from a house vacuum line or a small pump
• Clean dry air or nitrogen for the pneumatics and contact modes
• Exhaust for the lamp house when a mercury lamp is fitted
• Vibration-isolated table or a stable floor; yellow-light room

Buying advice

Ask for the mask holder and chuck list first, because a used MA6 without the right ones for your wafer size will need parts before it is useful. Check that bottom-side alignment, if listed, is complete with optics and software. Units with heavily worn stages can still be serviced, but budget for the time. Our buying guide for used mask aligners lists what to look at during a visit, and the lithography overview compares the MA6 with the other aligners we handle.